CN112965508B - Multi-information feedback electric parallel wheel-foot robot walking control method and system - Google Patents
Multi-information feedback electric parallel wheel-foot robot walking control method and system Download PDFInfo
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Abstract
The invention discloses a foot type stable walking control method and system of an electric parallel wheel-foot robot with multi-information feedback, wherein the system comprises the following steps: the system comprises an upper layer control system, a middle layer control system and a bottom layer control system; the upper control system comprises a decision module; the middle-layer control system comprises an attitude adjustment controller, a ground contact detector, a foot force distribution controller, a gravity height controller, a foot end track planner, a subtracter and an adder; the bottom layer control system comprises a foot end force and position resolving module, a wheel leg controller of each wheel leg, an electric cylinder controller of each wheel leg, a machine body attitude sensor arranged on a wheel leg robot, and a force and position sensor arranged at the tail end of the electric cylinder of each wheel leg. The invention can improve the stability of the robot walking in a foot mode under the rugged terrain, solve the problem of small moving space of the robot legs with the parallel structure and avoid the phenomenon that the elongation of the legs is shorter or longer.
Description
Technical Field
The invention belongs to the technical field of robot motion driving and control, and particularly relates to a foot type stable walking control method and system for an electric parallel wheel-foot robot based on multi-information feedback.
Background
The mobile robot has the advantages of high movement speed and high efficiency, can be widely applied to the fields of material transportation, emergency rescue and the like, but has improved requirements on the adaptability of the robot under rugged terrains, and is easy to have the phenomena of unstable gravity center, inclined posture, insufficient activity space of the leg execution electric cylinder and the like. When the robot walks on a rugged terrain, the robot body inclines along with the rise and fall of the terrain, and the gravity center of the robot body deviates from the supporting polygon, so that the instability of the robot is easily caused, and materials on the platform fall off. In addition, under the rugged terrain, the maximization of the movement space of the electric cylinder for executing the robot legs with the parallel structure is a key factor for determining whether the robot can better adapt to the complex terrain.
At present, the foot type stable walking of the mobile robot under the rugged terrain is mainly focused on the compliance control and the attitude control.
The compliance control mainly comprises the steps of collecting force signals through a multi-dimensional force sensor arranged at a foot end, carrying out difference with expected foot end force, and inputting the force deviation into an impedance controller to obtain the variation of the position of the foot end, so that the effect of compliance grounding is realized. However, the multidimensional force sensor installed at the foot end is easy to be subjected to larger impact force, the force information acquisition data is unstable, and the reliability of the system is poor.
In the aspect of attitude control, many scholars regard the expected attitude angle as the horizontal state of the machine body, namely the expected attitude angle is kept at zero degrees, so that the advantage that the machine body is always kept in the horizontal state under the complex terrain of robot walking is achieved; however, it is not considered that the robot moves on a slope, and if the body of the robot keeps horizontal, the movement space of the robot legs is limited, and the problem is particularly obvious for the robot with a parallel structure. Therefore, for the robot with the parallel-type structure legs, the stable movement of the robot body is ensured and the movement space of the legs is increased in the aspect of attitude control.
Disclosure of Invention
In view of this, the invention provides a multi-information feedback foot-type stable walking control method and system for an electric parallel wheel-foot robot, which can improve the stability of foot-type walking of the robot under rugged terrain.
In order to solve the above-mentioned technical problems, the present invention has been accomplished as described above.
A multi-information feedback foot type stable walking control method for an electric parallel wheel-foot robot comprises the following steps:
determining the expected attitude angle (alpha) of the body of the wheel-foot robot according to the external topographic informationd,βd) Desired height of center of gravity of each wheel leg
And step(s)A state parameter;
according to the desired attitude angle (alpha)d,βd) And the actual attitude angles (alpha, beta) of the machine body are subjected to attitude adjustment decoupling control, and the extension quantity delta p of each support phase leg i in the Z direction of the wheel leg coordinate system is generated by taking the expected attitude of the machine body as a targetiz；
The detection value is obtained by utilizing the force and position sensors arranged at the tail ends of the electric cylinders of the wheel legs, and the actual foot end contact force F of each wheel leg is solved through inverse solution calculation of the kinematics and dynamics of the wheel-foot robotizAnd the Z-direction position p of the foot endiz；
After the swing phase leg is converted into a support phase leg i by touching the ground, the gravity center of the robot with the wheel feet is positioned in the support polygon as the target, and the contact force F of the foot end of the support phase leg is usedizThe foot force is distributed to generate the adjustment quantity (delta p) of the horizontal position of the gravity center which can eliminate the external force and the external moment at the foot endix,△piy)；
According to desired height of center of gravity
And the actual Z-direction position p of the foot endizThe difference in gravity center height adjustment is generated with the aim of supporting the phase leg to maintain a desired gravity center height
Performing foot end trajectory planning according to the gait parameters to generate foot end poses of each wheel leg, and inputting the foot end poses into wheel leg controllers of the support phase legs and the swing phase legs;
will support the amount of expansion Δ p of the phase leg iizAdjustment of height of center of gravity
The sum is used as the adjustment amount of the height position of the gravity center, together with the adjustment amount of the horizontal position of the gravity center (Deltap)ix,△piy) The wheel leg controllers are input into the supporting phase leg i together, and are used for adjusting the pose of the foot end and further performing inverse kinematics to the electric cylinder, so that the supporting phase leg moves at the expected gravity height; wheel for swinging photo legsAnd the leg controller calculates the control quantity of the electric cylinder according to the pose of the foot end to realize the control of the swing phase leg.
Preferably, for the electric parallel six-wheel-foot robot realized by using a Steward platform, the delta pizThe acquisition mode is as follows:
△pβ＝l·sin(|β-βd|)/2
if the No. 1, 3 and 5 wheel legs are in the supporting phase:
when alpha is>αdAnd beta is>βd，△p1z＝-△pα/2-△pβ/2,△p3z＝△pβ/2,△p5z＝△pα/2-△pβ/2
When alpha is>αdAnd beta is<βd，△p1z＝-△pα/2-△pβ/2,△p3z＝Δpβ/2,△p5z＝△pα/2+△pβ/2
When alpha is<αdAnd beta is>βd，△p1z＝△pα/2-△pβ/2,△p3z＝Δpβ/2,△p5z＝△pβ/2-△pα/2
When alpha is<αdAnd beta is<βd，△p1z＝△pα/2+△pβ/2,△p3z＝-△pβ/2,△p5z＝△pβ/2-△pα/2
If the No. 2,4 and 6 wheel legs are in the supporting phase:
when alpha is>αdAnd beta is>βd，△p2z＝-△pα/2+△pβ/2,△p4z＝△pα/2+△pβ/2,△p6z＝-△pβ/2
When alpha is>αdAnd beta is<βd，△p2z＝-△pα/2-△pβ/2,△p4z＝△pα/2-△pβ/2,△p6z＝Δpβ/2
When alpha is<αdAnd beta is>βd，Δp2z＝Δpα/2+Δpβ/2,Δp4z＝Δpβ/2-Δpα/2,Δp6z＝-Δpβ/2
When alpha is<αdAnd beta is<βd，Δp2z＝Δpα/2-Δpβ/2,Δp4z＝-Δpα/2-Δpβ/2,Δp6z＝Δpβ/2
Wherein l is the distance between the right front leg and the right rear leg of the wheel-leg robot.
Preferably, the gravity center height adjustment amount
The acquisition mode is as follows: desired height of center of gravity of each support phase leg
And the actual Z-direction position p of the foot endizThe average of the difference is the adjustment amount of the height of the center of gravity
Preferably, the desired height of the center of gravity of each wheel leg
The same is true.
The invention provides a multi-information feedback foot type stable walking control system of an electric parallel wheel-foot robot, which comprises: the system comprises an upper layer control system, a middle layer control system and a bottom layer control system; the upper control system comprises a decision module; the middle-layer control system comprises an attitude adjustment controller, a ground contact detector, a foot force distribution controller, a gravity height controller, a foot end track planner, a subtracter and an adder; the bottom layer control system comprises a foot end force and position resolving module, a wheel leg controller of each wheel leg, an electric cylinder controller of each wheel leg, a machine body attitude sensor arranged on a wheel leg robot and a force and position sensor arranged at the tail end of the electric cylinder of each wheel leg;
the decision module is used for determining the expected attitude angle (alpha) of the body of the wheel-foot robot according to the external terraind,βd) Desired height of center of gravity of each wheel leg
And a gait parameter; the desired attitude angle (alpha) of the fuselaged,βd) Sending to the attitude adjustment controller to adjust the desired center of gravity height
Sending the gait parameters to a subtracter and sending the gait parameters to a foot end track planner;
the attitude adjustment controller is used for adjusting the attitude according to the expected attitude angle (alpha) of the fuselaged,βd) And the actual attitude angles (alpha, beta) of the fuselage, which are acquired by the attitude sensor of the fuselage, are subjected to attitude adjustment decoupling, and the extension quantity delta p of each support phase leg i in the Z direction of the wheel leg coordinate system is generated by taking the expected attitude of the fuselage as a targetizSending the data to an adder;
the foot end force and position calculating module is used for calculating the actual foot end contact force F of each wheel leg through inverse solution calculation of the kinematics and dynamics of the wheel-foot robot by utilizing the detection values of the force and position sensorsizAnd the Z-direction position p of the foot endizResolving is carried out;
the touchdown detector is used for converting the actual foot end contact force F of the support phase leg i after judging that the swing phase leg touchdown is converted into the support phase leg iizFoot end contact force FizSending the position p in the Z direction of the foot end of the supporting phase leg i to a foot force distribution controllerizSending to the subtracter;
the foot force distribution controller is used for targeting that the gravity center of the wheel-foot robot is positioned in the support polygon according to the foot end contact force F of the support phase legizThe foot force is distributed to generate a horizontal position of the gravity center which can eliminate the external force and external moment at the foot endAdjustment amount (Δ p)ix,Δpiy) The data are sent to the wheel leg controllers of the corresponding supporting phases;
the subtracter calculates
The result of (1) is sent to the center of gravity height controller;
the center of gravity height controller for targeting the support phase leg to maintain a desired center of gravity height, based on
To produce the adjustment amount of the gravity center height
Sending the data to the adder;
the adder is to
The measured data is sent to a wheel leg controller of a corresponding support phase to be used as the adjustment quantity of the height position of the gravity center;
the foot end track planner is used for planning foot end tracks according to the gait parameters, generating foot end poses of the wheel legs and sending the foot end poses to the wheel leg controllers of the support phase legs and the swing phase legs;
the wheel leg controller for supporting the phase leg is used for adjusting the amount according to the height position of the center of gravity
Adjustment quantity (delta p) of horizontal position of center of gravityix,△piy) Adjusting the pose of the foot end, and further performing inverse kinematics to an electric cylinder to enable the support phase leg to move at the expected gravity height;
and the wheel leg controller of the swing leg is used for resolving the control quantity of the electric cylinder according to the foot end pose and sending the control quantity to the corresponding electric cylinder controller.
Preferably, for the electric parallel six-wheel-foot robot realized by using a Steward platform, the attitude adjustment control adopts the following formula to calculate delta piz：
△pβ＝l·sin(|β-βd|)/2
If the No. 1, 3 and 5 wheel legs are in the supporting phase:
when alpha is>αdAnd beta is>βd，△p1z＝-Δpα/2-Δpβ/2,Δp3z＝Δpβ/2,Δp5z＝Δpα/2-Δpβ/2
When alpha is>αdAnd beta is<βd，Δp1z＝-Δpα/2-Δpβ/2,Δp3z＝Δpβ/2,Δp5z＝Δpα/2+△pβ/2
When alpha is<αdAnd beta is>βd，△p1z＝△pα/2-△pβ/2,Δp3z＝Δpβ/2,△p5z＝△pβ/2-△pα/2
When alpha is<αdAnd beta is<βd，△p1z＝△pα/2+△pβ/2,△p3z＝-△pβ/2,△p5z＝△pβ/2-△pα/2
If the No. 2,4 and 6 wheel legs are in the supporting phase:
when alpha is>αdAnd beta is>βd，△p2z＝-△pα/2+△pβ/2,△p4z＝△pα/2+△pβ/2,△p6z＝-△pβ/2
When alpha is>αdAnd beta is<βd，△p2z＝-△pα/2-△pβ/2,△p4z＝△pα/2-△pβ/2,△p6z＝△pβ/2
When alpha is<αdAnd beta is>βd，△p2z＝△pα/2+△pβ/2,△p4z＝△pβ/2-△pα/2,△p6z＝-△pβ/2
When alpha is<αdAnd beta is<βd，△p2z＝△pα/2-△pβ/2,△p4z＝-△pα/2-△pβ/2,△p6z＝△pβ/2
Wherein l is the distance between the right front leg and the right rear leg of the wheel-leg robot.
Preferably, the center of gravity height controller acquires a center of gravity height adjustment amount
The method comprises the following steps: for supporting the legs individually
Averaging to obtain the gravity center height adjustment
Preferably, the upper control system comprises a perception module for recognizing external terrain and sending the external terrain to the decision module.
Has the advantages that:
the invention is realized by a foot force distribution controller, an attitude adjustment controller and a gravity center height controller based on force feedback.
(1) The foot force distribution controller solves the problem of stability margin of the gravity center of the robot, eliminates external force and external moment at the foot end through the foot force distribution controller to realize horizontal position adjustment of the gravity center, and ensures that the gravity center of the robot is positioned in a supporting polygon.
(2) The attitude adjustment controller is used for adjusting the attitude of the robot body, ensuring that the actual attitude angle tracks the expected attitude angle when the robot walks on the rugged terrain, and the expected attitude angle is determined by the upper-layer control system, so that the robot is suitable for various types of rugged terrain and is not required to be maintained at a fixed angle as in the prior art. Meanwhile, the attitude adjustment controller decouples the variation of the attitude angle of the body to the variation of six electric cylinders of the support phase leg, so that the electric cylinders stretch smoothly, and stable tracking and adjustment of the expected attitude angle of the body are realized.
(3) The gravity center height controller refers to a controller for controlling the height of the gravity center of the robot passing through the body. The gravity center height controller solves the problem that the moving space of the robot legs with the parallel structure is small, and can acquire the expected gravity center height according to topographic information, so that each leg is kept near the expected height in the walking process of the robot, and the fluctuation and the jolt of the gravity center of the robot body are reduced; meanwhile, the gravity center of the robot body is maintained at an expected height, so that the extension amount of the support phase leg is kept near the expected length, the support phase leg can have a larger movement space in the lower period, the phenomenon that the extension amount of the leg is shorter and shorter or longer and longer in the walking process is avoided, the electric cylinder of each support phase leg is ensured to have the largest telescopic activity space, and the six-wheeled legged robot can walk stably in a foot-type mode on rugged terrain.
(4) Compared with a multidimensional foot force sensor installed at the foot end of the robot, the calculation based on the foot end force can not only reduce the impact on the foot end force sensor, but also enable the force information acquisition data to be more stable. Therefore, the foot end force is calculated by utilizing the component force values acquired by the six end force sensors of the electric cylinder, and the reliability of the system can be greatly improved.
(5) The command signals of the expected attitude angle, the expected height and the like of the attitude adjustment controller and the gravity center height controller are transmitted to the middle-layer controller by the sensing system module, the command signals are generated by the decision module in the upper-layer control system, and the command signals of the expected attitude angle, the expected height and the like can be adaptively adjusted according to the external topographic information.
Drawings
Fig. 1 is a schematic view of a foot type stable walking control scheme of the electric parallel wheel-foot robot based on multi-information feedback.
Fig. 2 is a schematic diagram of the attitude adjustment controller.
Fig. 3 is a schematic diagram of the principle of the center of gravity height controller.
Detailed Description
The invention is described in detail below by way of example with reference to the accompanying drawings.
The invention provides a foot type stable walking control method of an electric parallel wheel-foot robot with multi-information feedback, as shown in figure 1, the method comprises the following steps:
step 1, determining the expected attitude angle (alpha) of the body of the wheel-foot robot according to the external topographic informationd,βd) Desired height of center of gravity of each wheel leg
And gait parameters.
Wherein the desired height of the center of gravity of each wheel leg
The same or different. The purpose of this step is to be able to automatically change the desired attitude angle, the desired height of the center of gravity, the gait parameters, etc. according to the terrain bumpiness.
Step 2, according to the expected attitude angle (alpha)d,βd) And the actual attitude angles (alpha, beta) of the machine body are subjected to attitude adjustment decoupling control, and the extension quantity delta p of each support phase leg i in the Z direction of the wheel leg coordinate system is generated by taking the expected attitude of the machine body as a targetiz。
The posture of the wheel-legged robot is shown in fig. 2, and the wheel-legged robot legs are divided into a left front leg LF, a left middle leg LM, a left rear leg LH, a right front leg RF, a right middle leg RM and a right rear leg RH in the clockwise direction in the figure. Wherein the RF leg is spaced from the RH by a distance l; LH leg to RM leg distance
O1～O6Is a plane with inclined posture; o is1'～O'6And adjusting the posture to a plane under the expected posture. Alpha is the roll angle of the body rotating around the X direction, beta is the pitch angle of the body rotating around the Y direction, and delta pαAnd calculating the compensation quantity of the posture of the rear RM leg in the Z direction for the roll angle of the body rotating around the X direction.
When the robot is walking in a foot-type "tripodal gait" (defining the right front leg RF, the left middle leg LM, and the right rear leg RH as one set, the left front leg LF, the left rear leg LH, and the right middle leg RM as another set, and the two sets of legs alternately become the support phase and the swing phase) over rough terrain. When i is 1,2,3, it means that the right front leg RF, the left middle leg LM, and the right rear leg RH are in the support phase; when i is 2,4,6, it means that the left front leg LF, the left rear leg LH, and the right middle leg RM are in the supporting phase.
In step 2, the actual attitude angles (α, β) of the body are obtained by detecting the actual attitude of the body at any time using an attitude sensor mounted on the body. And (3) making a difference between the actual attitude angle (alpha, beta) of the fuselage and the expected attitude angle, inputting the difference into an attitude adjustment controller, and solving the length variation of each support phase leg through an attitude decoupling geometric relationship to compensate the offset of the attitude of the fuselage.
For the electric parallel six-wheel robot realized by the Steward platform shown in FIG. 2, the delta pizThe acquisition mode is as follows:
△pβ＝l·sin(|β-βd|)/2
if the No. 1, 3 and 5 wheel legs are in the supporting phase:
when alpha is>αdAnd beta is>βd，△p1z＝-△pα/2-△pβ/2,△p3z＝△pβ/2,△p5z＝△pα/2-△pβ/2
When alpha is>αdAnd beta is<βd，△p1z＝-△pα/2-△pβ/2,△p3z＝△pβ/2,△p5z＝△pα/2+△pβ/2
When alpha is<αdAnd beta is>βd，△p1z＝△pα/2-△pβ/2,△p3z＝△pβ/2,△p5z＝△pβ/2-△pα/2
When alpha is<αdAnd beta is<βd，△p1z＝△pα/2+△pβ/2,△p3z＝-△pβ/2,△p5z＝△pβ/2-△pα/2
If the No. 2,4 and 6 wheel legs are in the supporting phase:
when alpha is>αdAnd beta is>βd，△p2z＝-△pα/2+△pβ/2,△p4z＝△pα/2+△pβ/2,△p6z＝-△pβ/2
When alpha is>αdAnd beta is<βd，△p2z＝-△pα/2-△pβ/2,△p4z＝△pα/2-△pβ/2,△p6z＝△pβ/2
When alpha is<αdAnd beta is>βd，△p2z＝△pα/2+△pβ/2,△p4z＝△pβ/2-△pα/2,△p6z＝-△pβ/2
When alpha is<αdAnd beta is<βd，△p2z＝△pα/2-△pβ/2,△p4z＝-△pα/2-△pβ/2,△p6z＝△pβ/2
Wherein l is the distance between the right front leg and the right rear leg of the wheel-leg robot, (alpha)d,βd) The expected attitude angle (alpha, beta) of the body of the wheel-foot robot is the actual attitude angle of the body.
△pizFor guiding RM leg retraction Δ piz/2, legs LF and LH overhang Δ piz/2。
Step 3, when the swing phase leg is converted into a support phase leg i by touching the ground, a force and position sensor arranged at the tail end of an electric cylinder of the wheel leg is used for obtaining a detection value, and the actual foot end contact force F of each wheel leg is solved through inverse solution calculation of kinematics and dynamics of the wheel-foot robotizAnd the Z-direction position p of the foot endiz。
Step 4, aiming at the gravity center of the robot with wheel feet in the supporting polygon, and according to the foot end contact force F of the supporting phase legizThe foot force is distributed to generate the adjustment quantity (delta p) of the horizontal position of the gravity center which can eliminate the external force and the external moment at the foot endix,△piy)。
Step 5, according to the expected gravity center height
And the actual Z-direction position p of the foot endizDelta p 'of'izThe adjustment amount of the height of the center of gravity is generated with the aim of supporting the legs to maintain the desired height of the center of gravity
As shown in fig. 3, a calculation
The preferable scheme is as follows: desired height of center of gravity of each support phase leg
And the actual Z-direction position p of the foot endizMaking difference, then averaging to obtain the gravity center height adjustment quantity
Obtained by adopting the scheme
Is a value that is the same for each support phase leg.
And 6, carrying out foot end track planning according to the gait parameters to generate foot end poses of the wheel legs, and inputting the foot end poses of the wheel legs into the wheel leg controllers for supporting the phase legs and swinging the phase legs.
Step 7, supporting the expansion amount delta p of the phase leg iizAdjustment of height of center of gravity
The sum is used as the adjustment amount of the height position of the gravity center, together with the adjustment amount of the horizontal position of the gravity center (Deltap)ix,△piy) And the wheel leg controllers are input into the supporting phase leg i together for adjusting the pose of the foot end and further performing inverse kinematics solution to the electric cylinder, so that the supporting phase leg moves at the expected gravity center height.
And the wheel leg controller of the swing phase leg calculates the control quantity of the electric cylinder according to the pose of the foot end, so as to realize the control of the swing phase leg.
The stable walking control of the wheel-foot robot is realized through the process, and the wheel-foot robot is characterized in that:
the control of the gravity center height in the steps is to realize the maximization of the movement space of the supporting leg, the height value which is decided and sent by the upper-layer system according to the environmental information is the expected gravity center height, the actual position of the leg in the vertical direction is detected to be differed when the expected gravity center height contacts the ground with the swing phase leg, the difference is used as the input of the gravity center height controller, the output quantity is input into the bottom-layer single-leg controller to be reversely solved to six electric cylinders after the calculation of the gravity center height controller, and therefore the gravity center of the robot can be always kept at the expected height, and the movement space of the supporting phase leg is maximized.
In the attitude adjustment process, the actual attitude angle is measured by the attitude sensor, the expected attitude angle is not invariable, is judged according to the external environment and is sent to the attitude controller by the upper control system. And then, the difference is made between the actual attitude angle and the expected attitude angle and is input into an attitude adjustment controller, and the length variation of each support phase leg is solved through an attitude decoupling geometric relationship to compensate the offset of the attitude of the fuselage.
Wherein, the gravity center height control refers to the height of the foot end in the Z-axis direction. The method is characterized in that the difference is made between the expected gravity center height and the actual position of a swing phase leg in the Z direction when the leg touches the ground, the actual position is used as the input of a gravity center height controller, the gravity center height of the robot is always kept at the expected height, the output quantity is input into a single-leg controller after the calculation of the gravity center height controller, and the single-leg controller is realized by reversely solving a single-leg Stewart structure to the position stretching quantity of a single electric cylinder, so that the single-leg activity space is maximized under different terrains. As shown in fig. 2 (c), this figure shows a case where the desired angle is regarded as zero degrees. In fact, the desired angle of the present invention is determined by the upper layer transmission middle layer controller, and the desired angle may be any angle depending on the environment.
The method comprises the steps of detecting foot force and foot end positions, collecting foot end force and position information not by means of a foot end multi-dimensional force/position sensor, installing force sensors and encoders at the tail ends of six electric cylinders of each leg, and calculating the force and position information of the foot end through Stewart platform kinematics and dynamics inverse solution, so that foot end external force and external moment are eliminated by using a foot force distribution controller, and the gravity center stability margin is improved.
Based on the above scheme, the present invention further provides a foot type stable walking control system for multi-information feedback electric parallel wheel-legged robot, as shown in fig. 1, the system includes: the system comprises an upper layer control system, a middle layer control system and a bottom layer control system. The upper layer control system and the middle layer control system communicate through UDP.
The upper control system mainly plays a decision-making role, obtains external environment information, inputs the environment information into the decision-making module for judgment, and autonomously sends expected attitude angles, expected gravity height, foot-type walking gait parameters and the like to the middle control system. The upper control system comprises a sensing module and a decision module.
The middle layer control system completes motion control: the device comprises an attitude adjustment controller, a touchdown detector, a foot force distribution controller, a gravity center height controller, a foot end trajectory planner, a subtracter and an adder. The foot force distribution controller solves the problem of stability margin of the gravity center of the robot and ensures that the gravity center of the robot is positioned in a supporting polygon; the attitude adjustment controller is used for ensuring that the body attitude of the robot keeps an expected attitude angle when the robot walks on a rugged terrain; the gravity center height controller is mainly used for controlling the gravity center height of the robot, so that the robot can be always kept at a desired height, and the activity space of the parallel structure supporting phase legs is maximized.
The bottom layer control system comprises a foot end force and position resolving module, a wheel leg controller of each wheel leg, an electric cylinder controller of each wheel leg, a machine body attitude sensor arranged on a wheel leg robot, and a force and position sensor arranged at the tail end of the electric cylinder of each wheel leg. In this embodiment, the wheel leg controllers of the bottom layer control system are six single-leg controllers with a Stewart-type structure, and are used for bottom layer driving.
And the perception module is used for identifying the external terrain and sending the external terrain to the decision module.
A decision-making module for determining the decision-making module,method for determining the desired attitude angle (alpha) of the body of a robot wheel-legged according to the external topographyd,βd) Desired height of center of gravity of each wheel leg
And a gait parameter; the desired attitude angle (alpha) of the fuselaged,βd) Sending to the attitude adjustment controller to adjust the desired center of gravity height
And sending the gait parameters to a subtracter and sending the gait parameters to a foot end trajectory planner.
An attitude adjustment controller for adjusting the attitude of the fuselage according to the desired attitude angle (alpha)d,βd) And the actual attitude angles (alpha, beta) of the fuselage, which are acquired by the attitude sensor of the fuselage, are subjected to attitude adjustment decoupling, and the extension quantity delta p of each support phase leg i in the Z direction of the wheel leg coordinate system is generated by taking the expected attitude of the fuselage as a targetizAnd sent to the adder. For the electric parallel six-wheel-legged robot realized by adopting the Steward platform, the posture adjustment control adopts the formula to calculate delta piz。
The foot end force and position calculating module is used for calculating the actual foot end contact force F of each wheel leg through the kinematic and dynamic inverse solution of the wheel-foot robot by utilizing the detection values of the force and position sensorsizAnd the Z-direction position p of the foot endizAnd (4) performing resolving.
A touchdown detector for converting the actual foot end contact force F of the support phase leg i after judging that the swing phase leg touchdown is converted into the support phase leg iizFoot end contact force FizSending the position p in the Z direction of the foot end of the supporting phase leg i to a foot force distribution controllerizAnd sending to the subtracter.
A foot force distribution controller for targeting the gravity center of the wheel-foot robot in the support polygon according to the foot end contact force F of the support phase legizThe foot force is distributed to generate the adjustment quantity (delta p) of the horizontal position of the gravity center which can eliminate the external force and the external moment at the foot endix,△piy) And sending the data to the wheel leg controller of the corresponding support phase.
Subtractor finding
And as a result, to the center of gravity height controller.
A center of gravity height controller for targeting the support phase leg to maintain a desired center of gravity height, based on
To produce the adjustment amount of the gravity center height
And sending the data to the adder. In a preferred embodiment, the center of gravity height controller obtains the adjustment amount of the center of gravity height
The method comprises the following steps: for supporting the legs individually
Averaging to obtain the gravity center height adjustment
The adder is to
And sending the data to the wheel leg controllers of the corresponding support phases as the adjustment quantity of the height position of the gravity center.
And the foot end track planner is used for planning the foot end track according to the gait parameters, generating the foot end pose of each wheel leg and sending the pose to the wheel leg controllers of the support phase legs and the swing phase legs.
A wheel leg controller for supporting the legs, for adjusting the height according to the height of the center of gravity
Adjustment quantity (delta p) of horizontal position of center of gravityix,△piy) Adjusting the pose of the foot end to perform inverse kinematics solutionTo the electric cylinder so that the support phase leg is maintained in motion at the desired height of the center of gravity.
And the wheel leg controller of the swing leg is used for resolving the control quantity of the electric cylinder according to the foot end pose and sending the control quantity to the corresponding electric cylinder controller.
The above embodiments only describe the design principle of the present invention, and the shapes and names of the components in the description may be different without limitation. Therefore, a person skilled in the art of the present invention can modify or substitute the technical solutions described in the foregoing embodiments; such modifications and substitutions do not depart from the spirit and scope of the present invention.
Claims (8)
1. A multi-information feedback foot type stable walking control method for an electric parallel wheel-foot robot is characterized by comprising the following steps:
determining the expected attitude angle (alpha) of the body of the wheel-foot robot according to the external topographic informationd,βd) Desired height of center of gravity of each wheel leg
And a gait parameter;
according to the desired attitude angle (alpha)d,βd) And the actual attitude angles (alpha, beta) of the machine body are subjected to attitude adjustment decoupling control, and the extension quantity delta p of each support phase leg i in the Z direction of the wheel leg coordinate system is generated by taking the expected attitude of the machine body as a targetiz；
The detection value is obtained by utilizing the force and position sensors arranged at the tail ends of the electric cylinders of the wheel legs, and the actual foot end contact force F of each wheel leg is solved through inverse solution calculation of the kinematics and dynamics of the wheel-foot robotizAnd the Z-direction position p of the foot endiz；
After the swing phase leg is converted into a support phase leg i by touching the ground, the gravity center of the robot with the wheel feet is positioned in the support polygon as the target, and the contact force F of the foot end of the support phase leg is usedizThe foot force is distributed to generate the adjustment quantity (delta p) of the horizontal position of the gravity center which can eliminate the external force and the external moment at the foot endix,△piy)；
According to desired height of center of gravity
And the actual Z-direction position p of the foot endizThe difference in gravity center height adjustment is generated with the aim of supporting the phase leg to maintain a desired gravity center height
Performing foot end trajectory planning according to the gait parameters to generate foot end poses of each wheel leg, and inputting the foot end poses into wheel leg controllers of the support phase legs and the swing phase legs;
will support the amount of expansion Δ p of the phase leg iizAdjustment of height of center of gravity
The sum is used as the adjustment amount of the height position of the gravity center, together with the adjustment amount of the horizontal position of the gravity center (Deltap)ix,△piy) The wheel leg controllers are input into the supporting phase leg i together, and are used for adjusting the pose of the foot end and further performing inverse kinematics to the electric cylinder, so that the supporting phase leg moves at the expected gravity height; and resolving the control quantity of the electric cylinder by a wheel leg controller of the swing phase leg according to the pose of the foot end, so as to realize the control of the swing phase leg.
2. The method of claim 1, wherein Δ ρ is for an electric parallel hexapod robot implemented using a Steward platformizThe acquisition mode is as follows:
if the No. 1, 3 and 5 wheel legs are in the supporting phase:
when alpha is>αdAnd beta is>βd，△p1z＝-△pα/2-△pβ/2,△p3z＝△pβ/2,△p5z＝△pα/2-△pβ/2
When alpha is>αdAnd beta is<βd，△p1z＝-△pα/2-△pβ/2,△p3z＝△pβ/2,△p5z＝△pα/2+△pβ/2
When alpha is<αdAnd beta is>βd，△p1z＝△pα/2-△pβ/2,△p3z＝△pβ/2,△p5z＝△pβ/2-△pα/2
When alpha is<αdAnd beta is<βd，△p1z＝△pα/2+△pβ/2,△p3z＝-△pβ/2,△p5z＝△pβ/2-△pα/2
If the No. 2,4 and 6 wheel legs are in the supporting phase:
when alpha is>αdAnd beta is>βd，△p2z＝-△pα/2+△pβ/2,△p4z＝△pα/2+△pβ/2,△p6z＝-△pβ/2
When alpha is>αdAnd beta is<βd，△p2z＝-△pα/2-△pβ/2,△p4z＝△pα/2-△pβ/2,△p6z＝△pβ/2
When alpha is<αdAnd beta is>βd，△p2z＝△pα/2+△pβ/2,△p4z＝△pβ/2-△pα/2,△p6z＝-△pβ/2
When alpha is<αdAnd beta is<βd，△p2z＝△pα/2-△pβ/2,△p4z＝-△pα/2-△pβ/2,△p6z＝△pβ/2
Wherein, Δ p1z～△p6zRespectively showing the stretching amount of the support legs 1-6 in the Z direction of the wheel leg coordinate system, wherein l is the distance between the right front leg and the right rear leg of the wheel leg robot,
△pβ＝l·sin(|β-βd|)/2。
3. the method of claim 1, wherein the center of gravity height adjustment amount
The acquisition mode is as follows: desired height of center of gravity of each support phase leg
And the actual Z-direction position p of the foot endizThe average of the difference is the adjustment amount of the height of the center of gravity
4. The method of claim 1, wherein the desired height of the center of gravity of each wheel leg
The same is true.
5. A multi-information feedback foot type stable walking control system of an electric parallel wheel-foot robot is characterized by comprising: the system comprises an upper layer control system, a middle layer control system and a bottom layer control system; the upper control system comprises a decision module; the middle-layer control system comprises an attitude adjustment controller, a ground contact detector, a foot force distribution controller, a gravity height controller, a foot end track planner, a subtracter and an adder; the bottom layer control system comprises a foot end force and position resolving module, a wheel leg controller of each wheel leg, an electric cylinder controller of each wheel leg, a machine body attitude sensor arranged on a wheel leg robot and a force and position sensor arranged at the tail end of the electric cylinder of each wheel leg;
the decision module is used for determining the expected attitude angle (alpha) of the body of the wheel-foot robot according to the external terraind,βd) Desired height of center of gravity of each wheel leg
And a gait parameter; the desired attitude angle (alpha) of the fuselaged,βd) Sending to the attitude adjustment controller to adjust the desired center of gravity height
Sending the gait parameters to a subtracter and sending the gait parameters to a foot end track planner;
the attitude adjustment controller is used for adjusting the attitude according to the expected attitude angle (alpha) of the fuselaged,βd) And the actual attitude angles (alpha, beta) of the fuselage, which are acquired by the attitude sensor of the fuselage, are subjected to attitude adjustment decoupling, and the extension quantity delta p of each support phase leg i in the Z direction of the wheel leg coordinate system is generated by taking the expected attitude of the fuselage as a targetizSending the data to an adder;
the foot end force and position calculating module is used for calculating the actual foot end contact force F of each wheel leg through inverse solution calculation of the kinematics and dynamics of the wheel-foot robot by utilizing the detection values of the force and position sensorsizAnd the Z-direction position p of the foot endizResolving is carried out;
the touchdown detector is used for converting the actual foot end contact force F of the support phase leg i after judging that the swing phase leg touchdown is converted into the support phase leg iizFoot end contact force FizSending the position p in the Z direction of the foot end of the supporting phase leg i to a foot force distribution controllerizSending to the subtracter;
the foot force distribution controller is used for targeting that the gravity center of the wheel-foot robot is positioned in the support polygon according to the foot end contact force F of the support phase legizThe foot force is distributed to generate the adjustment quantity (delta p) of the horizontal position of the gravity center which can eliminate the external force and the external moment at the foot endix,△piy) The data are sent to the wheel leg controllers of the corresponding supporting phases;
the subtracter calculates
The result of (1) is sent to the center of gravity height controller;
the gravity center height controller is used for supporting the phase leg maintenance periodAiming at the height of the center of gravity, according to
To produce the adjustment amount of the gravity center height
Sending the data to the adder;
the adder is to
The measured data is sent to a wheel leg controller of a corresponding support phase to be used as the adjustment quantity of the height position of the gravity center;
the foot end track planner is used for planning foot end tracks according to the gait parameters, generating foot end poses of the wheel legs and sending the foot end poses to the wheel leg controllers of the support phase legs and the swing phase legs;
the wheel leg controller for supporting the phase leg is used for adjusting the amount according to the height position of the center of gravity
Adjustment quantity (delta p) of horizontal position of center of gravityix,△piy) Adjusting the pose of the foot end, and further performing inverse kinematics to an electric cylinder to enable the support phase leg to move at the expected gravity height;
and the wheel leg controller of the swing leg is used for resolving the control quantity of the electric cylinder according to the foot end pose and sending the control quantity to the corresponding electric cylinder controller.
6. The system of claim 5, wherein for the electric parallel six-wheel robot using Steward platform, the attitude adjustment control uses the following formula to calculate Δ piz：
If the No. 1, 3 and 5 wheel legs are in the supporting phase:
when alpha is>αdAnd beta is>βd，△p1z＝-△pα/2-△pβ/2,△p3z＝△pβ/2,△p5z＝△pα/2-△pβ/2
When alpha is>αdAnd beta is<βd，△p1z＝-△pα/2-△pβ/2,△p3z＝△pβ/2,△p5z＝△pα/2+△pβ/2
When alpha is<αdAnd beta is>βd，△p1z＝△pα/2-△pβ/2,△p3z＝△pβ/2,△p5z＝△pβ/2-△pα/2
When alpha is<αdAnd beta is<βd，△p1z＝△pα/2+△pβ/2,△p3z＝-△pβ/2,△p5z＝△pβ/2-△pα/2
If the No. 2,4 and 6 wheel legs are in the supporting phase:
when alpha is>αdAnd beta is>βd，△p2z＝-△pα/2+△pβ/2,△p4z＝△pα/2+△pβ/2,△p6z＝-△pβ/2
When alpha is>αdAnd beta is<βd，△p2z＝-△pα/2-△pβ/2,△p4z＝△pα/2-△pβ/2,△p6z＝△pβ/2
When alpha is<αdAnd beta is>βd，△p2z＝△pα/2+△pβ/2,△p4z＝△pβ/2-△pα/2,△p6z＝-△pβ/2
When alpha is<αdAnd beta is<βd，△p2z＝△pα/2-△pβ/2,△p4z＝-△pα/2-△pβ/2,△p6z＝△pβ/2
Wherein, Δ p1z～△p6zRespectively showing the extension and contraction of the support legs 1-6 in the Z direction of the wheel leg coordinate system, wherein l is the wheel leg machineThe distance between the right front leg and the right rear leg of the robot;
△pβ＝l·sin(|β-βd|)/2。
7. the system for controlling the legged walking stability of the multi-information feedback electric parallel wheel-legged robot according to claim 5, wherein the gravity center height controller obtains the adjustment of the gravity center height
The method comprises the following steps: for supporting the legs individually
Averaging to obtain the gravity center height adjustment
8. The system for controlling the foot type stable walking of the multi-information feedback electric parallel wheel-legged robot according to claim 5, wherein the upper control system comprises a sensing module for recognizing external terrain and sending the external terrain to the decision module.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006315095A (en) * | 2005-05-10 | 2006-11-24 | Toyota Motor Corp | Robot and control method for it |
| DE69836765D1 (en) * | 1997-01-31 | 2007-02-08 | Honda Motor Co Ltd | CONTROL UNIT OF A LEGALLY MOVABLE ROBOT |
| KR101371756B1 (en) * | 2012-12-17 | 2014-03-12 | 현대자동차(주) | Method for controlling walking of robot |
| CN107065558A (en) * | 2017-05-05 | 2017-08-18 | 上海交通大学 | The Hexapod Robot joint angles scaling method corrected based on fuselage attitude angle |
| CN108333931A (en) * | 2018-01-25 | 2018-07-27 | 北京理工大学 | A kind of quadruped robot double-layer structure gait planning method towards rugged topography |
| CN110842921A (en) * | 2019-11-19 | 2020-02-28 | 山东大学 | Gait planning method for climbing and crossing of large-gradient terrain or high-obstacle of four-footed robot |
| CN111913490A (en) * | 2020-08-18 | 2020-11-10 | 山东大学 | Drop foot adjustment-based dynamic gait stability control method and system for quadruped robot |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103345285B (en) * | 2013-06-27 | 2015-10-28 | 山东大学 | A kind of quadruped robot remote control thereof |
| CN110697035B (en) * | 2019-09-16 | 2022-07-12 | 南京航空航天大学 | Six-degree-of-freedom independently controllable aircraft and control method thereof |
-
2021
- 2021-02-03 CN CN202110150253.7A patent/CN112965508B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE69836765D1 (en) * | 1997-01-31 | 2007-02-08 | Honda Motor Co Ltd | CONTROL UNIT OF A LEGALLY MOVABLE ROBOT |
| JP2006315095A (en) * | 2005-05-10 | 2006-11-24 | Toyota Motor Corp | Robot and control method for it |
| KR101371756B1 (en) * | 2012-12-17 | 2014-03-12 | 현대자동차(주) | Method for controlling walking of robot |
| CN107065558A (en) * | 2017-05-05 | 2017-08-18 | 上海交通大学 | The Hexapod Robot joint angles scaling method corrected based on fuselage attitude angle |
| CN108333931A (en) * | 2018-01-25 | 2018-07-27 | 北京理工大学 | A kind of quadruped robot double-layer structure gait planning method towards rugged topography |
| CN110842921A (en) * | 2019-11-19 | 2020-02-28 | 山东大学 | Gait planning method for climbing and crossing of large-gradient terrain or high-obstacle of four-footed robot |
| CN111913490A (en) * | 2020-08-18 | 2020-11-10 | 山东大学 | Drop foot adjustment-based dynamic gait stability control method and system for quadruped robot |
Non-Patent Citations (2)
| Title |
|---|
| High-Flexibility Locomotion and Whole-Torso Control for a Wheel-Legged Robot on Challenging Terrain;Wang Shoukun;《2020 IEEE International Conference on Robotics and Automation (ICRA)》;20200915;10372-10377 * |
| 电动并联六轮足机器人的运动驱动与多模态控制方法;陈志华;《机器人》;20200930;第42卷(第5期);534-549 * |
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