[0025] The present invention will be further described in detail below in conjunction with the drawings.
[0026] Such as figure 1 Shown, a tractor intelligent control method, the steps are as follows:
[0027] a) Monitor the road conditions and set the limit slip rate corresponding to the current road conditions;
[0028] b) Determine whether the real-time slip rate is less than the limit slip rate corresponding to the current road conditions;
[0029] c) If the real-time slip rate is greater than or equal to the limit slip rate corresponding to the current road conditions, then further determine whether the tractor is overloaded, if it is not overloaded, reduce the throttle opening and brake; if it is overloaded, reduce the throttle Open, brake and cut off the power output of the engine to the powertrain, and improve the agricultural machinery.
[0030] When the tractor is in an excessive slip or overload state, the above method can remove the excessive slip or overload state of the tractor, thereby preventing excessive slip of the tractor driving wheel, overload of the drive train, and the resulting damage to the drive train and tire wear .
[0031] The intelligent control system constructed according to the above method is such as Figure 4 Shown, including:
[0032] Pavement condition monitoring sensor, used to monitor the pavement condition;
[0033] Vehicle speed sensor and wheel speed sensor, used to measure vehicle speed and wheel speed;
[0034] Force sensor, used to measure the working resistance of agricultural machinery;
[0035] A controller, sampling and connecting the road surface condition monitoring sensor, force sensor, vehicle speed sensor and wheel speed sensor, output control connection actuator, the actuator includes at least throttle actuator, brake actuator, clutch actuator and agricultural implement actuator; The controller is used to determine the limit slip rate corresponding to the current road condition according to the road condition monitored by the road condition monitoring sensor, calculate the real-time slip rate according to the measured vehicle speed and wheel speed, and determine whether the real-time slip rate is less than the current road condition Corresponding limit slip rate; if the real-time slip rate is greater than or equal to the limit slip rate corresponding to the current road condition, then further judge whether the tractor is overloaded according to the working resistance of the agricultural machinery measured by the force sensor, and if it is not overloaded, control the throttle Actuator and brake actuator reduce the throttle opening and brake; if overload, control the throttle actuator and brake actuator to reduce the throttle opening, brake and control the clutch actuator to cut off the engine's power output to the powertrain , Control the implement of agricultural machinery and implement to upgrade agricultural machinery.
[0036] The vehicle speed sensor is installed on the non-driving wheel, the wheel speed sensor is installed on the driving wheel, the force sensor is installed at the connection between the hydraulic suspension mechanism and the agricultural implement, and the road condition monitoring sensor is installed on the tractor chassis. Throttle actuator includes stepper motor, throttle lever actuator. The brake actuator includes a brake solenoid valve and a brake pedal actuator. The clutch actuator includes the main clutch solenoid valve, the main clutch actuator, the PTO clutch solenoid valve, and the PTO clutch actuator. The implement mechanism of agricultural machinery includes hydraulic suspension mechanism solenoid valve and hydraulic suspension mechanism.
[0037] The controller can be constructed as a digital computer with a microprocessor or central processing unit, read-only memory ROM, random access memory RAM, high-speed clock, analog-to-digital (A/D) and digital-to-analog (D/A) circuits, and Input/output circuits and devices (I/O), as well as appropriate signal processing and buffering circuits. The control algorithm that resides in the controller or can be accessed by it can be stored in the ROM and automatically executed by the controller to implement the control process. The control algorithm is a control flow embodying the above method.
[0038] In this embodiment, the controller uses DSP, such as figure 2 , 3 , 4 shown. The minimum control system consists of reset circuit, power supply module, and JTAG interface circuit. The vehicle speed sensor signal and the wheel speed sensor signal enter the input pin of the DSP capture unit through the shaping and photoelectric isolation adjustment circuit. The capture unit detects the wheel speed and vehicle speed by detecting the level jump on the pin, and obtains the tractor's speed through calculation Real-time slip rate. The analog signal of the working resistance of agricultural machinery collected by the force sensor is input into the input pin of the A/D module of the DSP after passing through a precision resistor, a passive low-pass filter and a voltage follower circuit. The signal collected by the road condition monitoring sensor enters the DSP serial peripheral interface through the adjustment circuit, and completes the communication with the DSP in a serial communication mode. The GPIO port of the DSP is connected to the voice chip, and the voice signal is output through the speaker. The throttle lever actuator is controlled by the stepping motor driven by the ePWM module of the DSP through the drive circuit. The clutch actuator, brake pedal actuator, and hydraulic suspension mechanism all adopt electro-hydraulic control mode, and the control of the actuator is realized through the on and off of the solenoid valve driven by the ePWM of DSP.
[0039] figure 2 Since the tractor power supply voltage is 12V, and the DSP chip needs two voltages of 1.9V and 3.3V, the LM317 power conversion chip is used in the power supply circuit to convert 12V to 5V DC voltage, and then use the TPS767D301 power supply with higher voltage accuracy The chip converts the 5V voltage into 1.9V and 3.3V. The JTAG interface is used for the simulation and download of the software program, and the present invention adopts the TIDSP-XDS510 emulator. In the sensor signal acquisition circuit, the data collected by the road condition monitoring sensor is transmitted according to the RS485 protocol. In the circuit design, the MAX3430 level conversion chip is used for level conversion, and the DB9 serial port is used to complete the connection between the sensor and the controller.
[0040] image 3 In, the warning indicator is controlled by the GPIO port of the DSP, and the reset circuit is used to reset the controller. The voice circuit uses the voice chip TLV320AIC23, and a speaker is connected to the chip output terminal to remind the driver of voice operations. In the actuator drive circuit, a high-speed optocoupler 6N137 is used for signal isolation, and the freewheeling diode D uses a Schottky diode to drive the high-speed solenoid valve.
[0041] When the system is powered on, the road surface condition monitoring sensor collects road surface information, and the road surface information controller determines the limit slip rate under the current road condition; the vehicle speed sensor and wheel speed sensor collect the tractor's vehicle speed and wheel speed respectively, and obtain the tractor driving wheel through calculation The real-time slip rate of the tractor driving wheel can be calculated by the following formula:
[0042] s = rω - v rω × 100 % - - - ( 1 )
[0043] ω = 2 π × n 60 - - - ( 2 )
[0044] Among them: s is the slip rate; r is the radius of the driving wheels; v is the speed of the tractor; ω is the angular speed of the driving wheels; n is the rotational speed of the driving wheels. The controller first judges whether the real-time slip rate reaches the limit slip rate under the current road conditions. When the limit slip rate is not reached, it continues to calculate the real-time slip rate; when the limit slip rate is reached, the controller collects according to the force sensor The signal judges the working resistance of the agricultural machinery. When the working resistance of the agricultural machinery does not reach the specified value, the tractor is in a state of excessive slip and no overload. On the one hand, the controller controls the steering and speed of the stepper motor to change the position of the throttle lever. Energize the brake solenoid valve to make the brake system work. On the one hand, the indicator light is always on; when the working resistance of the agricultural machinery reaches the specified value, the tractor is in an excessive slip and overload state, and the load carried by the transmission system is too large. Cut off the power transmission between the engine and the drive train. On the one hand, the controller separates the main clutch to cut off the power transmission from the engine to the drive train, and separates the PTO clutch to cut off the power transmission from the engine to the power output shaft. The steering and speed of the stepping motor are used to change the position of the throttle lever. At the same time, the brake solenoid valve is energized to make the brake system work. On the one hand, the indicator light flashes and voice prompts are issued to guide the driver to operate.
