CN112471111A

CN112471111A - Height and wheel track adjustable intelligent driving electric plant protection operation vehicle

Info

Publication number: CN112471111A
Application number: CN202011362596.1A
Authority: CN
Inventors: 李�赫; 张开飞; 程上上; 赵弋秋; 郭长乐; 牛潇潇; 张亚辉; 秦超斌; 丁力
Original assignee: Henan Agricultural University
Current assignee: Henan Agricultural University
Priority date: 2020-11-27
Filing date: 2020-11-27
Publication date: 2021-03-12

Abstract

The invention belongs to the technical field of agricultural machinery, and particularly relates to an intelligent driving electric plant protection working vehicle with adjustable height and wheel track, which comprises a front vehicle frame, a rear vehicle frame, a bowing steering mechanism, a wheel track adjusting mechanism, a height adjusting mechanism and a spray rod mechanism; the rear frame is provided with a medicine box, a diaphragm pump and a portal frame, and the wheel track adjusting mechanism is arranged between the moving wheel and the frame; the height adjusting mechanism comprises a connecting seat, a U-shaped bolt and a wheel carrier, and the spray rod mechanism comprises a lifting frame, a side wheel, an electric push rod, a main spray rod and a side spray rod; the two sides of the lifting frame are provided with side wheels which are nested on the tracks on the two sides of the portal frame; the main spray rod is fixed on the lifting frame, and the side spray rods are arranged on the main spray rod in a folding mode, so that the adaptability of the plant protection spraying machine can be adjusted according to the line spacing and the plant height of operation, the plant protection spraying machine can be suitable for full-period spraying of plant protection, the universality is high, the control mode adopts remote control, and the intelligent degree of plant protection operation is improved.

Description

Height and wheel track adjustable intelligent driving electric plant protection operation vehicle

Technical Field

The invention belongs to the technical field of agricultural machinery, and particularly relates to an intelligent driving electric plant protection working vehicle with adjustable height and wheel track.

Background

The agricultural machinery is wide in land, rich in agricultural environment, various in crop types, obvious in difference of agricultural requirements of crops such as wheat and soybean, obvious in row spacing, incapable of realizing generalization of agricultural machinery due to fixed wheel track, large in plant height change along with growth of crops, unadjustable in height of a traditional plant protection vehicle, only capable of walking between rows and incapable of crossing over the crops.

The driving power of the existing agricultural machinery is generally driven by an engine, and along with the increasing capacity of a battery, the battery can be used as power for the agricultural machinery, and compared with a transmission driving mode, the agricultural machinery has the advantages of light weight, energy conservation, environmental protection and the like; meanwhile, the wheel track and the height of the traditional agricultural machine cannot be adjusted according to the growth of crops, and the universality is poor.

The operation mode of current agricultural machinery generally turns to and walks for manual operation steering wheel, this kind of structure relies on the manpower to realize mostly, the manpower has been wasted, especially severe to operational environment, if it is hot weather etc., it carries out the operation to need people to endure high temperature environment, it is intelligent low, give people and brought the trouble, the height and the wheel base of current agricultural machinery can't carry out the regulation of adaptability according to the height and the line interval of crop simultaneously, troublesome poeration, therefore, it is necessary to study a height, wheel base adjustable intelligence drive electronic plant protection operation car.

Disclosure of Invention

Aiming at the defects and problems of the existing equipment, the invention provides the intelligent driving electric plant protection operating vehicle with adjustable height and wheel track, and effectively solves the problems of unadjustable wheel track and height and low intellectualization of an agricultural machine driving mode in the existing equipment.

The technical scheme adopted by the invention for solving the technical problems is as follows: an intelligent driving electric plant protection operation vehicle with adjustable height and wheel track comprises a front vehicle frame, a rear vehicle frame, a bowing steering mechanism, a wheel track adjusting mechanism, a height adjusting mechanism and a spray rod mechanism; the front frame and the rear frame are connected through a articulated steering mechanism to form a frame main body, a power supply and a remote control receiver are installed on the front frame, a medicine box, a diaphragm pump and a portal frame are installed on the rear frame, and the wheel track adjusting mechanism is arranged between the movable wheels and the frame; the height adjusting mechanism comprises a connecting seat, a U-shaped bolt and a wheel frame, the connecting seat is fixed on the frame, the U-shaped bolt penetrates through the connecting seat and fixes the wheel frame on the connecting seat, moving wheels are installed at the bottom of the wheel frame, and each moving wheel is provided with a driving motor; the articulated steering mechanism comprises a steering motor, a front steering frame, a rear steering frame, a gear set and a driving shaft, wherein a front steering frame and a rear steering frame are respectively fixed at the joint of the front frame and the rear frame; the steering motor is arranged on a rear steering frame through a bracket, the front steering frame is fixed on a driving shaft, and the rear steering frame is rotatably arranged at two ends of the driving shaft; the steering motor is in transmission connection with the driving shaft through a gear set, so that the front bogie can rotate relative to the rear bogie under the driving of the steering motor; the spray rod mechanism comprises a lifting frame, side wheels, an electric push rod, a main spray rod and side spray rods; the electric push rod is arranged between the lifting frame and the portal frame and used for driving the lifting frame to lift along the portal frame; the main spray rod is fixed on the lifting frame, and the side spray rod is arranged on the main spray rod in a folding mode.

Further, the gear set comprises a driving gear, a driven gear, a sleeving gear and a driving gear; a rotating shaft of the steering motor is sleeved with a driving gear, the driving gear is meshed with a driven gear, a sleeving gear is coaxially sleeved at the lower part of the driven gear, and the driving gear is meshed with the sleeving gear; the lower part of the driving gear is fixedly sleeved on the upper part of the driving shaft.

Furthermore, folding pieces are arranged between two sides of the main spray rod and the side spray rods, and each folding piece comprises an upper transverse plate, a lower transverse rod, a middle shaft, a clamping seat and a blocking piece; the upper transverse plate and the lower cross rod are respectively arranged at the upper end and the lower end of the main spray rod along the horizontal direction, and the middle shaft vertically penetrates through the upper transverse plate and the lower cross rod and can rotate; the clamping seat is in a trapezoidal structure, the clamping seat is fixed on the middle shaft, the bottom of the clamping seat is clamped on the circular tubular lower cross rod, the blocking piece is positioned on the upper portion of the middle shaft, and the spring is sleeved on the middle shaft and positioned between the blocking piece and the clamping seat.

Furthermore, the wheel track adjusting mechanism comprises an adjusting sleeve, an adjusting rod and a limiting bolt; the adjusting sleeve is fixed on the front frame, the adjusting rod is sleeved in the adjusting sleeve, and the adjusting sleeve and the adjusting rod are respectively provided with a fixing hole and a plurality of positioning holes; the limiting bolt is adjusted in the fixing hole and the positioning hole to keep the positions of the adjusting rod and the adjusting sleeve.

Furthermore, a clamping groove is formed in the wheel carrier, scales are correspondingly marked on the clamping groove, and the U-shaped bolt is matched with the clamping groove in a clamping mode.

The device further comprises a control system, wherein the control system comprises a sensor, an upper computer, a controller, a diaphragm pump, a driving motor and a steering motor; the sensor is used for receiving vehicle condition information of the plant protection vehicle and uploading the vehicle condition information to the controller, the upper computer sends an instruction to the controller through the wireless module, the controller analyzes the vehicle condition information and the instruction after receiving the vehicle condition information and the instruction, and the spray power, the vehicle speed and the steering of the plant protection vehicle are adjusted by controlling the work of the diaphragm pump, the driving motor and the steering motor.

The invention has the beneficial effects that: the invention adopts a lightweight structural design, improves the driving mode and lightens the land compaction; the design of the vehicle body has adjustability so as to adapt to different crops such as wheat, corn, soybean and the like; a motor is selected as power, and a storage battery is used as a power source, so that the intelligent control level of machinery is improved; the operation vehicle can be remotely controlled by a remote controller, and after the automatic mode is switched, path tracking can be carried out according to a preset route, so that the operation vehicle can automatically walk. The development of the autonomous walking plant protection operation vehicle can reduce the pesticide consumption and the production cost, reduce the operation harm and improve the operation efficiency.

The operating vehicle adopts the scheme that the wheel track and the ground clearance of the chassis are adjustable structurally and four-wheel drive is matched dynamically, wherein the wheel track adjusting structure is adjustable within the range of 1-1.3 m, and the ground clearance of the chassis is designed to be adjustable within the range of 0.5-1.3 m. Determining a path tracking strategy, and analyzing the stability of steering control through a Lyapunov function; in order to improve the control precision of the plant protection operating vehicle, an extended Kalman filtering algorithm of a sensor and a PID control mode of a driving motor are provided; the vehicle with the articulated steering coordinated steering is more mobile and better than the sliding steering, so that the maximum thrust provided by the driving element can be kept during the turning of the plant protection vehicle;

the spray lance is designed to be 6m in width, the most reasonable size after the spray lance is folded is not greatly different from the wheel track, and the transition operation can be better carried out. The multi-section folding method is adopted, a structure capable of pressing and rotating is designed at the joint of the main spray rod and the side spray rod, the clamping seat is fixed on the middle shaft and clamped on the lower cross rod, the blocking piece is positioned on the upper portion of the middle shaft, the spring is sleeved on the middle shaft and positioned between the blocking piece and the clamping seat, the trapezoidal groove is used for fixing, the structure can be conveniently folded or unfolded, and meanwhile, the balance and the stability during operation are guaranteed.

Therefore, the plant protection operation vehicle with the adjustable wheel track and height provided by the invention can be used for adjusting the adaptability according to the line spacing and the plant height of operation, is suitable for spraying in the whole plant protection period, and has strong universality.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a front view of fig. 1.

Fig. 3 is a front view of fig. 1.

Fig. 4 is a rear view of fig. 1.

Fig. 5 is a schematic structural view of the vehicle frame.

Fig. 6 is a top view of fig. 5.

Fig. 7 is a front view of fig. 5.

Fig. 8 is a schematic view of the structure of the folding member.

Fig. 9 is a schematic view of a bow turn structure.

Fig. 10 is another view of fig. 9.

Fig. 11 is another structural schematic diagram of the track width adjusting mechanism.

Fig. 12 is a block configuration diagram of the control system.

Fig. 13 is a block diagram of the attitude acquisition.

Fig. 14 is a block diagram of path tracking.

FIG. 15 is a graph of the kinematic coordinates of the walking system.

Fig. 16 shows the error between the work vehicle and the target point in polar coordinates.

FIG. 17 is a schematic view of strapdown inertial navigation.

FIG. 18 is a block diagram of a PID controller.

Fig. 19 is an equivalent circuit of a motor armature.

Fig. 20 is a schematic diagram of a dynamic structure of the dc motor.

The reference numbers in the figures are: 1 is a front frame, 2 is a rear frame, 3 is a bowing steering mechanism, 31 is a steering motor, 32 is a driving gear, 33 is a driven gear, 34 is a sleeving gear, 35 is a driving gear, 36 is a driving shaft, 37 is a front steering frame, and 38 is a rear steering frame; 4 is a power supply, 5 is a remote control receiver, 6 is a medicine box, 7 is a portal frame, 8 is a lifting frame, 9 is a side wheel, 10 is a main spray rod, 11 is a side spray rod, 12 is an adjusting sleeve, 13 is an adjusting rod, 14 is a connecting seat, 15 is a U-shaped bolt, 16 is a wheel carrier, 17 is a moving wheel, 18 is an upper transverse plate, 19 is a lower transverse rod, 20 is a middle shaft, 21 is a clamping seat, 22 is a spring and 23 is a blocking piece; 24 is a rack and 25 is a gear.

Detailed Description

The invention is further illustrated with reference to the following figures and examples.

Example 1: this embodiment aims at providing a height, electronic plant protection operation car of intelligent drive of wheel track adjustable, the mainly used plant protection field, along with the growth of crop, its plant height changes, and there is the difference in the row spacing of different crops, traditional plant protection car can't be adjusted according to these changes, cause its commonality poor, and the operation mode is mostly manual operation, operating personnel exposes in abominable environment, give people and brought the trouble, for this reason, this embodiment provides a frame height, the electronic plant protection car of remote control of wheel track adjustable.

As shown in fig. 1, an intelligent driving electric plant protection working vehicle with adjustable height and wheel track comprises a front frame 1, a rear frame 2, a bowing steering mechanism 3, a wheel track adjusting mechanism, a height adjusting mechanism and a spray rod mechanism; preceding frame 1 and back frame 2 connect through bowing steering mechanism 3 and form the frame main part, install power 4 and remote control receiver 5 on the preceding frame 1, install medical kit 6, diaphragm pump and portal frame 7 on the back frame 2, owing to adopt remote control in this embodiment, the frame need not bear engine, people's gravity, and the frame adopts light material, only need bear the gravity of power and medical kit can, alleviate the whole dead weight of soil compaction and plant protection car, it is lighter, be convenient for transport, accomodate and put in.

The wheel track adjusting mechanism is arranged between the movable wheel 17 and the frame; the wheel track adjusting mechanism comprises an adjusting sleeve 12, an adjusting rod 13 and a limiting bolt; the adjusting sleeve 12 is fixed on the front frame 1, the adjusting rod 13 is sleeved in the adjusting sleeve 12, and the adjusting sleeve 13 and the adjusting rod 12 are respectively provided with a fixing hole and a plurality of positioning holes; the adjusting device comprises a frame, a regulating sleeve, a fixing hole, a limiting bolt, a positioning rod, a limiting bolt, a positioning rod, a positioning hole and a limiting bolt.

The height adjusting mechanism comprises a connecting seat 14, a U-shaped bolt 15 and a wheel frame 16, wherein the connecting seat 14 is fixed at the tail end of the adjusting rod 13, as shown in fig. 1-4, the connecting seat 14 is vertically fixed at the outer side end of the adjusting rod, the U-shaped bolt 15 penetrates through the connecting seat 14 and hoops the wheel frame 16 on the connecting seat 14, the bottom of the wheel frame 16 is provided with a moving wheel 17, and each moving wheel is provided with a driving motor; the wheel frame can slide up and down relative to the connecting seat by loosening the U-shaped bolt, the height of the frame relative to the wheel frame is adjusted, and after the height of the frame is adjusted in place, the U-shaped bolt is screwed down, so that the height of the frame relative to a plant at the bottom of the frame can be adjusted.

The articulated steering mechanism 3 comprises a steering motor 31, a front steering frame 37, a rear steering frame 38, a gear set and a driving shaft 36, wherein the front steering frame 37 and the rear steering frame 38 are respectively fixed at the butt joint of the front frame 1 and the rear frame 2; the steering motor 31 is mounted on a rear bogie 38 through a bracket, the front bogie 37 is fixed on a driving shaft 36, and the rear bogie 38 is rotatably arranged at two ends of the driving shaft 36; the steering motor 31 is in transmission connection with the driving shaft 36 through a gear set, so that the front bogie can rotate relative to the rear bogie under the driving of the steering motor; the gear set comprises a driving gear 32, a driven gear 33, a sleeving gear 34 and a driving gear 35; a rotating shaft of the steering motor is sleeved with a driving gear, the driving gear is meshed with a driven gear, a sleeving gear is coaxially sleeved at the lower part of the driven gear, and the driving gear is meshed with the sleeving gear; the lower part of the driving gear is fixedly sleeved on the upper part of the driving shaft.

In the embodiment, the steering motor 31 is in transmission connection with the gear set, then power is transmitted to the driving shaft 36, the driving shaft rotates to enable the front bogie to rotate relative to the rear bogie, so that the directional steering of the frame can be realized through the rotating speed and the steering of the steering motor 31, and equipment support is provided for remote control steering.

The spray rod mechanism comprises a lifting frame 8, a side wheel 9, an electric push rod, a main spray rod 10 and a side spray rod 11; the two sides of the lifting frame 8 are provided with side wheels 9, the side wheels 9 are nested on the tracks on the two sides of the portal frame 7, and the electric push rod is arranged between the lifting frame and the portal frame and used for driving the lifting frame to lift along the portal frame; the main spray rod 10 is fixed on the lifting frame 8, and the side spray rod 11 is arranged on the main spray rod 10 in a folding mode.

The control system comprises an attitude sensor, an upper computer, a controller, a diaphragm pump, a driving motor and a steering motor; the plant protection vehicle comprises a plant protection vehicle body, an attitude sensor, an upper computer, a diaphragm pump, a driving motor, a steering motor, a controller and a host computer, wherein the attitude sensor is used for receiving vehicle condition information of the plant protection vehicle and uploading the vehicle condition information to the controller, the host computer sends an instruction to the controller through the wireless module, and the signal output end of the controller respectively controls the diaphragm pump, the driving motor and the steering motor to work so as to adjust the spraying power, the vehicle speed and the steering of the.

Specifically, in this embodiment, as shown in fig. 12, the attitude sensor includes a magnetometer, a gyroscope, and a GPS positioning module, the magnetometer, the gyroscope, and the GPS positioning module perform kalman filtering on the data, and according to matrix data of attitude data conversion (coordinate transformation), yaw correction is performed, and a yaw accumulated value is calculated to obtain target accelerator speed and target steering speed data:

1. matrix of vehicle motion models

In FIG. 15, O is a hinge point with motor assisted steering; o is₁、O₂Respectively as the front and rear axle centers; phi is a steering angle; theta₁、θ₂The azimuth angles of the front and rear frames; l₁The length between the front frame hinge joint and the front axle center, l₂The length between the rear frame articulation joint and the rear axle center, l₁＝l₂(ii) a W is the wheel tread of the frame; c is the center of the radius of rotation of the platform

To derive the kinematic equations of the walking platform, several cases need to be assumed: the platform steering angle phi is kept constant under the condition of small displacement; neglecting dynamic effects caused by low speed; the walking platform has no sliding effect when moving on a plane.

The non-integrity integral constraints of the front and rear frames can be represented by the following equation:

the kinematic relationship between the steering angle phi and the azimuth angles of the front and rear frames can be expressed as

The translational motion equation of the front frame can be expressed as:

velocity v₁And v₂The velocity of the rigid free joint relative to the vehicle is considered to have the same variation, so the relative velocity vector equation can be defined as:

is obtained by combining (3), (6) and (7)

Angle of rotation

And theta₁It can be measured very accurately, because of the hinged installation of the auxiliary steering motor, there is a steering restriction in the rear part of the drive, and the relationship between the front frame and the rear frame can be expressed as:

x₂＝x₁-l₁ cosθ₁-l₂ cosθ₂ (10)

y₂＝y₁-l₁ sinθ₁-l₂ sinθ₂ (11)

in the proposed method, the variable is the rate of change of the bow angle

While the speed of the vehicle is considered constant, with initial parameters

The real dynamic motion behavior of the walking platform is shown in fig. 1. Because, set l₁＝l₂The matrix of the vehicle motion model is:

2. yaw correction

For the two-dimensional coordinate points of the preset path, the working vehicle needs to adjust the steering and update the path points according to the self information and the target information, so that the movement process of the working vehicle in the geodetic coordinate system is established as shown in FIG. 16

x＝-ecosθ_r (14)

y＝-esinθ_r (15)

In the formula: e-error distance;

θ_r-error vector direction relative to the target;

θ_tthe angle between the distance vector e and the linear velocity vector.

(13) Can be written as

Combine (14), (15) and (16) to obtain

Substituting (4) and (5) into (17) to obtain

Substituting the time inverses of (14) and (15) into (4) and (5) to obtain

From the analysis of FIG. 2, θ can be found_t＝θ_r-ψ，

Combined with kinematic analysis to obtain

In combination with the kinematic model matrix (12), the equation of motion of the work vehicle in polar coordinates can be generalized as

In the field of automatic control, Lyapunov stability (Lyapunov stability) may be used to describe the stability of a powertrain system. The Lyapunov stability theory is a common tool for designing control systems. Here we consider a simple quadratic equation as the candidate Lyapunov function.

The purpose of the steering control system is to control the vehicle to align it precisely with the target. It is the practice to find a stable control law

Capable of driving the working vehicle from any initial position (e (0), theta)_r(0),θ_t(0) A small neighborhood (0,0,0) to the target.

Considering positive definite form

The time derivative of V is

Substituting (22) into (24) to obtain

Is unfolded to obtain

Through stability theoretical analysis, can obtain

In combination with equation (20), one can obtain

When lambda is₂Is greater than 0 and

to be positive, find theta from (4-51)_rIs stable and eventually approaches zero, it can proceed slowly.

Therefore, the temperature of the molten metal is controlled,

result in (e, theta)_r，θ_t) → (0,0, 0). Since the system has no drift. In practice, a trade-off is required in selecting the parameters, setting λ₄Stable (e, theta) 0_r，θ_t) While making phi uncontrollable. In this case, φ may take a physically unachievable value, for example, to fold the bow-steer chassis over itself. In contrast, λ₄Choosing too large results in a very slow origin. It should also be mentioned that the proposed center articulated work vehicle model has a singularity when e is 0, since according to equations (4-22) no singularities are defined at that time

And

the condition e-0 cannot occur within a limited time.

Finally, we have noticed that there is a special case where the controller is not able to stabilize the configuration of the robot. When phi and theta_tThis special case occurs when all are initially zero. As can be observed from equations (26) and (27), in this case, ω ═ 0 and v ═ λ₁，θ_rIt will not be controllable. The control system identifies the special condition and takes proper measures, the initial angle can be set to be nonzero, the output target attitude value is set for the driving motor and the steering motor, and PWM output of each motor is calculated; calling communication subprogram, communicating with upper computer, and real-time checking working parameters (working vehicle speed, environment information and path)Information) to display and adjust.

The variable being the rate of change of the waist angle

While the speed of the vehicle is considered constant, with initial parameters

The matrix of the vehicle motion model is:

3. strapdown inertial navigation

The inertial navigation system is divided into platform type inertial navigation and strapdown inertial navigation, the early inertial navigation systems are all platform type inertial navigation systems, the platform type inertial navigation system is provided with a physical platform, a gyroscope and an accelerometer are arranged on the platform stabilized by the gyroscope, the platform tracks a navigation coordinate system to realize speed and position resolving, and attitude data is directly obtained from a ring frame of the platform.

The advantages are that: a navigation coordinate system is directly simulated, and the calculation is simpler; the angular motion of carrier can be kept apart, and system's precision is high, the shortcoming: the structure is complicated, the volume is large, and the manufacturing cost is high.

There is another strapdown inertial navigation, and the English original meaning of strapdown is the meaning of 'binding'. Therefore, the strapdown inertial navigation is to directly mount inertial measurement elements including a gyroscope and an accelerometer on a main body requiring navigation information such as attitude, speed, course and the like, and convert measurement signals of a computer into navigation parameters.

The advantage does not have the platform, and the framework is simple, and is small, and it is convenient to maintain, shortcoming: the inertia element is directly arranged on the carrier, the environment is severe, and the requirement on the element is high; the calculation amount in the coordinate transformation is large, and the strapdown inertial navigation has obvious advantages compared with the platform inertial navigation in the whole view.

4. Motor control

4.1 PID control

The source of PID (proportional-integral-derivative) controllers was the governor design in the 90 s of the 19 th century. PID controllers were developed in the automatic operating systems of ships, the controller developed by Elmer Sperry in 1911 being one of the earliest PID controllers, and the first engineer who published the theoretical analysis theory of PID controllers was the russian american engineer nigulas minorski (Nicolas Minorsky, 1922). Minorski derives a mathematical formula on the basis of the controller, with the aim of stability, rather than general control, which greatly simplifies the problem. Proportional control can remain stable under small disturbances, but does not eliminate steady-state errors, thus adding an integral term followed by a differential term.

The control loop consists of three parts: the controller makes decisions based on measurements taken by the system sensors and then reacts by executing hardware. The controller takes a measurement from the sensor and then subtracts the measurement from the demand result to obtain a difference. This value is used to calculate a correction value for the system as an input so that the system can eliminate errors in its output. The correction has three algorithms to eliminate the current error value, average the past error value, and predict the future error value by the difference change.

The PID controller can be used to control any variable that can be measured and controlled. For example, it may be used to control temperature, pressure, flow, chemical composition, velocity, and the like. The cruise function on a car is an example. In industrial control applications, a PID controller is a common feedback loop component. The controller compares the collected data with a reference value and then calculates a new input value using the difference value. The purpose of the calculation is to allow the system data to reach or be maintained at the reference value. The PID controller can adjust the input values based on historical data and the incidence of differences to improve the accuracy and stability of the system, and can be considered as a filter for a frequency domain system as shown at 16. This property is important in calculating whether the controller will eventually reach a stable result. If the values are not properly selected, the input values to the control system will oscillate repeatedly, resulting in the system never reaching the preset values. If the control output is defined as u (t), the PID time domain expression is as follows

In the formula: k_p-proportional gain, debugging parameters;

K_i-integral gain, tuning parameters;

K_d-differential gain, tuning parameters;

e-error, difference between set value and measured value;

t is the current time;

τ -integral variable, value 0 to current time;

T_i-integrating the time constant;

T_d-a differential time constant.

The PID controller obtains a control signal u (t) by weighting the error signal e (t), drives the controlled object, and changes the error e (t) along the reducing direction, thereby realizing the control requirement. If T_i→∞，T_d0, a ratio (P) controller; if T_d0, Proportional Integral (PI) controller; when T is_iProportional Derivative (PD) controller → ∞ time; if T_i≠∞，T_dNot equal to 0, is a Proportional Integral Derivative (PID) controller. Determination of K_p，T_i，T_dAfter the three parameter values, the performance of the PID controller is determined.

Analyzing FIG. 4-5, Laplace transform is performed on (4-1) to obtain the transfer function of PID controller

4.2 drive Motor control

1) Mathematical model of driving motor

The driving motor of the working vehicle is a separately excited motor^[76]Deducing the induced electromotive force and electromagnetic torque of the driving motor according to the structure and the law of electromagnetic induction, and establishing the voltage balance mode of the motor by the kirchhoff second law (KVL)

E＝K_eΦn_m＝C_en_m (4-3)

In the formula: e-driving motor induced electromotive force, V;

K_e-an electromotive force constant;

Φ — flux per pole of the machine, Wb;

n_m-motor speed, r/min;

C_e-potential to rotational speed ratio at rated flux (V.min/r), and C_e＝K_eΦ。

T_e＝K_TΦI_m＝C_mI_m (4-4)

In the formula: t is_e-driving motor electromagnetic torque, N · m;

K_T-a torque constant determined by the motor construction;

I_m-the armature current, a;

C_m-torque current ratio N m/A, C under rated flux_m＝30π^-1C_e。

The equivalent circuit of the armature when the driving motor operates is shown in FIG. 19, and the differential equations can be listed as follows

In the formula: t is_m-motor output torque, N · m;

T_L-load torque, N · m;

j-moment of inertia, N.m²。

According to the theoretical analysis of the DC motor drive system,

is the time constant of the armature return cell,

is the electromechanical time constant of the electric traction system. Under the zero initial condition, the time constant is substituted into (4-5) and (4-6), and the two sides of the equation are transformed by the Laplace equation to obtain the transfer function of the voltage-current linear response system

Current and electromotive force transfer function of

In the formula: i is_dL-a load current.

The dynamic structure of the dc motor is obtained through formulas (4-6), (4-7), and (4-8), as shown in the schematic diagram of the dynamic structure of the dc motor in fig. 20.

The acquisition of the plant protection operation attitude is very important for automatic walking, and the accuracy and reliability of data are ensured by the cooperation of a strapdown inertial navigation system and a satellite navigation positioning system. Filtering data output by the gyroscope and the accelerometer by adopting an extended Kalman filtering algorithm, and if the interference value is too large, adding coordinate information of a GPS (global positioning system) to settle attitude information of the operation vehicle; the specific flow of gesture acquisition is shown in fig. 13.

The control mode of the autonomous plant protection operation vehicle adopts a manual mode and an automatic mode, and a remote controller can be used for man-machine interaction. In the automatic mode, KML data of a preset path can be input, the plant protection operation vehicle controller adjusts steering by reading IMU attitude information and GPS satellite positioning information, controls a driving motor to autonomously walk according to the preset path, realizes path tracking by using course tracking, defines traveling path information (KML) by using upper computer control software, and communicates with the operation vehicle controller by using radio or directly stores the KML in the operation vehicle controller. The GPS module installed on the working vehicle receives the satellite positioning signal in real time, the main controller resolves the current positioning information and the defined path information, so as to obtain the target course, control the steering angle and speed, and the path tracking flow is shown in FIG. 14.

In the operation process, the operation vehicle transmits back position and speed information in real time through the wireless communication module, the air route or the driving speed can be checked and modified at a computer or a mobile phone end, the communication mode adopts the MAVLink protocol, and open-source ground station software developed under the protocol can be directly used. A driving motor of the operation vehicle needs a controller to output a PWM signal to control the driving motor to regulate the speed, and the steering motor also needs the controller to use a pulse trigger switch to control a diaphragm pump for opening and closing a spraying system.

The upper computer control software (ground station) adopts open source project software QGroundcontrol, and a radio module is required for communication between the operation vehicle and the ground station. The SiK radio module is a small, lightweight and inexpensive open source radio platform that typically provides a connection range of over 300 meters (using patch antennas, which may extend to several kilometers), and is specifically designed for use with MAVLink packets using open source firmware. The communication frequency may be 915Mhz or 433Mhz, the receiver sensitivity is-121 dBm, the transmit power is up to 20dBm (100mW), and the serial link air data rate is up to 250 kbps.

The controller is ATMEGA2560-16 AU; because of feedback control, the single chip microcomputer needs to continuously calculate data and simultaneously needs to continuously receive attitude sensors and positioning information to perform operation processing on the data, and the single chip microcomputer is required to have higher operation speed and stronger stability.

This embodiment provides a wheel base, height-adjustable's plant protection operation car from this, can carry out the adjustment wheel base and the frame height of adaptability according to the line spacing and the height of the plant of operation, can be applicable to the full-time spraying of plant protection, and the commonality is strong, and control mode adopts remote control, has improved the intelligent degree of plant protection operation, and application scope is wide, and convenient operation has saved the manpower.

Example 2: this example is substantially the same as example 1, except that: the present embodiment further defines the folding structure between the main spray bar 10 and the side spray bar 11.

Folding pieces are arranged between two sides of the main spray rod and the side spray rods, and each folding piece comprises an upper transverse plate 18, a lower transverse rod 19, a middle shaft 20, a clamping seat 21 and a blocking piece 23; the upper transverse plate 18 and the lower transverse rod 19 are respectively arranged at the upper end and the lower end of the main spray rod along the horizontal direction, the upper transverse plate 18 is of a flat plate-shaped structure, the lower transverse rod 19 is of a round rod structure, and the middle shaft 20 vertically penetrates through the upper transverse plate and the lower transverse rod and can rotate; the clamping seat 21 is trapezoidal and fixed on the middle shaft, the bottom of the clamping seat 21 is clamped on the lower cross rod 19, the blocking piece 23 is positioned on the upper part of the middle shaft 20, and the spring 22 is sleeved on the middle shaft and positioned between the blocking piece and the clamping seat.

The embodiment provides a structure of the side spray lance that can manually fold, makes the side spray lance fold on main spray lance, convenient to use, and at fold condition and the gesture that the expansion state homoenergetic remains stable, stable in structure, convenient operation.

Example 3: this example is substantially the same as example 1, except that: the present embodiment further illustrates the height adjustment mechanism.

The clamping grooves are formed in the wheel carriers, corresponding marks are arranged on the clamping grooves, the U-shaped bolts are clamped and fixed in the clamping grooves in the embodiment, the clamping grooves are formed in a mode that the U-shaped bolts slide downwards, stability of the clamp is improved, the clamping grooves in the four wheel carriers are correspondingly formed, the corresponding marks serve as references, accordingly, stability of the frame is guaranteed, and the references are set for height adjustment of the frame.

Example 4: this example is substantially the same as example 1, except that: the present embodiment further describes the structure of the track adjusting mechanism.

As shown in fig. 11, the adjusting rod is provided with a rack 24 on the upper side, the adjusting sleeve is provided with a through hole, a gear 25 is nested in the through hole and meshed with the rack 24, in this embodiment, a structure capable of automatically adjusting the wheel track is provided, the gear is provided with a motor, the motor is in transmission connection with the gear, the gear drives the rack by controlling the rotation of the motor, and therefore the controller controls the steering of the motor to adjust the wheel track.

Claims

1. The utility model provides an electronic plant protection operation car of intelligent driving of height, wheel base adjustable which characterized in that: comprises a front frame, a rear frame, a bowing steering mechanism, a wheel track adjusting mechanism, a height adjusting mechanism and a spray rod mechanism; the front frame and the rear frame are connected through a articulated steering mechanism to form a frame main body, a power supply and a remote control receiver are installed on the front frame, a medicine box, a diaphragm pump and a portal frame are installed on the rear frame, and the wheel track adjusting mechanism is arranged between the movable wheels and the frame; the height adjusting mechanism comprises a connecting seat, a U-shaped bolt and a wheel frame, the connecting seat is fixed on the frame, the U-shaped bolt penetrates through the connecting seat and hoops the wheel frame on the connecting seat, the bottom of the wheel frame is provided with moving wheels, and each moving wheel is provided with a driving motor; the articulated steering mechanism comprises a steering motor, a front steering frame, a rear steering frame, a gear set and a driving shaft, wherein a front steering frame and a rear steering frame are respectively fixed at the joint of the front frame and the rear frame; the steering motor is arranged on a rear steering frame through a bracket, the front steering frame is fixed on a driving shaft, and the rear steering frame is rotatably arranged at two ends of the driving shaft; the steering motor is in transmission connection with the driving shaft through a gear set, so that the front bogie can rotate relative to the rear bogie under the driving of the steering motor; the spray rod mechanism comprises a lifting frame, side wheels, an electric push rod, a main spray rod and side spray rods; the electric push rod is arranged between the lifting frame and the portal frame and used for driving the lifting frame to lift along the portal frame; the main spray rod is fixed on the lifting frame, and the side spray rod is arranged on the main spray rod in a folding mode.

2. The intelligent driving electric plant protection working vehicle with adjustable height and wheel track according to claim 1, characterized in that: the gear set comprises a driving gear, a driven gear, a sleeving gear and a driving gear; a rotating shaft of the steering motor is sleeved with a driving gear, the driving gear is meshed with a driven gear, a sleeving gear is coaxially sleeved at the lower part of the driven gear, and the driving gear is meshed with the sleeving gear; the lower part of the driving gear is fixedly sleeved on the upper part of the driving shaft.

3. The intelligent driving electric plant protection working vehicle with adjustable height and wheel track according to claim 1, characterized in that: folding pieces are arranged between two sides of the main spray rod and the side spray rods, and each folding piece comprises an upper transverse plate, a lower transverse rod, a middle shaft, a clamping seat and a blocking piece; the upper transverse plate and the lower cross rod are respectively arranged at the upper end and the lower end of the main spray rod along the horizontal direction, and the middle shaft vertically penetrates through the upper transverse plate and the lower cross rod and can rotate; the clamping seat is in a trapezoidal structure, the clamping seat is fixed on the middle shaft, the bottom of the clamping seat is clamped on the circular tubular lower cross rod, the blocking piece is positioned on the upper portion of the middle shaft, and the spring is sleeved on the middle shaft and positioned between the blocking piece and the clamping seat.

4. The intelligent driving electric plant protection working vehicle with adjustable height and wheel track according to claim 1, characterized in that: the wheel track adjusting mechanism comprises an adjusting sleeve, an adjusting rod and a limiting bolt; the adjusting sleeve is fixed on the front frame, the adjusting rod is sleeved in the adjusting sleeve, and the adjusting sleeve and the adjusting rod are respectively provided with a fixing hole and a plurality of positioning holes; the limiting bolt is adjusted in the fixing hole and the positioning hole to keep the positions of the adjusting rod and the adjusting sleeve.

5. The intelligent driving electric plant protection working vehicle with adjustable height and wheel track according to claim 1, characterized in that: the wheel carrier is provided with a clamping groove, the clamping groove is correspondingly marked with scales, and the U-shaped bolt is matched and clamped in the clamping groove.

6. The intelligent driving electric plant protection working vehicle with adjustable height and wheel track according to claim 1, characterized in that: the control system comprises an attitude sensor, an upper computer, a controller, a diaphragm pump, a driving motor and a steering motor; the plant protection vehicle comprises a plant protection vehicle body, an attitude sensor, an upper computer, a diaphragm pump, a driving motor, a steering motor, a controller and a host computer, wherein the attitude sensor is used for receiving vehicle condition information of the plant protection vehicle and uploading the vehicle condition information to the controller, the host computer sends an instruction to the controller through the wireless module, and the signal output end of the controller respectively controls the diaphragm pump, the driving motor and the steering motor to work so as to adjust the spraying power, the vehicle speed and the steering of the.