CN102169649A - Demonstration teaching aid of support trafficability of sandlot model vehicle - Google Patents

Abstract

The invention discloses a demonstration teaching aid of support trafficability of sandlot model vehicle, comprising a sandlot device, a sandlot model vehicle, a computer, a data acquisition system and a drive system. The data acquisition system comprises single-chip microcomputers of No.1 to No.6 and a level conversion module. The TXD pin of the No.2 single-chip microcomputer is in electrical connection with the RXD pin of the No.3 single-chip microcomputer, the TXD pin of the No.3 single-chip microcomputer is in electrical connection with the RXD pin of the No.4 single-chip microcomputer, the TXD pin of the No.4 single-chip microcomputer is in electrical connection with the RXD pin of the No.5 single-chip microcomputer, the TXD pin of the No.5 single-chip microcomputer is in electrical connection with the RXD pin of the No.6 single-chip microcomputer, the TXD pin of the No.6 single-chip microcomputer is in electrical connection with the RXD pin of the No.1 single-chip microcomputer, the TXD pin of the No.1 single-chip microcomputer is in electrical connection with the T1IN pin of the level conversion module, and the T1OUT pin of the level conversion module is in electrical connection with the SER_IN pin of the computer serial-port. And the P1.0-P1.4 pins of the No.1 single-chip microcomputer are in electrical connection with the INT0 pins of the No.2, No.3, No.4, No.5 and No.6 single-chip microcomputers in turn.

Description

The sand ground model car supports the trafficability characteristic demonstration teaching aid

Technical field

The present invention relates to a kind of demonstration teaching aid, more particularly, the present invention relates to a kind ofly can independently monitor the displacement state, support the trafficability characteristic demonstration teaching aid by data acquisition and a kind of sand ground model car of calculating three indexs---drag coefficient, propulsive efficiency, utilization rate of electrical---of trafficability and using corresponding software interface to show the influence factor of demonstration trafficability characteristic by three indexs that will obtain.

Background technology

The control of vehicle traction power helps to improve the sand ground trafficability characteristic and the stability of four-wheel driven electric vehicle.When running car was on the road surface of low attachment coefficient, the automobile of no tractive force control driving wheel when quickening skidded easily, even caused whipping and handle the serious consequence that causes the automobile sidesway out of control.

At present, the utilization of tractive force control reaches its maturity on actual vehicle, and many vehicles have been installed traction control system.Current, field exploration oil, poisonous operating mode and to be not suitable for the problem such as exploration operation, depopulated zone experiment in human survival area outstanding day by day in modern society.Along with marching to the outer space, as mars exploration, the rapid upgrading in novel fields such as lunar mineral specimen sampling, delivery vehicle is had higher requirement, wherein sand ground is exactly the road surface of wherein a kind of worth research, and the trafficability characteristic of travelling and the Study on Stability of vehicle on sand ground remains further deeply.

Summary of the invention

Technical matters to be solved by this invention is to have overcome the problem that prior art exists, and provides a kind of sand ground model car to support the trafficability characteristic demonstration teaching aid.

For solving the problems of the technologies described above, the present invention adopts following technical scheme to realize: described sand ground model car supports the trafficability characteristic demonstration teaching aid and comprises sand ground device, computing machine, data acquisition system (DAS), drive system and telechirics.Described data acquisition system (DAS) comprises wheel speed acquisition module, speed data collection module, acceleration acquisition module, electric moter voltage acquisition module, more particularly, data acquisition system (DAS) comprises No. 5 single-chip microcomputers in level switch module that No. 1 single-chip microcomputer in the wheel speed acquisition module, No. 2 single-chip microcomputers, No. 3 single-chip microcomputers, models are MAX232, No. 4 single-chip microcomputers in the speed data collection module, the acceleration acquisition module and No. 6 single-chip microcomputers in the electric moter voltage acquisition module.

The TXD pin of No. 2 single-chip microcomputers is connected with the RXD pin electric wire of No. 3 single-chip microcomputers, the TXD pin of No. 3 single-chip microcomputers is connected with the RXD pin electric wire of No. 4 single-chip microcomputers, the TXD pin of No. 4 single-chip microcomputers is connected with the RXD pin electric wire of No. 5 single-chip microcomputers, the TXD pin of No. 5 single-chip microcomputers is connected with the RXD pin electric wire of No. 6 single-chip microcomputers, the TXD pin of No. 6 single-chip microcomputers is connected with the RXD pin electric wire of No. 1 single-chip microcomputer, the TXD pin of No. 1 single-chip microcomputer and model are that the T1IN pin electric wire of the level switch module of MAX232 is connected, and model is that the SER_IN pin electric wire of the serial ports of computers in T1OUT pin and the computing machine of level switch module of MAX232 is connected.

The P1.0 of No. 1 single-chip microcomputer～P1.4 pin is connected with the INT0 pin electric wire of No. 6 single-chip microcomputers with No. 2 single-chip microcomputers, No. 3 single-chip microcomputers, No. 4 single-chip microcomputers, No. 5 single-chip microcomputers successively.

Sand ground device described in the technical scheme is made up of husky groove, sand and anticollision sponge.Husky groove is 4 meters * wide 1 meter * high 0.5 meter cuboid groove of length of being made up of four cell walls and bottom land, between four cell walls, and all using nail to be connected between the plane on the lower surface of four cell walls and the bottom land, the material of four cell walls and bottom land all is that thickness is 2 centimetres core-board.Sand adopts the lower industrial foundry sand of the less water cut of granularity that meets People's Republic of China's industry standard-" highway earthwork test rule JTG E40-2007 " regulation, the thickness of each several part sandy soil water cut, density and soft layer is even in the husky groove, and husky groove medium sand soil thickness is 15 centimetres.The anticollision sponge adopts four sizes to be the thick 10 centimetres of hard foams of long wide 20 cm x of 20 cm x, and four sponges adopt adhesive tape to stick on the place, centre position of four cell wall inside surfaces respectively; Described wheel speed acquisition module also comprises No. 1 photoelectric encoder, No. 2 photoelectric encoders and No. 3 photoelectric encoders.No. 3 pins of No. 1 photoelectric encoder, No. 2 photoelectric encoders and No. 3 photoelectric encoders and+5V power supply+5V end electric wire is connected.No. 2 pin ground connection of No. 1 photoelectric encoder, No. 2 photoelectric encoders and No. 3 photoelectric encoders.No. 1 photoelectric encoder, No. 2 photoelectric encoders are connected with the INT1 pin electric wire of No. 3 single-chip microcomputers with No. 1 single-chip microcomputer, No. 2 single-chip microcomputers successively with No. 1 pin of No. 3 photoelectric encoders; Described acceleration acquisition module also comprises acceleration transducer, and model is No. 1 modulus conversion chip of ADC0809, and model is that the phase inverter of SN74L04N is formed.Model be ADC0809 No. 1 modulus conversion chip VREF (+) pin and LM1117 voltage stabilizing chip+3.3V output terminal electric wire is connected, the x output pin of acceleration transducer and model are that the IN2 pin electric wire of No. 1 modulus conversion chip of ADC0809 is connected, the y output pin of acceleration transducer and model are that the IN1 pin electric wire of No. 1 modulus conversion chip of ADC0809 is connected, and the z output pin of acceleration transducer and model are that the IN0 pin electric wire of No. 1 modulus conversion chip of ADC0809 is connected.Model is that the OUT1 pin of No. 1 modulus conversion chip of ADC0809 is connected with the P0.7 pin electric wire of No. 5 single-chip microcomputers, model is that the OUT2 pin of No. 1 modulus conversion chip of ADC0809 is connected with the P0.6 pin electric wire of No. 5 single-chip microcomputers, model is that the OUT3 pin of No. 1 modulus conversion chip of ADC0809 is connected with the P0.5 pin electric wire of No. 5 single-chip microcomputers, model is that the OUT4 pin of No. 1 modulus conversion chip of ADC 0809 is connected with the P0.4 pin electric wire of No. 5 single-chip microcomputers, model is that the OUT5 pin of No. 1 modulus conversion chip of ADC0809 is connected with the P0.3 pin electric wire of No. 5 single-chip microcomputers, model is that the OUT6 pin of No. 1 modulus conversion chip of ADC0809 is connected with the P0.2 pin electric wire of No. 5 single-chip microcomputers, model is that the OUT7 pin of No. 1 modulus conversion chip of ADC0809 is connected with the P0.1 pin electric wire of No. 5 single-chip microcomputers, model is that the OUT8 pin of No. 1 modulus conversion chip of ADC0809 is connected with the P0.0 pin electric wire of No. 5 single-chip microcomputers, model is that the OE pin of No. 1 modulus conversion chip of ADC0809 is connected with the P1.4 pin electric wire of No. 5 single-chip microcomputers, model is that the EOC pin of No. 1 modulus conversion chip of ADC0809 is connected with the P1.2 pin electric wire of No. 5 single-chip microcomputers, model is that the CLOCK pin of No. 1 modulus conversion chip of ADC0809 is connected with the P1.3 pin electric wire of No. 5 single-chip microcomputers, model is that the ADDA pin of No. 1 modulus conversion chip of ADC0809 is connected with the P1.5 pin electric wire of No. 5 single-chip microcomputers, model is that the ADDB pin of No. 1 modulus conversion chip of ADC0809 is connected with the P1.6 pin electric wire of No. 5 single-chip microcomputers, and model is that the ADDC pin of No. 1 modulus conversion chip of ADC0809 is connected with the P1.7 pin electric wire of No. 5 single-chip microcomputers.Model is the START of No. 1 modulus conversion chip of ADC0809 and ALE pin with model is that the 1Y pin of the phase inverter of SN74L04N is electrically connected.Model is that the 1A pin of the phase inverter of SN74L04N is connected with the P3.6 pin electric wire of No. 5 single-chip microcomputers; Described electric moter voltage acquisition module comprises that also motor, model are No. 2 modulus conversion chips of ADC0809.Model be ADC0809 No. 2 modulus conversion chips VREF (+) pin and LM7808 voltage stabilizing chip+8V output terminal electric wire is connected.Model is that the IN0 pin of No. 2 modulus conversion chips of ADC0809 is connected with the positive electrical wire of motor, and model is that the IN1 pin of No. 2 modulus conversion chips of ADC0809 is connected with the negative electrical wire of motor.Model is that No. 2 modulus conversion chips of ADC0809 and the annexation between No. 6 single-chip microcomputers and model are that No. 1 modulus conversion chip and the annexation between No. 5 single-chip microcomputers of ADC0809 is identical.Model is that START and the ALE pin and the model of No. 2 modulus conversion chips of ADC0809 is that the 2Y pin electric wire of the phase inverter of SN74L04N is connected, and model is that the 2A pin of the phase inverter of SN74L04N is electrically connected with the P3.6 pin of No. 6 single-chip microcomputers; Described drive system is that 33886 No. 1 chip and model are that 33886 No. 2 chips are formed by No. 7 single-chip microcomputers, models.Model is that the positive electrical wire of the motor in 2 OUT2 pins and the electric moter voltage acquisition module in 33886 No. 1 chip is connected.Model is that the positive electrical wire of the motor in 2 OUT2 pins and the electric moter voltage acquisition module in 33886 No. 2 chips is connected.Model is that the negative electrical wire of the motor in 2 OUT1 pins and the electric moter voltage acquisition module in 33886 No. 1 chip (6) is connected.Model is that the negative electrical wire of the motor in 2 OUT1 pins and the electric moter voltage acquisition module in 33886 No. 2 chips is connected.Model is No. 1 chip of 33886 with model is that the IN1 pin of 33886 No. 2 chips and the P2.1 pin electric wire of No. 7 single-chip microcomputers are connected, and model is No. 1 chip of 33886 with model is that the IN2 pin of 33886 No. 2 chips and the P2.2 pin electric wire of No. 7 single-chip microcomputers (16) are connected; Described telechirics comprises telepilot transmitting terminal and receiving end, and the c pin of telepilot receiving end is connected with the P of No. 7 single-chip microcomputers 3.2 pin electric wires.

Compared with prior art the invention has the beneficial effects as follows:

Automobile support trafficability characteristic control system at current comparative maturity, and on actual vehicle, used to some extent, but at present both at home and abroad in the sandy soil soil property each sandy soil parameter vehicle to be supported the research of impact effect of trafficability characteristic also less; Sand parameter for the vehicle parameter of dune buggy itself and sand ground landform is few especially to the research that influences mechanism of the support trafficability characteristic of vehicle.Sand ground model car of the present invention supports the more detailed structural parameters of having probed into sandy soil characteristic and vehicle of trafficability characteristic demonstration teaching aid dune buggy is supported the impact effect of trafficability characteristic and influences mechanism.

2. the vehicle that sand ground model car of the present invention supports sand ground control system institute research and utilization in the trafficability characteristic demonstration teaching aid is sand ground 4 wheel driven electric model car and the equipment such as husky groove built voluntarily, as the demonstration teaching aid of sand ground model car support trafficability characteristic, be this field initiative.

Description of drawings

The present invention is further illustrated below in conjunction with accompanying drawing:

Fig. 1-a is that sand ground model car of the present invention supports the axonometric projection graph that the sand ground model car structure in the trafficability characteristic demonstration teaching aid is formed;

Fig. 1-b is that sand ground model car of the present invention supports the rear view that the sand ground model car structure in the trafficability characteristic demonstration teaching aid is formed;

Fig. 1-c is that sand ground model car of the present invention supports the vertical view that the sand ground model car structure in the trafficability characteristic demonstration teaching aid is formed;

Fig. 1-d is that sand ground model car of the present invention supports the right view that the sand ground model car structure in the trafficability characteristic demonstration teaching aid is formed;

Fig. 2 is the axonometric projection graph that sand ground model car of the present invention supports the structure composition of husky groove in the trafficability characteristic demonstration teaching aid;

Fig. 3 is that model is the connection diagram of the single-chip minimum system pin of AT89S52 in the sand ground model car support trafficability characteristic demonstration teaching aid of the present invention;

Fig. 4 is the electrical schematic diagram that sand ground model car of the present invention supports power-supply system+8V mu balanced circuit in the trafficability characteristic demonstration teaching aid;

Fig. 5 is the electrical schematic diagram that sand ground model car of the present invention supports power-supply system+5V mu balanced circuit in the trafficability characteristic demonstration teaching aid;

Fig. 6 is the electrical schematic diagram that sand ground model car of the present invention supports power-supply system+3.3V mu balanced circuit in the trafficability characteristic demonstration teaching aid;

Fig. 7 is that to support No. 1～No. 4 photoelectric encoders and the model that the model in the wheel speed acquisition module and speed data collection module in the trafficability characteristic demonstration teaching aid is ZVH-4-50BM-E-26C be No. 1～No. 4 single-chip microcomputer pin connection diagrams of AT89S52 for sand ground model car of the present invention;

Fig. 8 is that sand ground model car of the present invention supports pin connection diagram between level switch module that No. 1～No. 6 single-chip microcomputer pins that the model in wheel speed acquisition module, speed data collection module, acceleration acquisition module, the electric moter voltage acquisition module in the trafficability characteristic demonstration teaching aid is AT89S52 and model be MAX232 and the serial ports of computers;

Fig. 9 is that the model that sand ground model car of the present invention supports in No. 1 single-chip microcomputer that the model in the wheel speed acquisition module in the trafficability characteristic demonstration teaching aid is AT89S52 and wheel speed acquisition module, speed data collection module, acceleration acquisition module, the electric moter voltage acquisition module is No. 2～No. 6 single-chip microcomputer pin connection diagrams of AT89S52;

Figure 10 is that sand ground model car of the present invention supports No. 5 single-chip microcomputer pins and the acceleration transducer connection diagram that the model in the acceleration acquisition module in the trafficability characteristic demonstration teaching aid is AT89S52;

Figure 11 is that sand ground model car of the present invention supports No. 6 single-chip microcomputer pins and the motor two ends connection diagram that the model in the electric moter voltage acquisition module in the trafficability characteristic demonstration teaching aid is AT89S52;

Figure 12 is that to support the model in the drive system in the trafficability characteristic demonstration teaching aid be that No. 7 single-chip microcomputer pins, the model of AT89S52 is that 33886 No. 1 chip I R1 pin, model are 33886 No. 2 chip I R2 pins and motor connection diagram for sand ground model car of the present invention;

Figure 13 is that sand ground model car of the present invention supports No. 7 single-chip microcomputer pins and the telepilot receiving end connection diagram that the model in the drive system in the trafficability characteristic demonstration teaching aid is AT89S52;

Figure 14 is that sand ground model car of the present invention supports that the model in the acceleration acquisition module and electric moter voltage acquisition module is the phase inverter pin synoptic diagram of 74LS04N in the trafficability characteristic demonstration teaching aid;

Among the figure: No. 1.1 single-chip microcomputers, No. 2.2 single-chip microcomputers, No. 3.3 single-chip microcomputers, 4.4 number single-chip microcomputer, No. 5.1 photoelectric encoders, No. 6.1 chips, 7.2 number chip, 8. motor, No. 9.3 photoelectric encoders, 10.2 number photoelectric encoder, 11. the 5th wheel mechanisms, No. 12.4 photoelectric encoders, 13. the 5th takes turns, No. 14.5 single-chip microcomputers, No. 15.6 single-chip microcomputers, 16.7 number single-chip microcomputer, 17. acceleration transducers, 18.Ni-Mh battery.

Embodiment

Below in conjunction with accompanying drawing the present invention is explained in detail:

Sand ground model car of the present invention supports the trafficability characteristic demonstration teaching aid and is made up of sand ground device, computing machine, sand ground model car, data acquisition system (DAS) (wheel speed acquisition module, speed data collection module, acceleration acquisition module, electric moter voltage acquisition module), drive system, telechirics and power-supply system.

1. sand ground device

Consult Fig. 2, the sand ground device is made up of husky groove, sand and anticollision sponge.The main effect of sand ground device is for the sand ground model car provides the sand ground road surface, simultaneously by changing sand parameter in this sand ground device, realizes that each parameter of demonstration sand supports the impact effect of trafficability characteristic and influences mechanism the sand ground model car.

1) husky groove

The husky groove that sand ground model car of the present invention supports in the trafficability characteristic demonstration teaching aid is that specification is long 4 meters * wide 1 meter * high 0.5 meter cuboid groove.Husky groove is made up of four cell walls and bottom land, between four cell walls, and all uses nail to be connected between the plane on the lower surface of four cell walls and the bottom land.Two cell wall structures that area is bigger in four cell walls are identical, and less two the cell wall structures of area are identical in four cell walls, and the material of four cell walls and bottom land all is that thickness is 2 centimetres core-board.

2) sand

According to the criteria for classification regulation of People's Republic of China's industry standard-" highway earthwork test rule JTG E40-2007 ", what the present invention used is industrial foundry sand, and the granularity of this kind sand is less, and water cut is lower, and husky groove medium sand soil thickness is 15 centimetres.

3) anticollision sponge

Anticollision sponge of the present invention is adopted hard foam, and the acting force the when cell wall of realization mitigation sand ground model car and husky groove clashes into plays the effect of protection sand ground model car.Four sponges are installed on husky groove altogether, size is thick 10 centimetres of wide 20 cm x of long 20 cm x, four sponges are installed in respectively on the inside surface of four cell walls of husky groove, every sponge sticks on by adhesive tape on the inside surface of cell wall, and the position on anticollision sea is respectively the place, centre position of four cell walls.Can both guarantee to reduce the sand ground model car like this and run through behind the husky groove bump with cell wall, can avoid in the sand ground model car is travelling the way, damaging the problem of sand ground model car again with the cell wall bump of husky groove.

2. the computing machine of built-in display interface software

The software of built-in computer display interface, the software of display interface is formed by the m file edit of matlab, as analysis of experimental data, processing platform, and draws the experimental result curve, shows experimental result.The experimental data that participates in analyzing comprises model car load, driving voltage, acceleration, four-wheel rotating speed, the speed of a motor vehicle separately, and the monitoring target of experiment (experimental result) comprises sand ground model car trafficability characteristic evaluation index drag coefficient, propulsive efficiency and the utilization rate of electrical that slippage rate and analogy are released.It is the data that the level switch module of MAX232 transmits that computing machine receives model in the data acquisition system (DAS) by serial ports of computers.

3. data acquisition system (DAS)

Consult Fig. 8, data acquisition system (DAS) is by the wheel speed acquisition module, the speed data collection module, the acceleration acquisition module, the electric moter voltage acquisition module is formed, perhaps more particularly, data acquisition system (DAS) mainly is No. 1 single-chip microcomputer 1 of AT89S52 by the model in the wheel speed acquisition module, model is No. 2 single-chip microcomputers 2 of AT89S52, model is No. 3 single-chip microcomputers 3 of AT89S52, model is the level switch module of MAX232, model in the speed data collection module is No. 4 single-chip microcomputers 4 of AT89S52, model in the acceleration acquisition module is that No. 5 single-chip microcomputers 14 of AT89S52 and No. 6 single-chip microcomputers 15 that the model in the electric moter voltage acquisition module is AT89S52 are formed.

Model is that TXD pin and the model of No. 2 single-chip microcomputers 2 of AT89S52 is that the RXD pin electric wire of No. 3 single-chip microcomputers 3 of AT89S52 is connected; Model is that TXD pin and the model of No. 3 single-chip microcomputers 3 of AT89S52 is that the RXD pin electric wire of No. 4 single-chip microcomputers 4 of AT89S52 is connected; Model is that TXD pin and the model of No. 4 single-chip microcomputers 4 of AT89S52 is that the RXD pin electric wire of No. 5 single-chip microcomputers 14 of AT89S52 is connected; Model is that TXD pin and the model of No. 5 single-chip microcomputers 14 of AT89S52 is that the RXD pin electric wire of No. 6 single-chip microcomputers 15 of AT89S52 is connected; Model is that TXD pin and the model of No. 6 single-chip microcomputers 15 of AT89S52 is that the RXD pin electric wire of No. 1 single-chip microcomputer 1 of AT89S52 is connected; Model is that TXD pin and the model of No. 1 single-chip microcomputer 1 of AT89S52 is that the T1IN pin electric wire of the level switch module of MAX232 is connected, and model is that the SER_IN pin electric wire of the serial ports of computers in T1OUT pin and the computing machine of level switch module of MAX232 is connected.

Model in the wheel speed acquisition module is No. 1 single-chip microcomputer 1 of AT89S52, model is No. 2 single-chip microcomputers 2 of AT89S52, model is No. 3 single-chip microcomputers 3 of AT89S52, model in the speed data collection module is No. 4 single-chip microcomputers 4 of AT89S52, model in the acceleration acquisition module is No. 5 single-chip microcomputers 14 of AT89S52, model in the electric moter voltage acquisition module is that the data message that No. 6 single-chip microcomputers 15 of AT89S52 will be gathered separately is delivered on the next single-chip microcomputer by serial ports, form data stream, order is successively: 15 → No. 1 single-chip microcomputers 1 of 14 → No. 6 single-chip microcomputers of 4 → No. 5 single-chip microcomputers of 3 → No. 4 single-chip microcomputers of 2 → No. 3 single-chip microcomputers of No. 2 single-chip microcomputers, and be that No. 1 single-chip microcomputer 1 of AT89S52 is connected with serial ports of computers and takes turns totally 10 numbers with one and reportedly deliver to computing machine by model finally, data are respectively: the rotary speed data of 4 wheels, 1 vehicle speed data, 3 acceleration informations, 2 electric moter voltage data.In order, coordinate mutually between single-chip microcomputer and the single-chip microcomputer successively, guarantee the transmission of data stream.Wherein model is that No. 1 single-chip microcomputer 1 of AT89S52 is a host scm, the data stream collection is initiated in responsible timing, and the control model is that No. 2 single-chip microcomputers 2, the model of AT89S52 is that No. 3 single-chip microcomputers 3, the model of AT89S52 is that No. 4 single-chip microcomputers 4, the model of AT89S52 is that No. 5 single-chip microcomputers 14 of AT89S52 are the duty (gathering and transmission) of No. 6 single-chip microcomputers 15 of AT89S52 and the data transmission between the terminal with model.

Consult Fig. 9, model is that No. 1 single-chip microcomputer 1 coordination model of AT89S52 is No. 2 single-chip microcomputers 2 of AT89S52, model is No. 3 single-chip microcomputers 3 of AT89S52, model is No. 4 single-chip microcomputers 4 of AT89S52, model is that No. 5 single-chip microcomputers 14 and the model of AT89S52 is that No. 6 single-chip microcomputers 15 of AT89S52 carry out the mode that data send and are: model is that the P1.0～P1.4 pin of No. 1 single-chip microcomputer 1 of AT89S52 is No. 2 single-chip microcomputers 2 of AT89S52 successively with model, model is No. 3 single-chip microcomputers 3 of AT89S52, model is No. 4 single-chip microcomputers 4 of AT89S52, model is that No. 5 single-chip microcomputers 14 and the model of AT89S52 is that the INT0 pin electric wire of No. 6 single-chip microcomputers 15 of AT89S52 is connected, when the sand ground model car is begun to travel by the telepilot startup, model is No. 2 single-chip microcomputers 2 of AT89S52, model is No. 3 single-chip microcomputers 3 of AT89S52, model is No. 4 single-chip microcomputers 4 of AT89S52, model is that No. 5 single-chip microcomputers 14 and the model of AT89S52 is that No. 6 single-chip microcomputers 15 of AT89S52 are opened timer, the speed of a motor vehicle of in the 10ms time is refreshed relevant variable, being deposited, wheel speed, acceleration (x, y, three of z), voltage data; Model is that No. 1 single-chip microcomputer 1 of AT89S52 is also opened timer, every 10ms time refreshes the time startup one of every 20ms when depositing speed in the variable and takes turns data acquisition, earlier making model by P1.0～P1.4 pin during startup is No. 2 single-chip microcomputers 2 of AT89S52, model is No. 3 single-chip microcomputers 3 of AT89S52, model is No. 4 single-chip microcomputers 4 of AT89S52, model is that No. 5 single-chip microcomputers 14 and the model of AT89S52 is that No. 6 single-chip microcomputers 15 of AT89S52 enter interrupt latency, at this moment each single-chip microcomputer is with the speed of synchronization, acceleration and motor 8 voltage datas are latched in the single-chip microcomputer, after the data of the upstream single-chip microcomputer that receives data stream, data that self is collected (being latched in the data in the single-chip microcomputer) and the data that receive from a last single-chip microcomputer send to next single-chip microcomputer together.Final data is sent to computing machine.So the data acquisition of sand ground model car in sand ground road traveling process finished in circulation.

1) wheel speed acquisition module

The wheel speed acquisition module be responsible for that four wheels to the sand ground model car carry out the wheel speed collection and three groups of data will gathering (the sand ground model car is monomotor 9 four-wheel drives, respectively there is a differential mechanism at the antero posterior axis place, and the rotating speed by each wheel of front and back, motor 9 and the ratio of gear of differential mechanism can draw the wheel speed of four wheels) be sent to computing machine.The wheel speed acquisition module comprises that model is that No. 1 single-chip microcomputer 1, the model of AT89S52 is that No. 2 single-chip microcomputers 2, the model of AT89S52 is that 10, No. 3 photoelectric encoders 9 of 5, No. 2 photoelectric encoders of 3, No. 1 photoelectric encoder of No. 3 single-chip microcomputers and the model of AT89S52 is the level switch module of MAX232.5, No. 2 photoelectric encoders 10 of No. 1 photoelectric encoder and No. 3 photoelectric encoders 9 and model are that No. 1 single-chip microcomputer 1, the model of AT89S52 is that No. 2 single-chip microcomputers 2 and the model of AT89S52 is that No. 3 single-chip microcomputer 3 electric wires of AT89S52 are connected and realize testing the speed.

Consult Fig. 1-a, No. 1 photoelectric encoder 5 is by screw and support aluminium flake and be fixed on the frame panel in the place ahead in the sand ground model car, and the belt pulley in No. 1 photoelectric encoder 5 rotating shafts is connected by the belt pulley on the end in the preceding differential mechanism left and right sides output terminal in belt and the sand ground model car.No. 2 photoelectric encoders 10 are by screw and support aluminium flake and be fixed on the frame panel at rear in the sand ground model car, the belt pulley in No. 2 photoelectric encoder 10 rotating shafts by in belt and the sand ground model car afterwards the belt pulley on the end in the output terminal of the differential mechanism left and right sides be connected.No. 3 photoelectric encoders 9 are by screw and support aluminium flake and be fixed on the sand ground model car frame panel, and the output terminal of motor 8 is connected by belt in No. 3 photoelectric encoder 9 rotating shafts and the sand ground model car.Model is that the level switch module of MAX232 is connected with serial ports of computers, and is that No. 1 single-chip microcomputer 1 serial port cable of AT89S52 is connected by lead and model.

Consult Fig. 7 and Fig. 8, between No. 1 single-chip microcomputer 1 and No. 1 photoelectric encoder 5, between No. 2 single-chip microcomputers 2 and No. 2 photoelectric encoders 10, annexation between No. 3 single-chip microcomputers 3 and No. 3 photoelectric encoders 9 is: No. 1 photoelectric encoder 5, No. 3 pins of No. 2 photoelectric encoders 10 and No. 3 photoelectric encoders 9 and+5V power supply+5V end electric wire is connected, No. 1 photoelectric encoder 5, No. 2 pin ground connection of No. 2 photoelectric encoders 10 and No. 3 photoelectric encoders 9, No. 1 photoelectric encoder 5, No. 1 pin (pulse output end) of No. 2 photoelectric encoders 10 and No. 3 photoelectric encoders 9 is No. 1 single-chip microcomputer 1 of AT89S52 successively with model, model is that No. 2 single-chip microcomputers 2 and the model of AT89S52 is that INT1 (P3.3) the pin electric wire of No. 3 single-chip microcomputers 3 of AT89S52 is connected.Model is that the T1OUT pin of the level switch module of MAX232 is connected with the SER_IN pin electric wire of serial ports of computers, No. 5 pin ground connection of serial ports of computers, model be MAX232 level switch module VCC pin and+5V power supply+5V end electric wire is connected, GND pin ground connection, model is that T1IN pin and the model of the level switch module of MAX232 is that TXD (P3.1) the pin electric wire of No. 1 single-chip microcomputer 1 of AT89S52 is connected, and model is No. 1 single-chip microcomputer 1 of AT89S52, model is that No. 2 single-chip microcomputers 2 and the model of AT89S52 is that No. 3 single-chip microcomputers 3 of AT89S52 are gathered photoelectric encoder 5 successively No. 1, the negative edge of No. 2 photoelectric encoders 10 and No. 3 photoelectric encoder 9 output end signals.

2) speed data collection module

The speed data collection module is responsible for the speed of a motor vehicle of sand ground model car is gathered, and is that No. 1 single-chip microcomputer 1 of AT89S52 reaches computing machine with vehicle speed data by model finally.The speed data collection module comprises that model is 4, No. 4 photoelectric encoders 12 of No. 4 single-chip microcomputers and the 5th wheel mechanism 11 of AT89S52.

Consult Fig. 1-a, the 5th wheel mechanism 11 is taken turns 13 by articulated slab, holddown spring and the 5th and is formed.Articulated slab one end is hinged on the frame panel rear end, and the other end is being fixed 12, No. 4 photoelectric encoders 12 of No. 4 photoelectric encoders and the 5th and taken turns 13 and become fixedly connected coaxially.Holddown spring is vertically fixed between articulated slab and the L-square, the lower end of the vertical panel of L-square is fixed on the rear end (being positioned at after the hinged place of articulated slab) of frame panel, vertically fixedly mount holddown spring between the horizontal wallboard in the leveling board of L-square and the articulated slab, make the 5th to take turns 13 and be attached on the sand ground ground.Guarantee in the vehicle ' process that the 5th takes turns 13 and well contact with the road surface all the time and do pure rolling, take turns 13 the revolution speed calculating speed of a motor vehicle with the 5th.Model is No. 4 single-chip microcomputers 4 of AT89S52: No. 3 pins of No. 4 photoelectric encoders 12 and+5V power supply+5V end electric wire is connected, No. 2 pin ground connection of No. 4 photoelectric encoders 12, No. 1 pin (pulse output end) and the model of No. 4 photoelectric encoders 12 are that INT1 (P3.3) the pin electric wire of No. 4 single-chip microcomputers 4 of AT89S52 is connected.

3) acceleration acquisition module

The acceleration acquisition module is No. 5 single-chip microcomputers 14 of AT89S52, the acceleration transducer 17 that model is LQ7260 by model, model is No. 1 modulus conversion chip of ADC0809, and model is that the phase inverter of SN74L04N is formed, and is responsible for the x to the sand ground model car, y, the z 3-axis acceleration is gathered.

Consult Fig. 1-a, model is that the acceleration transducer 17 of LQ7260 passes through the screw horizontal fixed in the centroid position of sand ground model car, model is that the x axle of the acceleration transducer 17 of LQ7260 is the working direction of sand ground model car, and the y axle is a left and right directions, and the z axle is a vertical direction.X, y, the acceleration output quantity of z axle is that No. 1 modulus conversion chip electric wire of ADC0809 is connected by lead and model, the acceleration digital quantity that is converted to is that No. 5 single-chip microcomputers 14 of AT89S52 record by model, and is that No. 1 single-chip microcomputer 1 of AT89S52 reaches computing machine with the 3-axis acceleration data by model finally.

Consult Figure 10, model be ADC0809 No. 1 modulus conversion chip VREF (+) pin and LM1117 voltage stabilizing chip+3.3V output terminal electric wire is connected, model is that x output pin and the model of the acceleration transducer 17 of LQ7260 is that the IN2 pin electric wire of No. 1 modulus conversion chip of ADC0809 is connected; Model is that y output pin and the model of the acceleration transducer 17 of LQ7260 is that the IN1 pin electric wire of No. 1 modulus conversion chip of ADC0809 is connected; Model is that z output pin and the model of the acceleration transducer 17 of LQ7260 is that the IN0 pin electric wire of No. 1 modulus conversion chip of ADC0809 is connected.Model is that OUT1 pin and the model of No. 1 modulus conversion chip of ADC0809 is that the P0.7 pin electric wire of No. 5 single-chip microcomputers 14 of AT89S52 is connected; Model is that OUT2 pin and the model of No. 1 modulus conversion chip of ADC0809 is that the P0.6 pin electric wire of No. 5 single-chip microcomputers 14 of AT89S52 is connected; Model is that OUT3 pin and the model of No. 1 modulus conversion chip of ADC0809 is that the P0.5 pin electric wire of No. 5 single-chip microcomputers 14 of AT89S52 is connected; Model is that OUT4 pin and the model of No. 1 modulus conversion chip of ADC0809 is that the P0.4 pin electric wire of No. 5 single-chip microcomputers 14 of AT89S52 is connected; Model is that OUT5 pin and the model of No. 1 modulus conversion chip of ADC0809 is that the P0.3 pin electric wire of No. 5 single-chip microcomputers 14 of AT89S52 is connected; Model is that OUT6 pin and the model of No. 1 modulus conversion chip of ADC0809 is that the P0.2 pin electric wire of No. 5 single-chip microcomputers 14 of AT89S52 is connected; Model is that OUT7 pin and the model of No. 1 modulus conversion chip of ADC0809 is that the P0.1 pin electric wire of No. 5 single-chip microcomputers 14 of AT89S52 is connected; Model is that OUT8 pin and the model of No. 1 modulus conversion chip of ADC0809 is that the P0.0 pin electric wire of No. 5 single-chip microcomputers 14 of AT89S52 is connected; Model is that OE pin and the model of No. 1 modulus conversion chip of ADC0809 is that the P1.4 pin electric wire of No. 5 single-chip microcomputers 14 of AT89S52 is connected; Model is that EOC pin and the model of No. 1 modulus conversion chip of ADC0809 is that the P1.2 pin electric wire of No. 5 single-chip microcomputers 14 of AT89S52 is connected; Model is that CLOCK pin and the model of No. 1 modulus conversion chip of ADC0809 is that the P1.3 pin electric wire of No. 5 single-chip microcomputers 14 of AT89S52 is connected; Model is that ADDA pin and the model of No. 1 modulus conversion chip of ADC0809 is that the P1.5 pin electric wire of No. 5 single-chip microcomputers 14 of AT89S52 is connected; Model is that ADDB pin and the model of No. 1 modulus conversion chip of ADC0809 is that the P1.6 pin electric wire of No. 5 single-chip microcomputers 14 of AT89S52 is connected; Model is that ADDC pin and the model of No. 1 modulus conversion chip of ADC0809 is that the P1.7 pin electric wire of No. 5 single-chip microcomputers 14 of AT89S52 is connected; Model is that START and the ALE pin and the model of No. 1 modulus conversion chip of ADC0809 is that the P3.6 pin of No. 5 single-chip microcomputers 14 of AT89S52 is that the phase inverter electric wire of SN74L04N is connected by model.

Consult Figure 10, Figure 14, model is the START of No. 1 modulus conversion chip of ADC0809 and ALE pin with model is that the 1Y pin of the phase inverter of SN74L04N is electrically connected; Model is that 1A pin and the model of the phase inverter of SN74L04N is that the P3.6 pin of No. 5 single-chip microcomputers 14 of AT89S52 is electrically connected.

4) electric moter voltage acquisition module

The electric moter voltage acquisition module is that No. 6 single-chip microcomputers 15, the model of AT89S52 is that No. 2 modulus conversion chips of ADC0809 are formed by motor 8, model, realizes the monitoring to motor 8 two ends input voltages.

Consult Figure 11, model be ADC0809 No. 2 modulus conversion chips VREF (+) pin and LM7808 voltage stabilizing chip+8V output terminal electric wire is connected, the positive pole of motor 8 and model are that the IN0 pin electric wire of No. 2 modulus conversion chips of ADC0809 is connected; The negative pole of motor 8 and model are that the IN1 pin electric wire of No. 2 modulus conversion chips of ADC0809 is connected; Model be No. 2 modulus conversion chips and the model of ADC0809 be between No. 6 single-chip microcomputers 15 of AT89S52 be connected and model be No. 1 modulus conversion chip and the model of ADC0809 be between No. 5 single-chip microcomputers 14 of AT89S52 be connected identical.

Consult Figure 11, Figure 14, model is that START and the ALE pin and the model of No. 2 modulus conversion chips of ADC0809 is that the 2Y pin electric wire of the phase inverter of SN74L04N is connected; Model is that 2A pin and the model of the phase inverter of SN74L04N is that the P3.6 pin of No. 6 single-chip microcomputers 15 of AT89S52 is electrically connected.

4. drive system

Drive system is that No. 7 single-chip microcomputers 16, the model of AT89S52 is 33886 No. 1 chip 6 and model is that 33886 No. 2 chips 7 are formed by model, realizes driving of sand ground model car and speed governing.

Consult Figure 12, the positive pole of the motor 8 in the electric moter voltage acquisition module and model are that 2 OUT2 pin electric wires in 33886 No. 1 chip 6 are connected; The positive pole of the motor 8 in the electric moter voltage acquisition module and model are that 2 OUT2 pin electric wires in 33886 No. 2 chips 7 are connected; The negative pole of the motor 8 in the electric moter voltage acquisition module and model are that 2 OUT1 pin electric wires in 33886 No. 1 chip 6 are connected; The negative pole of the motor 8 of electric moter voltage acquisition module and model are that 2 OUT1 pin electric wires in 33886 No. 2 chips 7 are connected; Model is No. 1 chip 6 of 33886 with model is that IN1 pin and the model of 33886 No. 2 chips 7 is that the P2.1 pin electric wire of No. 7 single-chip microcomputers 16 of AT89S52 is connected; Model is No. 1 chip 6 of 33886 with model is that IN2 pin and the model of 33886 No. 2 chips 7 is that the P2.2 pin electric wire of No. 7 single-chip microcomputers 16 of AT89S52 is connected.

5. telechirics

Telechirics comprises telepilot transmitting terminal and receiving end, and receiving end and model are that No. 7 single-chip microcomputer 16 electric wires of AT89S52 are connected, and realize the control to cycling start and parking;

Consult Figure 13, telepilot receiving end and model are the c pin that being connected between No. 7 single-chip microcomputers 16 of AT89S52 is meant the telepilot receiving end with model is that the P3.2 pin electric wire of No. 7 single-chip microcomputers 16 of AT89S52 is connected;

6. power-supply system

Power-supply system is by Ni-Mh battery 18, model is the voltage stabilizing chip of LM7808, model is that the voltage stabilizing chip of LM2940 and voltage stabilizing chip that model is LM1117 are formed, and is motor 8, No. 1 photoelectric encoder 5, No. 2 photoelectric encoders 10, No. 3 photoelectric encoders 9, No. 4 photoelectric encoders 12, model is No. 1 single-chip microcomputer 1 of AT89S52, model is No. 2 single-chip microcomputers 2 of AT89S52, model is No. 3 single-chip microcomputers 3 of AT89S52, model is No. 4 single-chip microcomputers 4 of AT89S52, model is No. 5 single-chip microcomputers 14 of AT89S52, model is No. 6 single-chip microcomputers 15 of AT89S52, model is No. 7 single-chip microcomputers 16 of AT89S52, model is No. 1 modulus conversion chip of ADC0809, model is No. 2 modulus conversion chips of ADC0809, model is 33886 No. 1 chip 6 and model is 33886 No. 2 chips 7, model provides needed power supply for acceleration transducer 17 grades of LQ7260.

Consult Fig. 4 and Figure 11, model is that No. 1 pin of the voltage stabilizing chip of LM7808 is connected with the positive electrical wire of Ni-Mh battery 18, model is No. 2 pin ground connection of the voltage stabilizing chip of LM7808, model is that No. 3 pins of the voltage stabilizing chip of LM7808 are+8V output terminal, and+8V output terminal and model are that VREF (+) the pin electric wire of No. 2 modulus conversion chips of ADC0809 is connected.

Consult Fig. 5, model is that No. 3 pins of the voltage stabilizing chip of LM2940 are connected with the positive electrical wire of Ni-Mh battery 18, model is No. 2 pin ground connection of the voltage stabilizing chip of LM2940, model is that No. 1 pin of the voltage stabilizing chip of LM2940 is+the 5V output terminal to be No. 1 photoelectric encoder 5, No. 2 photoelectric encoders 10, No. 3 photoelectric encoders 9, No. 4 photoelectric encoders 12, model is No. 1 single-chip microcomputer 1 of AT89S52, model is No. 2 single-chip microcomputers 2 of AT89S52, model is No. 3 single-chip microcomputers 3 of AT89S52, model is No. 4 single-chip microcomputers 4 of AT89S52, model is No. 5 single-chip microcomputers 14 of AT89S52, model is No. 6 single-chip microcomputers 15 of AT89S52, model provides working power for No. 7 single-chip microcomputers 16 of AT89S52 and model for acceleration transducer 17 of LQ7260 etc.

Consult Fig. 6 and Figure 10, model is that the VIN pin of the voltage stabilizing chip of LM1117 is connected with+5V input end electric wire, model is the GND pin ground connection of the voltage stabilizing chip of LM1117, model is that the OUT pin of the voltage stabilizing chip of LM1117 is+3.3V output terminal, and+3.3V output terminal and model are that VREF (+) pin and the model of No. 1 modulus conversion chip of ADC0809 is that the 3.3V pin electric wire of the acceleration transducer 17 of LQ7260 is connected.

The sand ground model car supports trafficability characteristic teaching aid demenstration method

1. lay husky groove

The thickness of each several part sandy soil water cut, density and soft layer in the husky groove is even, guarantee that four frames of husky groove all can touch sandy soil, promptly sandy soil have been full of husky groove bottom.When laying husky groove, Ying Renwei lays out the unconsolidated formation and the compacted lift of sandy soil.In order to improve experimental precision, should guarantee husky groove horizontal positioned as far as possible, do not have during little interference and rock.

2. the sand parameter constant changes sand ground model car parameter situation

Before each sand ground model car begins experiment, measure five big correlation parameters of sandy soil in the husky groove: the 1) granularity of sandy soil, 2) density of sandy soil, 3) water cut of sandy soil, 4) cone index of sandy soil, 5) specified cone index, and the record correlation parameter is in order to data processing afterwards.

3. sand ground model car parameter constant changes sand parameter situation

The sand ground dolly supports the experimental principle that the trafficability characteristic evaluation index is derived:

1) drag coefficient TC:

$\mathrm{TC}=\frac{F_d}{W}---\left(1\right)$

In the formula, F _dBe the draw bar load of sand ground dolly, W is a sand ground dolly gravity.

2) propulsive efficiency (driving efficient) TE:

$\mathrm{TE}=\frac{F_d}{T_w}\frac{u_a}{w}=\frac{F_{d}r(1-s_r)}{T_w}---\left(2\right)$

In the formula, u _aBe sand ground dolly travel speed, T _wBe the driving wheel input torque, w is a driving wheel angular velocity, and r is the driving wheel dynamic radius, s _rBe slippage rate.

3) utilization of power index E _f:

$E_f=\frac{F_d{u}_a}{E_t}---\left(3\right)$

In the formula, E _tBe the power consumption in the unit interval (watt W of unit).

4) calculating of draw bar load, driving wheel input torque

With the model simplification of car load is to act on a fixed load model on the wheel, supposes that tire and soil contact interface are that one section plane adds one section arc surface, do not consider the elastic hysteresis loss resistance and the bulldozing resistance of tire.As shown in the figure, then the elastic drive wheel is calculated as follows on soft sand ground ground:

$W=\mathrm{rb}\underset{{\mathrm{\&theta;}}_2}{\overset{{\mathrm{\&theta;}}_1}{\&Integral;}}({\mathrm{<figure-callout\; id="1"\; label="p"\; filenames="HDA0000056736210000032.png,HDA0000056736210000041.png"\; state="\{\{state\}\}">p</figure-callout>}}_1\cos \mathrm{\&theta;}+{\mathrm{\&tau;}}_1\sin \mathrm{\&theta;})\mathrm{d\&theta;}+2\mathrm{<figure-callout\; id="2"\; label="rb\; p"\; filenames="HDA0000056736210000032.png,HDA0000056736210000041.png"\; state="\{\{state\}\}">rb</figure-callout>}{p}_{}{}_2\sin {\mathrm{\&theta;}}_2---\left(4\right)$

In the formula, p ₁, τ ₁For the method on the ground connection arc surface reaches tangential stress mutually; p ₂, τ ₂For the method on the ground plane reaches tangential stress mutually; θ ₁, θ ₂Be tire ground connection angle; L is a ground plane portion length, l=2r sin θ ₂B is a tyre width.

For loose soil, the sand ground soil of this experiment usefulness for example, the stress distribution calculating formula is:

In the formula, c is the coefficient of cohesion of soil; Be angle of friction; (for the frictional property soil in this experiment, c=0); J is detrusion, and K is the detrusion modulus (husky K is about 2.5cm for pine) of soil.Pass between static sinkage z and the compressive load per unit area p is:

In the formula, k _c" adhesive aggregation " distortion modulus for soil;

" friction " distortion modulus for soil; It is long that b is into the minor face of loaded area; Z is the soil sinkage; N is the depression index.The depression at the last point of ground connection arc surface place is:

z＝r(cosθ-cosθ ₁) (7)

In formula (7) substitution formula (6), can obtain the normal stress of the last point of arc surface:

At B point place, p ₁=p ₂, therefore can obtain θ ₁, θ ₂Between relation:

$\cos {\mathrm{\&theta;}}_2=\cos {\mathrm{\&theta;}}_1-{({\mathrm{<figure-callout\; id="2"\; label="p"\; filenames="HDA0000056736210000032.png,HDA0000056736210000041.png"\; state="\{\{state\}\}">p</figure-callout>}}_2/k)}^{\frac{1}{n}}/r---\left(9\right)$

By formula (5) as can be known:

Vehicle is carried out motion analysis as can be known:

$\left\{\begin{array}{c}{j}_1\left(\mathrm{\&theta;}\right)=r[({\mathrm{\&theta;}}_1-\mathrm{\&theta;})-(1-s_r)(\sin {\mathrm{\&theta;}}_1-\sin \mathrm{\&theta;})]\\ j_2\left(\mathrm{\&theta;}\right)=j_1\left(\mathrm{\&theta;}\right)+s_{r}x\\ =r[({\mathrm{\&theta;}}_1-\mathrm{\&theta;})-(1-s_r)(\sin {\mathrm{\&theta;}}_1-\sin \mathrm{\&theta;})]\\ +s_{r}r\cos {\mathrm{\&theta;}}_2(\tan {\mathrm{\&theta;}}_2-\tan {\mathrm{\&theta;}}_1)\end{array}\right.---\left(11\right)$

With (4), (8), (9), (10), (11) this five prescriptions formula simultaneous, have 6 unknown numbers, utilize the Matlab programming can solve θ ₁, θ ₂, τ ₁, τ ₂, p ₁, p ₂These six unknown numbers.

Through deriving draw bar load F _d, driving wheel input torque T _wExpression formula as follows:

$\left\{\begin{array}{c}{F}_d=\mathrm{rb}\underset{{\mathrm{\&theta;}}_2}{\overset{{\mathrm{\&theta;}}_1}{\&Integral;}}({\mathrm{\&tau;}}_1\cos \mathrm{\&theta;}-{\mathrm{<figure-callout\; id="1"\; label="p"\; filenames="HDA0000056736210000032.png,HDA0000056736210000041.png"\; state="\{\{state\}\}">p</figure-callout>}}_1\sin \mathrm{\&theta;})\mathrm{d\&theta;}+b\underset{0}{\overset{l}{\&Integral;}}{\mathrm{\&tau;}}_2\mathrm{dx}\\ T_w=r^{2}b\underset{{\mathrm{\&theta;}}_2}{\overset{{\mathrm{\&theta;}}_1}{\&Integral;}}{\mathrm{\&tau;}}_1\mathrm{d\&theta;}+\mathrm{rb}\cos {\mathrm{\&theta;}}_2\underset{-{\mathrm{\&theta;}}_2}{\overset{{\mathrm{\&theta;}}_2}{\&Integral;}}{\mathrm{\&tau;}}_2\mathrm{d\&theta;}\end{array}\right.---\left(12\right)$

The draw bar load of sand ground dolly all is used to overcome acceleration resistance in this experiment, and available following formula is expressed:

$F_d=F_j=\mathrm{\&delta;m}\frac{\mathrm{du}}{\mathrm{dt}}=\mathrm{\&delta;ma}---\left(13\right)$

δ is a correction coefficient of rotating mass in the formula, and m is the quality of sand ground dolly, and a is the acceleration of sand ground dolly.Can calculate drag coefficient and propulsive efficiency by formula (1), formula (2) again.

For the utilization of power index,,, the utilization of power index finds the solution so need carrying out integration because this experiment is based on the data value under the acceleration situation:

$E_f=\frac{1}{T}\underset{0}{\overset{t_0}{\&Integral;}}\frac{F_d}{E_t}\mathrm{adt}---\left(14\right)$

As mentioned above, finish laggard line data in experiment and handle, draw the evaluation index that the sand ground model car supports trafficability characteristic: drag coefficient, propulsive efficiency, utilization rate of electrical.Use the unitary variant method then, only change in the factor that influences trafficability characteristic, experimentize one by one.The factor that changes comprises the driving voltage of the load of model car, the water cut of sandy soil, soft layer and compacted lift thickness and motor.Finally draw following data form and be depicted as curve by the software display interface.

Remarks: every measurement once has one group of accekeration, velocity amplitude, need utilize statistics to integrate

Remarks

Remarks: every measurement once has one group of accekeration, velocity amplitude, need utilize statistics to integrate

Remarks.

Claims (7)

1. a sand ground model car supports the trafficability characteristic demonstration teaching aid, comprise the sand ground device, computing machine, data acquisition system (DAS), drive system and telechirics, it is characterized in that, described data acquisition system (DAS) comprises the wheel speed acquisition module, the speed data collection module, the acceleration acquisition module, the electric moter voltage acquisition module, more particularly, data acquisition system (DAS) comprises No. 1 single-chip microcomputer (1) in the wheel speed acquisition module, No. 2 single-chip microcomputers (2), No. 3 single-chip microcomputers (3), model is the level switch module of MAX232, No. 4 single-chip microcomputers (4) in the speed data collection module, No. 5 single-chip microcomputers (14) in the acceleration acquisition module and No. 6 single-chip microcomputers (15) in the electric moter voltage acquisition module;

The TXD pin of No. 2 single-chip microcomputers (2) is connected with the RXD pin electric wire of No. 3 single-chip microcomputers (3), the TXD pin of No. 3 single-chip microcomputers (3) is connected with the RXD pin electric wire of No. 4 single-chip microcomputers (4), the TXD pin of No. 4 single-chip microcomputers (4) is connected with the RXD pin electric wire of No. 5 single-chip microcomputers (14), the TXD pin of No. 5 single-chip microcomputers (14) is connected with the RXD pin electric wire of No. 6 single-chip microcomputers (15), the TXD pin of No. 6 single-chip microcomputers (15) is connected with the RXD pin electric wire of No. 1 single-chip microcomputer (1), the TXD pin of No. 1 single-chip microcomputer (1) and model are that the T1IN pin electric wire of the level switch module of MAX232 is connected, and model is that the SER_IN pin electric wire of the serial ports of computers in T1OUT pin and the computing machine of level switch module of MAX232 is connected;

The P1.0 of No. 1 single-chip microcomputer (1)～P1.4 pin is connected with the INT0 pin electric wire of No. 6 single-chip microcomputers (15) with No. 2 single-chip microcomputers (2), No. 3 single-chip microcomputers (3), No. 4 single-chip microcomputers (4), No. 5 single-chip microcomputers (14) successively.

2. support the trafficability characteristic demonstration teaching aid according to the described sand ground model car of claim 1, it is characterized in that described sand ground device is made up of husky groove, sand and anticollision sponge;

Husky groove is 4 meters * wide 1 meter * high 0.5 meter cuboid groove of length of being made up of four cell walls and bottom land, between four cell walls, and all using nail to be connected between the plane on the lower surface of four cell walls and the bottom land, the material of four cell walls and bottom land all is that thickness is 2 centimetres core-board;

Sand adopts the lower industrial foundry sand of the less water cut of granularity that meets People's Republic of China's industry standard-" highway earthwork test rule JTG E40-2007 " regulation, the thickness of each several part sandy soil water cut, density and soft layer is even in the husky groove, and husky groove medium sand soil thickness is 15 centimetres;

The anticollision sponge adopts four sizes to be the thick 10 centimetres of hard foams of long wide 20 cm x of 20 cm x, and four sponges adopt adhesive tape to stick on the place, centre position of four cell wall inside surfaces respectively.

3. support the trafficability characteristic demonstration teaching aid according to the described sand ground model car of claim 1, it is characterized in that, described wheel speed acquisition module also comprises No. 1 photoelectric encoder (5), No. 2 photoelectric encoders (10) and No. 3 photoelectric encoders (9);

No. 3 pins of No. 1 photoelectric encoder (5), No. 2 photoelectric encoders (10) and No. 3 photoelectric encoders (9) and+5V power supply+5V end electric wire is connected, No. 2 pin ground connection of No. 1 photoelectric encoder (5), No. 2 photoelectric encoders (10) and No. 3 photoelectric encoders (9), No. 1 photoelectric encoder (5), No. 2 photoelectric encoders (10) are connected with the INT1 pin electric wire of No. 3 single-chip microcomputers (3) with No. 1 single-chip microcomputer (1), No. 2 single-chip microcomputers (2) successively with No. 1 pin of No. 3 photoelectric encoders (9).

4. support the trafficability characteristic demonstration teaching aid according to the described sand ground model car of claim 1, it is characterized in that, described acceleration acquisition module also comprises acceleration transducer (17), and model is No. 1 modulus conversion chip of ADC0809, and model is that the phase inverter of SN74L04N is formed;

Model be ADC0809 No. 1 modulus conversion chip VREF (+) pin and LM1117 voltage stabilizing chip+3.3V output terminal electric wire is connected, the x output pin of acceleration transducer (17) and model are that the IN2 pin electric wire of No. 1 modulus conversion chip of ADC0809 is connected, the y output pin of acceleration transducer (17) and model are that the IN1 pin electric wire of No. 1 modulus conversion chip of ADC0809 is connected, the z output pin of acceleration transducer (17) and model are that the IN0 pin electric wire of No. 1 modulus conversion chip of ADC0809 is connected, model is that the OUT1 pin of No. 1 modulus conversion chip of ADC0809 is connected with the P0.7 pin electric wire of No. 5 single-chip microcomputers (14), model is that the OUT2 pin of No. 1 modulus conversion chip of ADC0809 is connected with the P0.6 pin electric wire of No. 5 single-chip microcomputers (14), model is that the OUT3 pin of No. 1 modulus conversion chip of ADC0809 is connected with the P0.5 pin electric wire of No. 5 single-chip microcomputers (14), model is that the OUT4 pin of No. 1 modulus conversion chip of ADC0809 is connected with the P0.4 pin electric wire of No. 5 single-chip microcomputers (14), model is that the OUT5 pin of No. 1 modulus conversion chip of ADC0809 is connected with the P0.3 pin electric wire of No. 5 single-chip microcomputers (14), model is that the OUT6 pin of No. 1 modulus conversion chip of ADC0809 is connected with the P0.2 pin electric wire of No. 5 single-chip microcomputers (14), model is that the OUT7 pin of No. 1 modulus conversion chip of ADC0809 is connected with the P0.1 pin electric wire of No. 5 single-chip microcomputers (14), model is that the OUT8 pin of No. 1 modulus conversion chip of ADC0809 is connected with the P0.0 pin electric wire of No. 5 single-chip microcomputers (14), model is that the OE pin of No. 1 modulus conversion chip of ADC0809 is connected with the P1.4 pin electric wire of No. 5 single-chip microcomputers (14), model is that the EOC pin of No. 1 modulus conversion chip of ADC0809 is connected with the P1.2 pin electric wire of No. 5 single-chip microcomputers (14), model is that the CLOCK pin of No. 1 modulus conversion chip of ADC0809 is connected with the P1.3 pin electric wire of No. 5 single-chip microcomputers (14), model is that the ADDA pin of No. 1 modulus conversion chip of ADC0809 is connected with the P1.5 pin electric wire of No. 5 single-chip microcomputers (14), model is that the ADDB pin of No. 1 modulus conversion chip of ADC0809 is connected with the P1.6 pin electric wire of No. 5 single-chip microcomputers (14), model is that the ADDC pin of No. 1 modulus conversion chip of ADC0809 is connected with the P1.7 pin electric wire of No. 5 single-chip microcomputers (14), model is the START of No. 1 modulus conversion chip of ADC0809 and ALE pin with model is that the 1Y pin of the phase inverter of SN74L04N is electrically connected, and model is that the 1A pin of the phase inverter of SN74L04N is connected with the P3.6 pin electric wire of No. 5 single-chip microcomputers (14).

5. support the trafficability characteristic demonstration teaching aid according to the described sand ground model car of claim 1, it is characterized in that described electric moter voltage acquisition module comprises that also motor (8), model are No. 2 modulus conversion chips of ADC0809;

Model be ADC0809 No. 2 modulus conversion chips VREF (+) pin and LM7808 voltage stabilizing chip+8V output terminal electric wire is connected, model is that the IN0 pin of No. 2 modulus conversion chips of ADC0809 is connected with the positive electrical wire of motor (8); Model is that the IN1 pin of No. 2 modulus conversion chips of ADC0809 is connected with the negative electrical wire of motor (8); Model is that No. 2 modulus conversion chips of ADC0809 and the annexation between No. 6 single-chip microcomputers (15) and model are that No. 1 modulus conversion chip and the annexation between No. 5 single-chip microcomputers (14) of ADC0809 is identical, model is that START and the ALE pin and the model of No. 2 modulus conversion chips of ADC0809 is that the 2Y pin electric wire of the phase inverter of SN74L04N is connected, and model is that the 2A pin of the phase inverter of SN74L04N is electrically connected with the P3.6 pin of No. 6 single-chip microcomputers (15).

6. support the trafficability characteristic demonstration teaching aid according to the described sand ground model car of claim 1, it is characterized in that, described drive system is 33886 No. 1 chip (6) by No. 7 single-chip microcomputers (16), model and model is that 33886 No. 2 chips (7) are formed;

Model is that the positive electrical wire of the motor (8) in 2 OUT2 pins and the electric moter voltage acquisition module in 33886 No. 1 chip (6) is connected, model is that the positive electrical wire of the motor (8) in 2 OUT2 pins and the electric moter voltage acquisition module in 33886 No. 2 chips (7) is connected, model is that the negative electrical wire of the motor (8) in 2 OUT1 pins and the electric moter voltage acquisition module in 33886 No. 1 chip (6) is connected, model is that the negative electrical wire of the motor (8) in 2 OUT1 pins and the electric moter voltage acquisition module in 33886 No. 2 chips (7) is connected, model is 33886 No. 1 chip (6) with model is that the IN1 pin of 33886 No. 2 chips (7) and the P2.1 pin electric wire of No. 7 single-chip microcomputers (16) are connected, and model is 33886 No. 1 chip (6) with model is that the IN2 pin of 33886 No. 2 chips (7) and the P2.2 pin electric wire of No. 7 single-chip microcomputers (16) are connected.

7. support the trafficability characteristic demonstration teaching aid according to the described sand ground model car of claim 1, it is characterized in that described telechirics comprises telepilot transmitting terminal and receiving end, the c pin of telepilot receiving end is connected with the P3.2 pin electric wire of No. 7 single-chip microcomputers (16).

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