The equipment of a kind of synchronous real-time measurement soil profile cone index and water percentage
Technical field
The utility model relates to the equipment of a kind of measured soil cone index and water percentage, relates in particular to the equipment of a kind of synchronous real-time measurement soil profile cone index and water percentage.
Background technology
In agricultural production process, soil not only provides physical support to the growth of plant, also is the nutrition library of plant growth.The experimental results shows that soil moisture content and compactness are two most important physical parameters that influence crop growth.Water is the lifeblood that guarantees crop growth, the series reaction that is taken place in the soil, and energy is all relevant with moisture with mass exchange, and its direct relation crop yield and quality.Soil compaction is not only closely related with the break ground root system development situation of rate and plant of the germination of seed, also directly affects the migration process of soil moisture simultaneously.Soil cone index is defined as circular cone and gos deep into the long-pending suffered resistance (N/cm of unit circle poppet surface in the soil course
2), be the measurement parameter of present widely used in the world evaluation soil compaction.
Since (1980) applied statistics experimental techniques such as TOPP have disclosed quantitative relationship between soil moisture content and the soil dielectric property, soil science worker's extensive concern and attention have been caused based on the basic research of soil dielectric property.On the other hand, although soil compaction can be portrayed by measuring cone index, coupled problem makes this measurement means still be subjected to significant limitation so far in practical application between multivariate.In influencing soil moisture and compactness measuring accuracy all multifactor, people recognize that gradually the intercoupling relation between soil dielectric and the mechanical characteristic has become the main error component of determining measuring accuracy.In recent years Busscher etc. (1997, Soil ﹠amp; Tillage Research, 43:205-217), once attempted using the measurement that cone index is proofreaied and correct soil moisture content, conversely Newman and Hummel (1999, Presentation for 1999ASAE/CSAE-SCGR Annual International Meeting, Toronto, Ontario, Canada, 6,18-21) inquired into the possibility that improves the soil compaction measuring accuracy by soil moisture content.In addition, the famous TDR soil water measuring instrument Micromodultechnik of manufacturer (Available at:www.mesasystemsco.com/pdf_files/TRIME_Theory.pdf, verified2001March 27) of Germany also to the TRIME series of products of its production provided one based on the soil weight at 1.4Mg m
-3Updating formula.
Though it has been recognized that the importance and the correlativity thereof of soil compaction and soil moisture content, be independently to carry out all the time to the measurement in these two physics, make measuring process loaded down with trivial details, waste time and energy.Especially because two parameter measurements must be finished respectively, the disturbance that previous physical quantity produces soil badly influences the accuracy of a back physical quantity.
What be also pointed out that especially is, present measured soil water percentage TDR method (Time Domain Reflectometry technology commonly used, Time DomainReflectrometry) required Measuring Time is longer, need a time interval of tens of seconds between per twice measurement, can not accomplish real measuring in real time continuously, and transfer wire length had certain requirement, also there are many problems when merging with pressure transducer.
Summary of the invention
The purpose of this utility model is to overcome existing soil water measuring instrument, exist can not reach when measuring in real time continuously real continuously, and to the defective of transfer wire length requirement harshness; Thereby a kind of high-frequency resistance and stressed index of circular cone by the synchronous real-time measurement circular cone is provided, and then determines the soil cone index and the water percentage synchronous real-time measurement equipment of soil moisture content and compactness according to relevant multivariable model.
The synchronous real-time measurement soil profile cone index that the utility model provides and the equipment of water percentage, contour structures comprises as shown in Figure 1: a base 20 is provided with a head tree 15, pressure transducer 4 and depth transducer 12 on this base 20; It is characterized in that, also comprise a main erecting bed 13, these main erecting bed 13 1 sides are installed a stepper motor 5, and head tree 15 tops link to each other with sensor erecting bed 6 by main erecting bed 13 usefulness nuts, become as a whole; One gear-like guide rail 16 is set on a side of head tree 15 from top to bottom, and at least 8 pulleys 14 are installed on the sensor erecting bed 6, embrace head tree and sensor erecting bed 6 is moved up and down along the head tree direction from four direction; Main erecting bed 13 is connected with head tree 15 by pulley 14, and pulley 14 is electrically connected with stepper motor 5, and is advanced up and down along the gear-like guide rail 16 of head tree 15 by stepper motor 5 drive pulley 14; One up stroke controll block 17 is positioned at the head tree left surface, and once Stroke Control piece 18 is positioned at the bottom; One pressure transducer 4 and depth transducer 12 are installed on this sensor erecting bed 6; A hollow round bar 3 of compound sensor is installed in below the sensor erecting bed 6 by sphere link key 7; An accumulator box 25 and controller 11 are fixed in main erecting bed 13 tops, and accumulator is stepper motor 5, controller 11, sensor and compound sensor power supply; Compound sensor is electrically connected with controller 11 by signal wire 10, and measuring-signal outputs to controller 11 by the signal wire 10 of hollow oval bar 3 inside; Thereby the operation of main erecting bed is controlled in the running of described controller 11 control step motors, and three control knobs are arranged on the main panel of controller 11, is respectively applied for the main erecting bed 13 of control upwards, downward or stop motion.
In technique scheme, also be included in one pair of pedal 21 is installed on the base 20, overcome the bounce-back that the soil reacting force produces in the measuring process.
In technique scheme, also comprise a road wheel 22, this road wheel 22 is installed in a side of base 20.
In technique scheme, described controller 11 comprises: signal conditioning unit, A/D converter, CPU element, data-carrier store and data communication interface; After wherein CPU element is received the control signal of button on the controller panel, begin to send the operation of control signal drive motor, and the signal that according to circumstances begins pick-up transducers is imported, and do the rectifying and wave-filtering corresponding signal by signal conditioning unit and handle, with after the A/D converter conversion process, again data storage in storer; When resistance during greater than 500N, CPU also can send control signal to motor, the drive motor revolution.
Also comprise a PC, this PC is electrically connected with CPU element, and CPU element then can be passed to PC to data simultaneously; Data acquisition is electrically connected with multiple sensor with storer, gathers the multiple sensor signal and is transferred to PC by communication interface 24.
Described signal conditioning unit is common current rectifying and wave filtering circuit.
The length of described hollow round bar is selected according to surveying the soil profile degree of depth.
The process of utilizing equipment of the present utility model to measure is as follows:
At first press on the controller panel to knob down, the CPU of controller sends control signal to stepper motor after receiving signal, motor is advanced downwards when driving the step; When measuring beginning, compound sensor moves downwards with sensor erecting bed 6 and main erecting bed 13, controller begins sensor-lodging simultaneously, and process, store, if being connected to the communication of PC and PC and controller simultaneously is UNICOM, then controller transmits measurement data to PC simultaneously.When the sensor erecting bed is run into the down stroke piece, CPU can receive a down stroke block signal, receive behind this signal and just send the upwards control signal of operation to stepper motor, drive stepping motor is upwards advanced, and finishes the collection of sensor signal simultaneously and stops to transmit data to PC.When sensor is upwards advanced when running into the up stroke piece, CPU can receive a up stroke block signal and send the control signal that stops to stepper motor, stops the stepper motor operation, and a measurement procedure finishes.The user can be according to the requirement adjustment of the actual measurement degree of depth position of stroke piece 17,18 up and down, thereby changes the moving range of soil moisture content sensor 2.The length of described guide rail is fixed, and scope that the Stroke Control piece is controlled is the length that is less than or equal to guide rail.
Advantage of the present utility model:
The synchronous real-time measurement soil profile cone index that the utility model provides and the equipment of water percentage have: (1) merges the measurement of two kinds of different physical quantities in a sensor, and by the mathematical modeling of these two related physical quantities being improved simultaneously both measuring accuracy; Can be in the depth range of 0-50cm the real-time measured soil cone index of continuous synchronization and two important soil physics parameters of water percentage, draw vertical profile of soil cone index and water percentage; Realized the synchronous real-time measurement of soil cone index and water percentage.
(2) measured soil cone index and water percentage are the section containing parameter, and depth profiled can realize by the hollow round bar of selecting different length.
(3) speed of sensor insertion soil is constant, thereby has guaranteed the consistance to the soil cone index decipher.
The pedal that can allow the operator stand when (4) providing operation has effectively overcome the bounce-back that the soil reacting force produces in the measuring process.
(5) road wheel is installed on the head tree bottom side, does not promptly influence measurement, is convenient to the field again and moves.
(6) design by mechanically, for example the connecting portion of sensor and column is the flexible connection adopted, and sensor inserts in the soil with constant speed like this, and assurance is to the consistance of soil cone index explanation; In addition, when sensor inserts in the soil course, run into foreign matter and dodge ability; Can prevent that perhaps the soil compression that occurs is excessive in measuring process, and cause the pressure transducer overload.
(7) also have two kinds of self-protection functions in the utility model: at first, when from the resistance of soil when excessive, resistance is greater than 500N (500 newton) time, and controller will be advanced no longer downwards, but returns, and burns to prevent motor overload; Its two, the connecting portion of sensor and equipment is movable, and sensor is inserted the foreign matter of being run in the soil course, can hide the foreign matter in the soil automatically, for example stone.
(8) equipment also is provided with data acquisition and memory portion, and can connect with PC.
Description of drawings
Fig. 1 synchronous real-time measurement equipment of the present utility model three-dimensional structure diagram
Compound sensor tapering sectional view in Fig. 2 equipment of the present utility model
Main erecting bed and head tree joint portion figure in Fig. 3 equipment of the present utility model
Drawing is described as follows:
Cone-1; Soil moisture content sensor-2; Hollow oval bar-3;
Pressure transducer-4; Stepper motor-5; Erecting bed-6;
Spherical link key-7; Conehead-8; PVC insulator-9;
Signal wire-10; Controller-11; Depth transducer-12;
Main erecting bed-13; Pulley-14; Head tree-15; 5
Gear-like guide rail-16; Up stroke controll block-17; Down stroke controll block-18;
Screw-19; Base-20; Pedal-21;
Road wheel-22; Handle-23; Communication interface-24;
Battery case-25;
Embodiment
Embodiment 1, describes the utility model in detail below in conjunction with drawings and Examples.
With reference to figure 2, the compound sensor of making a present embodiment comprises: one is used to support the hollow oval bar 3 of sensor, its end has a cone, this cone is the metal circular cone of American Society of Agricultural Engineers specified standard size, and the annulus that embeds the PVC material in hollow oval bar 3 successively is insulator 9, soil moisture content sensor 2, PVC annulus insulator 9, soil moisture content sensor 2 and PVC annulus insulator 9.The cone index measuring principle is, under the driving of stepper motor 5, cone 1 inserts soil, and soil resistance passes to pressure transducer 4 by hollow oval bar 3, and converts voltage output to by it.Soil moisture content sensor 2 is embedded on the cone 1, and the mechanism of action is the edge effect of electromagnetic field.According to the Maxwell formula, the edge effect of conducting ring electromagnetic field is relevant with the specific inductive capacity of its surrounding medium, and further the relation of soil dielectric constant of pointing out according to the Topp formula again and soil moisture content can draw the initial value of tested soil moisture content.Soil moisture content sensor 2 is separated by PVC insulator 9 and conehead 8 and hollow oval bar 3, and measuring-signal outputs to device controller 11 by the signal wire 10 of hollow oval bar 3 inside.
With reference to figure 1, make the synchronous real-time measurement soil profile cone index of a present embodiment and the equipment of water percentage, the pressure transducer of buying on one market 4 is installed on sensor erecting bed 6 tops, and the hollow oval bar 3 of compound sensor is connected with sensor erecting bed 6 by spherical link key 7.Because the chain of spherical link key is connected to certain spatial degrees of freedom, guaranteed that in sensor erecting bed 6 downward traveling process when cone 1 was run into foreign matter (as stone etc.), hollow oval bar 3 had certain excursion capability, thereby avoid foreign matter, avoid the damage of foreign matter sensor.
One base 20 is provided with a head tree 15 on this base 20, the front of head tree 15 is provided with a guide rail 16 from top to bottom; The end face of head tree 15 links to each other with sensor erecting bed 6 by nut by main erecting bed 13, becomes as a whole.One depth transducer 12 and stepper motor 5 all are fixed on the main erecting bed 13, main erecting bed 13 is connected with head tree 15 by 12 pulleys 14,12 pulleys 14 are installed in respectively on the sensor erecting bed 6, the position of installing is the position of the medial surface and the head tree inclusion of sensor erecting bed, see Fig. 3 for details, embrace head tree 15 from four direction, and sensor erecting bed 6 is moved up and down along head tree 15 directions; Pulley 14 electrically connects with stepper motor 5, and is advanced up and down along the gear-like guide rail 16 in head tree 15 fronts by stepper motor 5 drivings.Depth transducer 12 adopts the potentiometer principle, causes the change of potentiometer resistance value when main erecting bed 13 moves up and down, thereby changes sensor output voltage.Stepper motor 5 drives main erecting bed 13 constant-speed operations under the control of controller 11, thereby has guaranteed the consistance to the soil cone index decipher.The top of head tree 15 left surfaces is equipped with up stroke controll block 17, and the bottom is equipped with down stroke controll block 18.Complete measuring process is as follows: when measuring beginning, compound sensor moves downwards with sensor erecting bed 6 and main erecting bed 13, when running into down stroke controll block 18, changes upwards operation of traffic direction, stops up to running into 17 operations of up stroke controll block.The user can be according to the requirement adjustment of the actual measurement degree of depth position of stroke piece 17,18 up and down, thereby changes the moving range of soil moisture content sensor 2.
Also comprise by screw 19 head tree 15 is anchored on the base 20, one pair of pedal 21 is set on base 20, when measuring, stand for the user, thus the rebound phenomena that produces owing to resistance is excessive when preventing to measure.
Also one pair of road wheel 22 can be installed on the base rear portion, during equipment work, road wheel 22 is unsettled; When mobile, make road wheel 22 walking that lands, be convenient to move by handle 23 head tree 15 that recedes.
With reference to figure 4, the controller 11 of present embodiment is installed on head tree 15 tops.There are three control knobs to be respectively applied for the main erecting bed of control upwards on its main panel, downward and stop motion.The function of controller 11 has two aspects: thus the operation of main erecting bed is controlled in the running of control step motor, and gather the multiple sensor signal and be transferred to PC by communication interface 24.Controller 11 comprises: one by common current rectifying and wave filtering circuit as signal conditioning unit;
One A/D converter is TSC7106;
One CPU element is MSP430;
One data-carrier store is FLASH628;
One data communication interface is MAX232; After wherein CPU receives the control signal of button on the panel, begin to send control signal drive motor operation, and according to circumstances begin the signal input of pick-up transducers and do corresponding signal and handle, then data storage in storer; When resistance during greater than 500N, CPU also can send control signal to motor, the drive motor revolution.
Also comprise a PC, this PC is electrically connected with CPU element, and CPU element then can be passed to PC to data simultaneously; Data acquisition is electrically connected with multiple sensor with storer, gathers the multiple sensor signal and is transferred to PC by communication interface 24.
It is stepper motor 5, device controller 11 and compound sensor power supply that this equipment adopts accumulator, and accumulator is positioned over the accumulator box 25 at controller 11 back sides during work.