CN111439110A - Forest and fruit tea garden conveyor based on hub motor drive and control method thereof - Google Patents

Abstract

The invention discloses a forest fruit tea garden conveyer driven by a hub motor and a control method thereof. The hub motor power system of the conveyer comprises a power module, two hub motors, two front wheels and two rear wheels, and the power module connects the two In-wheel motor, two in-wheel motors are respectively integrated into the corresponding rear wheel hubs and used as the driving device of the transporter; the electronic differential control system of the transporter includes data acquisition sensors, a vehicle controller and two in-wheel motor drive controllers. The vehicle controller is connected to the data acquisition sensor and the in-wheel motor drive controller, and is used to output the corresponding differential steering strategy to the in-wheel motor drive controller according to the real-time state parameters of the vehicle; the two in-wheel motor drive controllers are respectively connected to the corresponding in-wheel motors, And control the differential steering of the vehicle according to the differential steering strategy. The conveyor of the invention has large torque, stable speed, flexible steering and light weight, and is suitable for mountain orchards with relatively narrow, complex and low terrain.

Description

Conveyor for forest, fruit and tea garden based on in-wheel motor drive and its control method

technical field

The invention relates to the technical field of electric agricultural transport machinery, in particular to a forest, fruit and tea garden transporter driven by a hub motor and a control method thereof.

Background technique

Most of the low mountain forest fruit tea gardens in southern my country lack planning, and most economic crops such as fruit trees grow in areas where it is difficult to form a relatively complete transportation network, and the site conditions are poor. However, the conventional agricultural transporter has the characteristics of wide wheelbase, large volume and weight, high cost and low vehicle use economy, which makes it difficult to popularize and use it in the low and gentle mountain forest, fruit and tea gardens. Difficulties. On the other hand, the management process of planting, fertilizing and picking crops in mountain forest, fruit and tea gardens requires a lot of transportation labor, and labor costs rise. From this point of view, it is of great significance to realize the mechanization of the transportation operation of the low and gentle mountain forest, fruit and tea gardens and the adaptation of the terrain of the transport aircraft.

With the gradual prominence of the mechanization of the transportation of mountain forests, fruit and tea gardens, the transportation machinery for mountain forests, fruit and tea gardens has been paid more and more attention. Wu Weibin from South China Agricultural University and others have trial-produced the first generation of traditional fuel-engine-driven four-wheeled transporters suitable for the transportation of forest, fruit, and tea gardens in low and gentle mountains in southern China. Driving on a narrow road in Linguo Tea Garden.

Due to the increasingly serious problems of energy consumption and environmental pollution, the use of electric-driven agricultural transport aircraft is both energy-saving and environmentally friendly, so it has received more and more attention. Subsequently, Wu Weibin and others from South China Agricultural University carried out the development of the second-generation transporter based on the fuel engine-driven transporter, that is, the centralized motor-driven transporter for the low and gentle mountain forest, fruit and tea gardens. However, this conveyor has shortcomings: the transmission chain is long and the transmission efficiency is low. Usually, a motor with high speed and high power is required, and the performance requirements of the motor are high. In addition, the transport aircraft is large in size and weight, has poor start-up acceleration and passability, and has poor ability to climb and climb obstacles.

Japan's NTN company launched a new generation of in-wheel motor four-wheel drive new electric vehicle Q'mo at the Beijing Auto Show. The use of four-wheel independent control system makes the vehicle maneuverability extremely strong, but the electric vehicle still has shortcomings: high cost, The applicable area is limited, and it is not suitable for the operation of mountain forest, fruit and tea gardens.

Zhang Jianbao of Hebei United University designed a miniature logistics electric vehicle driven by in-wheel motor, which is light in structure, low in energy consumption, and environmentally friendly. It is also only suitable for the handling of low-weight objects. It is limited in use in agricultural areas and is not suitable for use. Disadvantages of working in mountain forest, fruit and tea gardens.

It can be seen that the existing mechanical equipment as above still has shortcomings such as poor endurance performance, large size, not light and flexible enough, high cost, limited objects and operating areas, etc. Therefore, it is necessary to develop a forest that can overcome the above defects. Orchard transporter.

SUMMARY OF THE INVENTION

The first object of the present invention is to overcome the shortcomings and deficiencies of the prior art, and to provide a forest fruit tea garden conveyor driven by a hub motor, which has large torque, stable speed, flexible steering, low pollution, light weight and low cost , suitable for mountain orchards with narrow, complex and low terrain.

The second object of the present invention is to provide a method for controlling a forest fruit and tea orchard conveyor driven by a hub motor, which can flexibly control the transportation operation of the conveyor in a mountainous orchard with relatively narrow, complex and low terrain.

The first object of the present invention is achieved by the following technical solutions: a forest fruit tea garden transporter driven by a hub motor, comprising: a vehicle frame, a vehicle body, a console, a limiter with an accelerator pedal and a brake pedal arranged on the vehicle frame parking system, steering system with steering wheel and in-wheel motor power system and electronic differential control system, wherein,

The hub motor power system includes a power module, two permanent magnet brushless torque hub motors, two agricultural mountain front wheels located on the left and right sides of the frame and two agricultural mountain rear wheels located behind the front wheels. The power module is connected Two in-wheel motors, which are respectively integrated into the corresponding rear wheel hubs and used as the driving device of the transporter;

The electronic differential control system includes a data acquisition sensor, a vehicle controller and two in-wheel motor drive controllers. The vehicle controller is connected to the data acquisition sensor and the in-wheel motor drive controller to drive the in-wheel motor according to the real-time state parameters of the vehicle. The controller outputs the corresponding differential steering strategy; the real-time state parameters of the vehicle include the hub motor speed, steering wheel angle, accelerator pedal stroke and brake pedal stroke collected by the data acquisition sensor, and the vehicle controller calculated based on the hub motor speed. speed;

The two in-wheel motor drive controllers are respectively connected to the corresponding in-wheel motors, and control the differential steering of the entire vehicle according to the differential steering strategy.

Preferably, the data acquisition sensor includes a steering wheel angle position sensor, a rotational speed sensor, an acceleration signal sensor and a braking signal sensor, wherein,

The steering wheel angle position sensor is installed on the rotation shaft of the steering wheel to determine whether the steering wheel is rotated and to detect the size of its rotation angle; the rotational speed sensor is installed in the hub motor in the rear wheel to detect the rotational speed of the hub motor; the acceleration signal sensor is installed on the accelerator pedal , used to detect the stroke of the accelerator pedal; the brake signal sensor is installed on the brake pedal to detect the stroke of the brake pedal.

Preferably, the frame of the transporter is a bridge-type structure bridged over the front and rear wheels;

The transporter is also provided with a leaf spring type non-independent suspension frame and a leaf spring fixing bracket under the frame, the leaf spring type non-independent suspension frame is located between the frame and the axle connecting the two rear wheels, and the leaf spring fixing bracket is wrapped around. The lifting axle is connected to the bottom of the frame, and is used to support the axle and the leaf spring type non-independent suspension frame upward; the hub motor is fixed to the axle through fixing bolts.

Further, the leaf spring type non-independent suspension frame is formed by stacking a plurality of steel plates with unequal lengths and unequal curvatures. The curvature of the steel plate is smaller than the curvature of the steel plate stacked above, and the length of the steel plate stacked below is smaller than the length of the steel plate stacked above.

Further, each leaf spring type dependent suspension frame corresponds to two leaf spring fixing brackets, and the two leaf spring fixing brackets jointly clamp the leaf spring type dependent suspension frame, so that the leaf spring type dependent suspension frame is limited to between the frame and the axle.

Preferably, the in-wheel motor adopts a low-speed outer rotor motor, and the in-wheel motor is equipped with a reducer with a fixed transmission ratio and a brake caliper for braking;

The rotational speed sensor is a Hall sensor arranged inside the wheel hub motor; the steering wheel angle position sensor, the acceleration signal sensor and the braking signal sensor are all resistive sensors.

Preferably, the vehicle controller has an AD conversion module, an IO signal module and a main controller, and the AD conversion module is connected to the main controller, and sends the in-wheel motor speed, steering wheel angle, acceleration, etc. in the real-time state parameter information of the vehicle to the main controller. Pedal stroke and brake pedal stroke;

The IO signal module is connected to the main controller, and sends the key start signal and gear selection signal input from the control panel of the transporter to the main controller;

The main controller connects the two in-wheel motor drive controllers through the IO signal module, and sends the corresponding PWM output signal for controlling the speed of the in-wheel motor to the two in-wheel motor drive controllers; the main controller connects the power module through the IO signal module, And send a start control signal to the power module.

Further, the power module includes a lead-storage power supply, a DC/DC converter and a contactor, and the lead-storage power supply is connected to the DC/DC converter and converted into a 5V power supply connected to the main controller through the DC/DC converter; The contactor connects the two in-wheel motor drive controllers, and supplies power to the two in-wheel motor drive controllers when the contactor receives a start control signal.

The second object of the present invention is achieved through the following technical solutions: a method for controlling a fruit and tea garden conveyer driven by a hub motor, wherein the fruit and tea garden conveyer is the first object of the present invention driven by an in-wheel motor. The tea garden transporter, the control method includes the following steps:

S1. The vehicle controller of the electronic differential control system receives the key start signal and gear selection signal from the transporter console;

S2. The vehicle controller receives the wheel motor speed, steering wheel angle, accelerator pedal stroke and brake pedal stroke collected in real time by the data acquisition sensor, calculates the vehicle speed according to the wheel motor rotation speed, and then formulates two wheel hubs according to the real-time state parameter information of the vehicle. Differential steering strategy of the motor, and transmit the differential steering strategy to the in-wheel motor drive controller;

S3. The two in-wheel motor drive controllers control the in-wheel motors of the in-wheel motor power system according to the differential steering strategy, so as to control the differential steering of the whole vehicle.

Preferably, the processing process of the vehicle controller is as follows:

S21. When the electronic differential control system is working normally, the IO signal module receives the key start signal and the gear selection signal and inputs them into the main controller, and the main controller begins to initialize: its internal ADC sampling function module, timer The module and the serial communication module are initialized, start the internal program, and the timer module distributes the clock;

At the same time, the start control signal is sent to the power module through the IO signal module, so that the power module can supply power to the two in-wheel motor drive controllers;

S22. The AD conversion module receives the steering wheel angle collected by the steering wheel angle position sensor, the hub motor speed collected by the rotational speed sensor, the accelerator pedal stroke collected by the acceleration signal sensor, and the brake pedal stroke collected by the brake signal sensor, and converts these The analog signal is converted into a digital signal and input to the main controller;

S23. After receiving the speed signal of the hub motor, the stroke of the accelerator pedal and the stroke of the brake pedal, the main controller calculates the current vehicle speed and the actual speed required by the hub motors of the left and right rear wheels, and outputs the PWM duty cycle to the hub motor drive controller To control the current speed of the hub motor, and then control the speed of the transport locomotive;

In this process, after starting the ADC program in the ADC sampling function module to collect the information of each sensor, it stops the timing operation of the timer module, and then enters the interrupt program to analyze the information of each sensor:

If the sensor information indicates that the transporter is not turning, then the steps after the timing interruption will not be performed, and the AD conversion of each sensor information will continue;

If the sensor information indicates that the transporter is about to turn, execute the following steering procedure after timing interruption, specifically: after receiving the steering wheel angle signal, the main controller performs active differential calculation according to the steering wheel angle signal, and sends the signal to the two wheel hub motors through the IO signal module. The drive controller sends PWM output signals with different duty cycles;

Control the hub motor according to the differential steering strategy, specifically: the current speed of the rear wheel hub motor located on the outside of the curve remains unchanged, and the rear wheel hub motor located on the inner side of the curve reduces the speed according to the actual required speed difference.

Compared with the prior art, the present invention has the following advantages and effects:

(1) The present invention applies the in-wheel motor to the agricultural transporter. The in-wheel motor does not require any transmission system, and the torque output by the motor rotor directly acts on the wheel, which saves the complex and heavy part of the transmission system of the traditional automobile. The structure is more lightweight and can be improved. Transmission efficiency, energy saving, and low cost, which meet the requirements of modern agricultural mechanization; at the same time, the transporter adopts in-wheel motors, which can reduce the turning radius, which is conducive to improving flexibility, and is more suitable for mountain orchards with narrow, complex, and gentle terrain. transport work.

(2) The present invention is based on the in-wheel motor-driven forest fruit tea garden transporter which adopts in-wheel motor power system and electronic differential control system. The two in-wheel motors have active differential drive capability, which can independently control the acceleration and deceleration of the in-wheel motors on both sides and effectively maintain the vehicle. The stability of cornering makes it possible to carry goods safely and stably in the Linguo Tea Garden, which improves production efficiency; and, since the in-wheel motor does not require any transmission system, compared with the traditional transporter using the transmission system, under the condition of equal battery capacity, The transport aircraft of the invention has stronger air resistance and no emissions.

(3) The transporter of the present invention utilizes the electronic differential speed control system to generate the differential steering strategy executed by the in-wheel motor drive controller, and replaces the traditional mechanical differential speed with the electronic differential speed control technology to realize the pure rolling of the inner and outer wheels at different rotational speeds during turning. The differential speed control of the two in-wheel motors is effectively performed, which improves the stability of the vehicle when the vehicle is cornering, and is conducive to carrying crops and other items more efficiently and safely.

(4) The transporter of the present invention is provided with a leaf spring type non-independent suspension frame and a leaf spring fixing bracket under the frame, which can play the role of shock absorption and guidance, improve the stability and safety of the transporter, and save the traditional The guide device and shock absorber make the structure of the conveyor simpler.

Description of drawings

FIG. 1 is a top view of the forest fruit tea garden conveyor driven by the in-wheel motor of the present invention.

FIG. 2 is a schematic structural diagram of the bottom of the conveyor of FIG. 1 .

Figure 3(a) is a schematic diagram of an in-wheel motor.

Fig. 3(b) is a schematic diagram of the in-wheel motor from another perspective.

4 is a cross-sectional view of the in-wheel motor mounted on the rear wheel.

FIG. 5 is a schematic diagram of the electronic differential control system of the conveyor of FIG. 1 .

FIG. 6 is a flowchart of a control method of the conveyor of FIG. 1 .

FIG. 7 is a flow chart of the main loop of the main controller program in the electronic differential control system.

Detailed ways

The present invention will be described in further detail below with reference to the embodiments and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

Example

This embodiment discloses a fruit and tea garden transporter driven by in-wheel motors, as shown in Figures 1 and 2, comprising: a frame 2, a body, a console, a limited parking system, and a steering system arranged on the frame As well as in-wheel motor power system and electronic differential control system.

The vehicle body is provided with a seat 1 on the frame, and a front light 13 is provided at the front of the vehicle. The console includes an instrument panel 4, a key socket and a manual control button for gear selection, and the console is located in front of the seat 1 of the vehicle body.

The limited parking system includes an accelerator pedal 5, a parking stopper 6, a reverse gear push rod 7 and a brake pedal 8, the parking stopper and the reverse gear push rod are arranged beside the seat, and the accelerator pedal and the brake pedal are arranged in front of the seat.

The steering system consists of a steering gear fixed on the frame and a steering transmission mechanism. The steering gear includes a steering wheel 3, a steering shaft, a steering worm and a steering rocker shaft located in front of the seat. The steering transmission mechanism includes a steering rocker arm and a steering pull rod. , steering knuckle arm, left and right steering trapezoidal arm and steering tie rod.

The hub motor power system includes a power module, two permanent magnet brushless torque hub motors 9, two agricultural mountain front wheels 15 located on the left and right sides of the frame, and two agricultural mountain rear wheels 14 located behind the front wheels. The power module is connected to two in-wheel motors, and the two in-wheel motors are respectively integrated into the corresponding rear wheel hubs 142 to rotate synchronously with the rear wheels and serve as the driving device of the transporter. As shown in Figures 3(a) and 3(b), the connecting shaft 16 of the in-wheel motor is used to electrically connect the relevant on-board circuits, and the bolt holes 17 of the in-wheel motor are used to cooperate with the fixing bolts, so that the in-wheel motor is fixed to connect the two Axle 18 for the rear wheel.

The forest fruit tea garden conveyor of this embodiment integrates the wheel hub motor and the agricultural mountain type rear tire, and cancels the mechanical transmission parts such as the clutch, the transmission shaft, the transmission and the main reducer, which not only simplifies the mechanical part, improves the transmission efficiency, but also eliminates the need for mechanical transmission. It can reduce the weight of the whole vehicle and improve the economy and applicability.

In this embodiment, the in-wheel motor adopts a low-speed outer rotor motor, and FIG. 4 shows the internal structure of the in-wheel motor 9 installed on the rear wheel 14 . The tire 140 of the rear wheel 14 is mounted on the rim 141 of the rear wheel, and the rim is connected to the hub 142 . Each hub motor 9 has a bearing 91, a motor winding 92, a permanent magnet 93 and a hall sensor 94 located in the hub, a brake drum 95 is provided at the opening of the hub, the hall sensor is located at the center of the hub, and the permanent magnet is located at the center of the hub. Between the sensor and the hub, the bearing is fixed at the opening of the hub, which is also in the inner space enclosed by the brake drum. The in-wheel motor 9 is equipped with a speed reducer with a fixed transmission ratio and a brake caliper 10 for realizing braking. The brake caliper 10 can be seen in FIG. 2 .

In this embodiment, the frame of the transporter is a bridge-type structure that bridges the front and rear wheels. As shown in FIG. 2 , the transporter is also provided with a leaf spring type dependent suspension frame 11 and a leaf spring fixing bracket 12 under the frame, and the leaf spring type dependent suspension frame is located on the frame and the axle 18 connecting the two rear wheels In between, the leaf spring fixing bracket surrounds the axle and is connected to the bottom of the frame, which is used to support the axle and the leaf spring type dependent suspension frame upwards. The leaf spring type dependent suspension frame and the leaf spring fixing bracket can dampen , the role of guidance.

The leaf spring type non-independent suspension frame is composed of multiple steel plates with unequal lengths and unequal curvatures. The effect of the force can be omitted, and the guide device and the shock absorber can be omitted, and the structure is simple. Wherein, the curvature of the steel plate stacked below is smaller than the curvature of the steel plate stacked above, and the length of the steel plate stacked below is smaller than the length of the steel plate stacked above.

As shown in Figure 2, each leaf spring type dependent suspension frame corresponds to two leaf spring fixing brackets, and the two leaf spring fixing brackets jointly clamp the leaf spring type dependent suspension frame, and the leaf spring type dependent suspension frame is Confined between the frame and the axle.

The electronic differential control system includes data acquisition sensors, a vehicle controller and two in-wheel motor drive controllers.

The data acquisition sensor includes a steering wheel angle position sensor, a rotational speed sensor, an acceleration signal sensor and a brake signal sensor, wherein the steering wheel angle position sensor is installed on the steering wheel rotation shaft, and is used to determine whether the steering wheel is rotated and detect the size of its rotation angle. In this embodiment, the steering wheel angle position sensor is a resistive sensor.

The acceleration signal sensor is installed on the accelerator pedal to detect the stroke of the accelerator pedal. The brake signal sensor is installed on the brake pedal to detect the stroke of the brake pedal. In this embodiment, both the acceleration signal sensor and the braking signal sensor are resistive sensors installed at the bottom of the corresponding pedal.

The rotational speed sensor is installed in the in-wheel motor inside the rear wheel to detect the rotational speed of the in-wheel motor. In this embodiment, as shown in FIG. 4 , the rotational speed sensor is a Hall sensor 94 disposed inside the in-wheel motor.

The vehicle controller is connected to the data acquisition sensor and the two in-wheel motor drive controllers, and is used to output the corresponding differential steering strategy to the in-wheel motor drive controller according to the real-time state parameters of the vehicle.

The real-time state parameters of the vehicle in this embodiment include in-wheel motor rotation speed, steering wheel angle, accelerator pedal stroke and brake pedal stroke collected by the data acquisition sensor, and vehicle speed calculated by the vehicle controller according to the in-wheel motor rotation speed.

The two in-wheel motor drive controllers are respectively connected to the corresponding in-wheel motors, and control the differential steering of the entire vehicle according to the differential steering strategy. The differential steering strategy of this embodiment is a table of relationships between vehicle speed, steering angle and wheel speeds inside and outside the curve, which is set according to the Ackerman-Jeantand turning model of the vehicle proposed by foreign scholar Ackerman.

When the transporter turns to drive and the steering wheel turns a certain angle in a certain direction, the steering wheel angle position sensor of the electronic differential control system judges the rotation of the steering wheel and detects the rotation angle, and the generated differential steering strategy is immediately executed by the in-wheel motor drive controller. . Therefore, the transport aircraft uses electronic differential control technology to replace the traditional mechanical differential to realize pure rolling of the inner and outer wheels at different rotational speeds when turning, which can make the transport aircraft steering control lighter and more flexible.

As shown in Figure 5, the vehicle controller has an AD conversion module, an IO signal module and a main controller. The AD conversion module is connected to the main controller, and sends the in-wheel motor speed and steering wheel angle in the real-time status parameters of the vehicle to the main controller. , accelerator pedal travel and brake pedal travel. The IO signal module is connected to the main controller, and sends the key start signal and gear selection signal input from the control panel of the transporter to the main controller.

The main controller is STM32 series chip. The main controller connects the two in-wheel motor drive controllers through the IO signal module, and sends the corresponding PWM output signal for controlling the speed of the in-wheel motor to the two in-wheel motor drive controllers. At the same time, the main controller is connected to the power supply through the IO signal module module, and send a start-up control signal to the power module.

The power module includes a 48V lead storage power supply, a DC/DC converter and a contactor. The lead storage power supply is connected to the DC/DC converter and is converted from the 48V power supply to the 5V power supply connected to the main controller through the DC/DC converter; the lead storage power supply The two in-wheel motor drive controllers are connected through a contactor, and power is supplied to the two in-wheel motor drive controllers when the contactor receives a start control signal.

The conveyor adopts the structure that the two in-wheel motor drive controllers receive signals from each module and independently control the acceleration and deceleration of the in-wheel motors on both sides. In addition, the in-wheel motor does not require a transmission system, so the transport aircraft has stronger air resistance and no emissions.

This embodiment also discloses a control method for the above-mentioned forest fruit tea garden conveyor, as shown in FIG. 6 , including the following steps:

S1. The vehicle controller of the electronic differential control system receives the key start signal and gear selection signal from the transporter console.

S2. The vehicle controller receives the wheel motor speed, steering wheel angle, accelerator pedal stroke and brake pedal stroke collected in real time by the data acquisition sensor, calculates the vehicle speed according to the wheel motor rotation speed, and then formulates two wheel hubs according to the real-time state parameter information of the vehicle. The differential steering strategy of the motor, and the differential steering strategy is transmitted to the in-wheel motor drive controller, as shown in Figure 7. The processing process is as follows:

S21. When the electronic differential control system is working normally, the IO signal module receives the key start signal and the gear selection signal and inputs them into the main controller, and the main controller begins to initialize: its internal ADC sampling function module, timer The module and the serial communication module are initialized, start the internal program, and the timer module distributes the clock; at the same time, the IO signal module sends a start-up control signal to the power module, so that the power module supplies power to the two wheel hub motor drive controllers;

S22. The AD conversion module receives the steering wheel angle collected by the steering wheel angle position sensor, the hub motor speed collected by the rotational speed sensor, the accelerator pedal stroke collected by the acceleration signal sensor, and the brake pedal stroke collected by the brake signal sensor, and converts these The analog signal is converted into a digital signal and input to the main controller;

S23. After receiving the speed signal of the hub motor, the stroke of the accelerator pedal and the stroke of the brake pedal, the main controller calculates the current vehicle speed and the actual speed required by the hub motors of the left and right rear wheels, and outputs the PWM duty cycle to the hub motor drive controller To control the current speed of the hub motor, and then control the speed of the transport locomotive;

In this process, after starting the ADC program to collect the information of each sensor, it stops the timing operation of the timer module, and then enters the interrupt program to analyze the information of each sensor:

If the sensor information indicates that the transporter does not perform steering behavior, that is, "No" in the timing interruption, the steps after the timing interruption will not be executed, and the AD conversion of each sensor information will continue;

If the sensor information indicates that the transporter wants to turn, that is, "Yes" in the timing interruption, the steering procedure after the timing interruption is executed. Since the transporter in this embodiment is driven independently by dual-wheel motors, the traditional mechanical differential of the rear axle of the vehicle is removed. Assembly, in order to maintain the stability of the vehicle cornering, the two in-wheel motors must have active differential drive capability. Therefore, after receiving the steering wheel angle signal, the main controller performs active differential calculation according to the steering wheel angle signal, that is, according to the differential speed. The steering strategy algorithm calculates the different speeds of the two rear wheels, and sends PWM output signals with different duty ratios to the two in-wheel motor drive controllers through the IO signal module.

As mentioned above, the main loop process of the main controller is a key part of the entire program, and it can perform infinite loops during program execution to analyze the state of the conveyor in real time.

S3. The two in-wheel motor drive controllers control the in-wheel motor of the in-wheel motor power system according to the differential steering strategy: the current speed of the rear-wheel in-wheel motor located on the outside of the curve remains unchanged, and the rear-wheel in-wheel motor located on the inner side of the curve according to the actual needs. The speed difference reduces the speed, so as to control the differential steering of the whole vehicle, and improve the stability of the vehicle when the vehicle is cornering.

The above-mentioned embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above-mentioned embodiments, and any other changes, modifications, substitutions, combinations, The simplification should be equivalent replacement manners, which are all included in the protection scope of the present invention.

Claims (10)

1. The utility model provides a forest and fruit tea garden cargo airplane based on in-wheel motor drive which characterized in that includes: the parking device comprises a frame, a vehicle body arranged on the frame, a control console, a limit parking system with an accelerator pedal and a brake pedal, a steering system with a steering wheel, a hub motor power system and an electronic differential control system, wherein,

the hub motor power system comprises a power module, two permanent magnet brushless torque hub motors, two agricultural mountain land type front wheels respectively positioned on the left side and the right side of the frame and two agricultural mountain land type rear wheels positioned behind the front wheels, the power module is connected with the two hub motors, and the two hub motors are respectively integrated into the hubs of the corresponding rear wheels and used as driving devices of the transporter;

the electronic differential control system comprises a data acquisition sensor, a vehicle control unit and two hub motor drive controllers, wherein the vehicle control unit is connected with the data acquisition sensor and the hub motor drive controllers and is used for outputting corresponding differential steering strategies to the hub motor drive controllers according to real-time state parameters of a vehicle; the finished automobile real-time state parameters comprise the rotating speed of the hub motor, the steering wheel rotating angle, the travel of an accelerator pedal and the travel of a brake pedal which are acquired by a data acquisition sensor, and the automobile speed calculated by the finished automobile controller according to the rotating speed of the hub motor;

the two hub motor driving controllers are respectively connected with the corresponding hub motors and control the differential steering running of the whole vehicle according to a differential steering strategy.

2. The forest and fruit tea garden conveyor based on in-wheel motor drive of claim 1, wherein the data acquisition sensor comprises a steering wheel angle position sensor, a rotating speed sensor, an acceleration signal sensor and a brake signal sensor, wherein,

the steering wheel corner position sensor is arranged on a steering wheel rotating shaft and used for judging whether the steering wheel rotates or not and detecting the size of a corner of the steering wheel; the rotating speed sensor is arranged in the hub motor in the rear wheel and used for detecting the rotating speed of the hub motor; the acceleration signal sensor is arranged on an accelerator pedal and used for detecting the stroke of the accelerator pedal; the brake signal sensor is mounted on the brake pedal and used for detecting the stroke of the brake pedal.

3. The forest and fruit tea garden conveyor based on the driving of the hub motor according to claim 1, wherein the frame of the conveyor is of an bridge type structure bridged on front and rear wheels;

the transporter is also provided with a leaf spring type dependent suspension bracket and a leaf spring type dependent suspension bracket under the frame, the leaf spring type dependent suspension bracket is positioned between the frame and an axle connected with two rear wheels, and the leaf spring type dependent suspension bracket wraps the axle and is connected to the bottom of the frame and is used for upwards supporting the axle and the leaf spring type dependent suspension bracket; the hub motor is fixed on the axle through a fixing bolt.

4. The in-wheel motor driven forest and fruit tea garden conveyor based on claim 3, wherein the leaf spring type non-independent suspension bracket is formed by overlapping a plurality of steel plates with unequal lengths and curvatures, two ends of the overlapped steel plates are naturally bent upwards and arranged longitudinally, the curvature of the steel plate overlapped at the lower part is smaller than that of the steel plate overlapped at the upper part, and the length of the steel plate overlapped at the lower part is smaller than that of the steel plate overlapped at the upper part.

5. The in-wheel motor driven forest and fruit tea garden conveyor based on claim 3, characterized in that each leaf spring type dependent suspension bracket corresponds to two leaf spring fixing brackets, and the two leaf spring fixing brackets clamp the leaf spring type dependent suspension bracket together, so that the leaf spring type dependent suspension bracket is limited between the frame and the axle.

6. The forest and fruit tea garden conveyor based on the driving of the hub motor as claimed in claim 1, wherein the hub motor is a low-speed outer rotor motor, and a speed reducer with a fixed transmission ratio and a brake caliper for realizing braking are arranged on the hub motor;

the rotating speed sensor is a Hall sensor arranged in the hub motor; the steering wheel corner position sensor, the acceleration signal sensor and the brake signal sensor are all resistance sensors.

7. The forest and fruit tea garden conveyor based on the driving of the hub motor according to claim 1, wherein the vehicle control unit is provided with an AD conversion module, an IO signal module and a main controller, the AD conversion module is connected with the main controller and sends the rotating speed of the hub motor, the steering wheel rotating angle, the travel of an accelerator pedal and the travel of a brake pedal in the real-time state parameter information of the vehicle to the main controller;

the IO signal module is connected with the main controller and sends a key starting signal and a gear selection signal which are input by the control panel of the transport vehicle to the main controller;

the main controller is connected with the two hub motor driving controllers through the IO signal module and sends corresponding PWM output signals for controlling the rotating speed of the hub motors to the two hub motor driving controllers; the main controller is connected with the power supply module through the IO signal module and sends a starting control signal to the power supply module.

8. The in-wheel motor driven forest and fruit tea garden conveyor is characterized in that the power supply module comprises a lead storage power supply, a DC/DC converter and a contactor, wherein the lead storage power supply is connected with the DC/DC converter and is converted into a 5V power supply connected with the main controller through the DC/DC converter; the lead power storage source is connected with the two hub motor driving controllers through the contactor, and supplies power to the two hub motor driving controllers under the condition that the contactor receives the starting control signal.

9. A control method of a forest and fruit tea garden conveyor based on hub motor drive is characterized in that the forest and fruit tea garden conveyor based on hub motor drive as claimed in any one of claims 1-8, and the control method comprises the following steps:

s1, the vehicle controller of the electronic differential control system receives a key starting signal and a gear selection signal from a transport vehicle console;

s2, the vehicle control unit receives the rotating speed of the hub motors, the steering wheel rotating angle, the travel of the accelerator pedal and the travel of the brake pedal which are acquired by the data acquisition sensor in real time, calculates the vehicle speed according to the rotating speed of the hub motors, then formulates differential steering strategies of the two hub motors according to the real-time state parameter information of the whole vehicle, and transmits the differential steering strategies to the drive controller of the hub motors;

and S3, controlling the hub motors of the hub motor power system by the two hub motor driving controllers according to a differential steering strategy so as to control the whole vehicle to run in a differential steering mode.

10. The control method of the forest and fruit tea garden conveyor based on the driving of the hub motor according to claim 9, wherein the whole vehicle controller is processed as follows:

s21, under the condition that the electronic differential control system works normally, the IO signal module receives a key starting signal and a gear selection signal and inputs the signals into the main controller, and the main controller starts initialization: an ADC sampling function module, a timer module and a serial port communication module in the device are initialized, an internal program is started, and the timer module distributes a clock;

meanwhile, a starting control signal is sent to the power supply module through the IO signal module, so that the power supply module supplies power to the two hub motor driving controllers;

s22, an AD conversion module receives a steering wheel angle acquired by a steering wheel angle position sensor, the rotating speed of a hub motor acquired by a rotating speed sensor, the travel of an accelerator pedal acquired by an acceleration signal sensor and the travel of a brake pedal acquired by a brake signal sensor, converts the analog signals into digital signals and inputs the digital signals into a main controller;

s23, after receiving the rotation speed signal of the hub motor, the travel of an accelerator pedal and the travel of a brake pedal, the main controller calculates the current speed and the actually required rotation speed of the hub motors of the left and right rear wheels, and outputs PWM duty ratio to the hub motor driving controller to control the current rotation speed of the hub motor, so as to control the speed of the transporter;

in the process, after the ADC program in the ADC sampling function module is started to collect the information of each sensor, the timing operation of the timer module is stopped, and then an interrupt program is started to analyze the information of each sensor:

if the sensor information indicates that the conveyor does not perform steering action, the following steps are not executed, and AD conversion is continuously performed on the sensor information;

if the sensor information indicates that the conveyor is to turn, executing a turning program after timed interruption, specifically: after receiving the steering wheel angle signal, the main controller performs active differential operation according to the steering wheel angle signal, and sends PWM output signals with different duty ratios to the two hub motor drive controllers through the IO signal module;

according to the differential steering strategy, the hub motor is controlled, and the method specifically comprises the following steps: the current rotating speed of the rear wheel hub motor positioned on the outer side of the curve is unchanged, and the rotating speed of the rear wheel hub motor positioned on the inner side of the curve is reduced according to the actually required rotating speed difference.

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