FR2702552A1 - Robot for finding a target on the ground. - Google Patents

Abstract

The invention relates to a robot for searching for an objective on the ground which is composed of a spherical rolling body provided with a propelling device which intermittently advances it in independent stages of movement and a sensor device. which is activated between movement steps to locate the objective. The rolling body (2) contains a support device (4) which is automatically retracted inside the sphere during the moving steps and which can be pulled out above the surface of the sphere between two moving steps successive. The support device (4) comprises support elements (6) which are each time arranged on different diameters of the sphere of the rolling body and allow the rolling body to rest on the ground in a defined rolling position.

Description

The invention relates to a robot.

  for finding a target on the ground, composed of a spherical rolling body provided with a propulsion device which advances it intermittently by independent displacement stages and a sensor device which is activated

  between movement steps to locate the target.

  We know from documents DE-CI-31 48 169 and DE-AI-33

  362 auto-search robot systems which, like

  hicles with guided wheels, are kept in a position given in the

  of rolling or sliding support elements on the ground and are moved by

  successive stages by propulsion devices with electric motors

  Ques or reaction propulsion devices which act for a short time The use of guided robots of this type is limited because of their relatively poor all-terrain ability and their

  high energy consumption, especially on unsuitable land

cables.

  Robots of the claimed type known for example from the do-

  cument DE-AI-33 45 363 or the document DE-AI-34 00 955 are agen-

  created in freely rolling spherical bodies which, because of their great mobility and their all-terrain ability, are much better able

  overcome obstacles on the ground and travel large distances

  tances with low energy consumption These robots are mutu

  nis of a propulsion device comprising impulse thrusters

  sions integral with the sphere, with a direction of radial thrust with respect to the center of the sphere, which are actuated during the rest phases between consecutive displacement stages in such a way

  that the propellant pulse of the ignited propellant acts in the di-

  rection of the next displacement step and if possible parallel to the ground surface Such displacement as an unguided sphere however has the consequence that the robot can come to a stop in a

  any rolling position, i.e. with any point

  that from the surface of the sphere as a fulcrum on the ground, and that a complicated control and propulsion mechanism is required, for

  example in the form of tangent action thrusters

2.

  independent, to guide, during the rest phase, such a ro-

  spherical bot in a position which is optimal for the sensor device so that it locates the objective and for the propulsion device

  for the next move step.

  The objective of the invention is to arrange a robot of the type indicated in the introduction, which moves as an unguided rolling spherical body, so as to obtain with a simple construction and a low energy consumption a stable positioning of the robot

  in a rolling position defined between displacement steps

consecutive.

  The problem is solved according to the invention by the fact that the

  rolling body contains a support device which is retracted automatically-

  lying inside the sphere during the rolling movement stages and which can be taken out above the surface of the sphere between two successive movement stages, which support device comprises support elements arranged each time on different diameters of the sphere of the rolling body which provides support on the ground of the

  rolling element in a defined rolling position.

  In the robot according to the invention, thanks to the arrangement and

  the claimed arrangement of the support device, the number of positions

  possible rest positions among which the robot automatically takes-

  ment a position after removing its support device is limited to a few, preferably two or four positions, without this hindering the movement of the unguided rolling spherical body.

  thus a significant simplification of the construction and the

  request for a sensor device and a propulsion device which are optimally oriented during the rest phase, with the additional advantage that the support device operates with a

  low energy consumption and ensures, in the extended position, a

  stable and precise operation of the robot in the primary rolling position

se.

  According to an advantageous arrangement of the invention, the device

  support structure has two support elements, each with mas-

  its tipping which come out at the same time as these and which form

  in the extended position of the support device for the eccentric weights which tilt the robot into a stable rest position, in which the robot is supported on the ground by means of the two elements

  of support and a fulcrum of the surface of the sphere Of this ma-

  n the number of possible rest positions is limited to two, i.e. the surface of the sphere has only two

  predefined points which, after actuation of the support device, come

  lie in a higher position, and can therefore form the geo-polar north pole

  metric of the sphere and to which is associated each time a plane equa-

  torial which is horizontal when the north pole concerned is in position

  This limitation of the rolling position to two positions

  stable positions further simplifies construction and ordering for

  maintain an efficient sensor and propulsion system.

  According to another preferred embodiment of the invention, the support device comprises four support elements arranged at the level

  angles of a regular tetrahedron inscribed in the sphere Such an arrangement

  support sive which gives four possible rest positions with north poles uniformly distributed on the surface of the sphere, guarantees

  especially in open ground, a safe orientation of the robot in the posi-

  support concerned and, as a result of the favorable disposition of

  support points on the ground, a very stable positioning of the rolling body

  lant, the expense for a sensor and propulsion system position-

  born effectively being it is true superior to that of the mode of realization

  sation with two supporting elements, but nevertheless remaining in li-

reasonable moths.

  So that, with a simple construction, the support device in the retracted state is protected against external actions and does not cause modification of the geometry of the sphere, the support elements are provided with end elements in shape of caps which constitute a part of the surface of the sphere when the support elements are

returned.

  According to another important embodiment of the invention,

  the support device is simply arranged as a prop device

  drive by rotation which, when the supporting elements are extended, assu

  re the necessary rotation of the robot around a vertical axis passing through the north pole concerned for the location of the objective and the orientation for the next movement step According to an improvement of the invention, the support wheels which ensure rotation preferably have a profile with ribs at their circumference and, in order to further simplify construction, are advantageously formed by the cap-shaped end elements of the elements.

supporting elements.

  According to another particularly advantageous embodiment

  geux of the invention, each support element is provided with a sensor which can be taken out at the same time as the support element so that, during the rolling movement of the robot, the sensors are located in a protected position inside the surface of the sphere and, in the robot's rest position, are brought with the supporting elements, by simple mechanical means, into an active position

  exit above the surface of the sphere, with the added benefit of

  mentaire that, in the case of an arrangement following a tetrahedron of the support elements, a sensor in the extended position is each time at the north pole of the spherical body advantageous for the location of the objective In this case, it is particularly interesting , especially in the case of orientation sensors which, for efficient localization

  of the lens, must rotate around a vertical axis, to fix the diff-

  different sensors on the support wheel to obtain a driving device

  nement in simple rotation and to independently drive the support wheels so that, for the location of the objective, the support wheel located at the north pole of the sphere when the robot is in

  support position is first driven alone with the sensor attached

  above, then depending on the result of the location of the objective

  support wheels resting on the ground other support elements are

  spinning trails to rotate the entire robot around

  the vertical axis until it is precisely oriented in the direction

  displacement of the next step.

  For the fine adjustment of the support position, especially in the case of non-flat ground surfaces, the length of the support elements can

  preferably be changed independently.

  Where, as a preference, it is provided for

  propulsion device of the propellant propellant robot integral with the rolling body, as indicated in the introduction, with a direction of radial thrust relative to the center of the sphere, among which the propellant activated each time for the next propulsion step must be oriented in the rest position parallel to the ground surface in order to allow high exploitation of the movement impulse produced, with the robot according to the invention is obtained in combination with the support device described a new significant simplification of the construction and control by placing the thrusters in the region of the equatorial planes of the rolling body parallel to the surfaces of the tetrahedron or of the bearing surfaces on the ground formed by the bearing elements in the extended position With a geometric arrangement of this type of thrusters, we obtain an exact automatic orientation of

  thrusters grouped in an equatorial plane when the propellant

  then went out, without the need for an additional command

  to silence or to equip the surface of the sphere with a plurality of independent propellants distributed uniformly In order to obtain in this case a favorable distribution of the support elements and propellants on the surface of the sphere, it is advantageous to arrange the thrusters in opposition to one of the support elements and when using

  solid fuel thrusters, which cannot be used each

  each for a displacement step, to subdivide each arrangement

  propulsion in group of independent propellers arranged geo-

  metrically side by side with essentially the same direction of

  thrust, so that, in the support position, position it

  ment in rotation of the robot around the vertical axis necessary for the orientation of the thrust for the next movement step,

  can be executed with a low order expense, i.e.

  pendarnment of which propellant among the different propellants located in the equatorial plane parallel to the ground was already used during the step

  or is available for propulsion.

  The invention is described below in detail using two

  examples of construction with reference to the drawings These represent

schematically try:

  Figure 1, a robot system with its support device

  ti and with supporting elements arranged in tetrahedron; Figure 2, a robot system with two supporting elements during the rolling movement (Figure 2 a) and in the rest position

  and support with its support elements out (Figure 2 b).

  Figure 1 shows a robot 2 which is in the form of a spherical body which, during the various stages of movement, rolls unguided on the ground and which comprises a support device 4 retracted during the rolling movement , device which is formed of

  four support elements 6 arranged in the corners of a tetrahedron

  written in the sphere Each support element consists of a telescopic support rod 8 which can be taken out for example by an electric motor in the direction of a diameter of the sphere, which rod

  can be rotated around its axis for example also

  by means of an electric motor drive (not shown

  A support wheel 10 is attached to the outer end of the support rod 8, the circumference of which is provided with a rib profile and which, when the support device 4 is retracted, is in the form

  a cap-shaped sealing element which forms part of the over-

  face of the sphere The outlet length and the rotational drive of each of the support elements 6 can be controlled individually. On the underside of each support wheel 10 is fixed a sensor 12, for example a sensor of sonic, radar location,

  infrared or sensitive to laser radiation.

  The four surfaces which delimit the tetrahedron determining the geometric arrangement of the support elements 6 with respect to the rolling body 2 define four different equatorial planes or equatorial circles on the surface of the sphere, each time parallel to one of the surfaces of the tetrahedron, which are shown in dotted lines and are marked from A to D in FIG. 1 On each equatorial circle AD, a propulsion unit 14 1-14 4 is arranged in opposition each time with one of the support elements 6, c ' that is, it is located at a point on the equatorial circle which is distant by an arc length representing

  -, approximately 0.34 times the radius of the sphere with respect to a point on the surface

  face of the sphere opposite each time to one of the support elements 6, as seen clearly in FIG. 1 for the propulsion unit 14 1 The propulsion unit is located on the equatorial circle A, in opposition with the support element 6 left in the figure, that is to say is distant from the arc length S relative to the point of the surface X

  diametrically opposite to said support element 6.

  Each propulsion unit 14 is formed of a tight group

  of independent thrusters 16 with an essential thrust direction

  identical, oriented radially towards the center of the sphere.

  Among the independent propellants 16 which are in the form

  solid fuel thrusters, each time a propellant is ignited

  O O sor to execute a step of moving the spherical body 2.

  When the spherical robot 2 has come to a stop at the end of a displacement step, the support elements 6 are first removed

  simultaneously all four, one of the equatorial planes on the fig-

  re 1, the equatorial plane A then being parallel to the support surface on the ground and the support element 6 whose rod axis is perpendicular to said

  equatorial plane being in the upper position, then the mechanism of

  rotational drag associated with this support element 6 is actuated and the sensor 12 mounted on the support wheel 10 which then rotates around the axis of the rod is activated Depending on the measurement result of the sensor

  12, the rotational drive mechanisms of the other three elements

  support elements 6 resting on the ground are controlled simultaneously, so that their support wheels 10 cause a rotation of the assembly of the spherical robot 2 around the axis of the rod of the support element 6 which is in the upper position until the thrust direction of the propulsion unit 14 1 arranged in the equatorial plane A parallel to the ground coincides with the desired rolling direction of

  the next displacement step After having brought in the elements of

  then 6, the spherical robot 2 is set in motion under the action of the im

  short-lived propulsion pulse, which is produced by ignition

  an independent propellant 16 not yet used from the propulsion unit

  sion 14 1 and rolls during the next movement step This process

  sus repeats until the goal is reached or there are no more

  of independent propellant 16 usable.

  When the spherical robot has to go by itself to a given objective zone, the rolling direction is kept constant for a certain number of successive movement stages,

  for example using a compass When the target area is reached

  te, the rolling direction until the target is located is

  completed either according to a predetermined research model, or randomly, for example by suppressing the previously described rotation positioning of the spherical robot 2 using the wheels

  support 10 The control orders necessary for the different phases

  its are produced by a signal processing unit, not shown, arranged inside the sphere, with which the compass can also be associated as a direction sensor and additional sensors, approximately in the form of mercury contactors for determining the equatorial plane which is each time

parallel to the ground.

  The spherical robot according to FIG. 2, on which the elements

  elements which correspond to those of the first embodiment are designated by a reference increased by 100, differs from the first embodiment essentially by the fact that the support device 104 only comprises two support elements 106 instead of

  four, whose rods 108 with their axes are arranged on diameters

  different meters and can be removed individually As a result, when the support device 104 is extended, there are only two possible support positions, in which the rolling body 102 is maintained in a rolling position defined by the support elements 106, the corresponding support surface on the ground being located in a plane which is tangential to the surface of the sphere and touches the support wheels 110 exited at their circumference At each

  of the two possible bearing surfaces on the ground is associated with an equal plane

  torial A or B parallel to it in which, again, a unit of

  propulsion 114 1 or 114 2 composed of several independent propellers

  dants 116 is arranged in opposition to the support elements

  106 On the half sphere opposite the support elements 106, caps

  orientation sensors 112 are arranged at a point on the surface of the sphere which is situated on a radius of the sphere perpendicular to the equatorial plane A or B, which sensors, in the bearing position of the rolling body 102, can be removed above the surface of the sphere and,

  in the extended position, can be rotated by an electric motor drive

  clean body or by rotation of the entire rolling body 102 in the

  of supporting wheels 110 around the radius of the mentioned sphere serve

front of axis of rotation.

  So that the rolling body 102 always reaches one of the two defined positions even when the support elements 106 are in a position remote from the ground at the end of the rolling movement, the support elements 106 are not pulled out simultaneously but one after the other, the support wheels 110 acting by their own

  weights as masses tilting the rolling body 102 in the posi-

  defined rolling tion, in which one of the equatorial circles -

  the equatorial circle A in Figure 2 b is parallel to the ground and the cap-

  associated tor 112 is in the upper position and can therefore be

  output and activated For the rest, the design and the operating principle-

  of the spherical robot 102 are substantially identical to those of the

first example of implementation.

  Instead of placing the orientation sensors 12 or 112 in

  the top position or the position of the north pole, it can be favored

  geux with certain types of orientation sensors to have each time two diametrically opposed sensors on a parallel circle of latitude located between the different north poles of the sphere and the associated equatorial plane, the orbital movement of the sensors around the vertical axis in the support position of the spherical robot being obtained by

the support wheel drive.

Claims (9)

  1 robot for finding a target on the ground, composed of a spherical rolling body provided with a propulsion device which does so   advance intermittently in stages of independent movement   dantes and a sensor device which is activated between the movement steps to locate the objective, characterized in that the rolling body (2; 102) contains a support device (4; 104) which is retracted   automatically inside the sphere during the moving steps   cement by rolling and which can be taken out above the surface of   the sphere between two successive displacement stages, which has   support element comprises support elements (6; 106) arranged each   times on different diameters of the sphere of the rolling body allows   both the support on the ground of the rolling body in a defined rolling position. 2 robot according to claim 1, characterized in that the support device (104) comprises two support elements (106) with each time tilting masses which have come out with them   to tilt the rolling body (102) in a roll position given.   3 Robot according to claim 1, characterized in that the support device (4) comprises four support elements (6) disposed each time at the angles of a regular tetrahedron inscribed in the sphere.   4 Robot according to any one of the preceding claims.   tes, characterized in that the support elements (6; 106) are equipped with terminal elements in the form of caps which constitute a part   from the surface of the sphere when the support elements are retracted.   Robot according to any one of the preceding claims.   tes, characterized in that the support elements (6; 106) are equipped with   support wheels (10; 110) which, in the extended position, are rotated   tion to rotate the rolling body (2; 102) about a vertical axis   cal. 6 Robot according to claim 5, characterized in that the support wheels (10; 110) are provided on their circumference with profiles in the form of ribs.   7 Robot according to any one of claims 4, 5 or 6, characterized in that the terminal elements are arranged in support wheels (10; 110).   8 Robot according to any one of the preceding claims.   tes, characterized in that each support element (6) is equipped with a   sensor (12) which can be taken out with it.   9 Robot according to claim 8, characterized in that the   sensor (12) is integral in rotation with the support wheel (10) of the element   support (6) and the support wheels can be rotated tion independently.   Robot according to any one of the preceding claims.   tes, characterized in that the outlet length of the supporting elements   (6; 106) is variable and can be controlled independently.   11 Robot according to any one of the preceding claims.   in which it is intended as a propulsion unit   of propulsion to impulse integral with the rolling body with a direction   radial thrust with respect to the center of the sphere, characterized   in that the propulsion units (14 1 to 14 4; 114 1, 114 2) are available   placed in the region of the equatorial circles (A-D) of the rolling body (2; 102) parallel to the surfaces of the tetrahedron or to the bearing surfaces   on the ground formed when the device (4; 104) is in the extended position.   12 Robot according to claim 11, characterized in that the propulsion units (14) are arranged in opposition each time   relative to one of the support elements (6).   13 Robot according to claim 10 or 11, characterized in that each propulsion unit (14; 114) is composed of a group of independent propellers (16; 116) with thrust directions substantially identical. : -