CN102707730A - Hydraulic aerial cage operation platform trajectory control device - Google Patents

Abstract

The invention discloses a hydraulic aerial cage operation platform trajectory control device. The control device comprises an operation mechanism (A), a detection device (B), a display and alarm device (C), a hydraulic operation loop (D) with pressure compensation, a coordinate location module (E), a forward resolving module (F), a deflection compensation module (G), a speed setting module (H), an algorithm optimization module (I), and a programmable controller (J). The control device provided by the invention can significantly improve the work efficiency of the hydraulic aerial cage, reduce the labor intensity of operators, and lower the energy consumption as well as the use cost.

Description

Trajectory control device for operating platform of aerial work vehicle

technical field

The invention relates to the field of high-altitude operation equipment with variable amplitude telescopic arms, in particular to a control device for an operation platform of an aerial work vehicle.

Background technique

The aerial work vehicle is a special engineering vehicle used to transport staff and equipment to a designated height for operations. The operating platform is a device for the work vehicle to carry staff and equipment in the air. The application object of the present invention is a straight-arm aerial work vehicle with a telescopic mechanism. The boom is driven by oil cylinders installed on the turntable and the boom at both ends to drive the luffing. The telescopic mechanism (such as rope row, sprocket, etc. etc.) to achieve.

When the aerial work vehicle scrubs the glass up and down along the walls of high-rise buildings or installs objects sequentially along the top wall, or quickly reaches the designated operating point, the operator needs to continuously operate the luffing and telescopic handles in order to make the operating platform move according to the desired trajectory. For this typical "open loop" motion control method, the operator is required to have high operating skills. And relying only on the operator's vision, it is very difficult and difficult to reproduce the platform along the desired trajectory. On the contrary, the "closed-loop" motion control system of the present invention uses the long-angle sensor installed on the boom and the length sensor on the oil cylinder to detect, and through the calculation of the controller, the operation platform can accurately move along the planned trajectory and can be repeated. For example, moving up and down along the wall or moving along the top of the wall.

The application and development of electronic and hydraulic technology in engineering machinery has enabled trajectory control to be applied in various engineering equipment. At present, control systems capable of operating according to the set trajectory have appeared on concrete pump trucks, excavators, loaders, crawler cranes, boom tower cranes, forklifts and other equipment, and many patents have been applied for.

On the high-altitude vehicle, using the controller, the motion control that has been realized has the following aspects:

(1) Use the level sensor of the working platform to perform real-time leveling of the platform.

(2) Use the boom length angle sensor to control the telescopic and lifting of the boom, so that the equipment can work within the safe operating range. At the same time, after receiving the sensor signal, the controller limits the vehicle's walking speed according to different boom conditions.

(3) Use the level sensor of the turntable to detect the inclination angle of the whole machine and limit the action of the corresponding mechanism.

(4) Use the platform load sensor to limit the platform load to no more than the rated load to ensure the stability of the whole machine.

The above sensors belong to the equipment that usually must be installed on high-altitude vehicles. The controller receives the sensor signal and makes corresponding control instructions according to the compiled program. However, the above-mentioned motion control is limited to specific points or local restrictive actions, and the present invention realizes a continuous track control.

The following contents are patents and documents similar to the protection content of this patent, but there are obvious differences and are summarized as follows:

The patent application number is 201110027467.1, and the title is "A Method for Controlling the Working Trajectory of an Aerial Work Platform", which introduces a method for controlling the working trajectory of an aerial work platform using six steps. The patent introduces the selected control components and their functions. In the patent algorithm, it is introduced to collect signals through various sensors, and the actual required length and angle are calculated by the controller. But there are the following technical issues:

(1) The patented control algorithm is not fully disclosed. Although the patent gives the concept of error compensation, it is unclear on the specific compensation of using the difference between the target value and the state value through the controller to act on the proportional valve with a PWM signal. Specifically, there are the following four problems: First, the PWM signal in this patent acts on the proportional valve, and the proportional valve is a nonlinear link in the entire control, that is, the output flow of the proportional valve will not be proportional to the control current PWM value, Therefore, the maximum and minimum currents of the proportional valve are only measured through experiments. No matter how the PWM signal is adjusted, the control requirements described in the article will not be met, error compensation cannot be realized, and the control function cannot be realized; Theoretically, in the position control type I system of a typical valve-controlled cylinder with only negative feedback, when the signal after the trigonometric function operation is used as an input command, the execution system will generate a steady-state error, and the full compensation of the error cannot be realized; The third is that in realizing the ideal vertical lift and horizontal telescopic movement described in this patent, no rotation angle is involved in the calculation. Fourth, the patent does not clearly provide the mathematical operation relationship between the slewing angle, the boom angle, and the luffing angle.

(2) There are potential safety hazards in the implementation of this patent. As a device for lifting personnel to work in the air, ensuring the safety of the operator is the first priority. The horizontal slewing action carried out in this paper only considers the slewing, luffing and telescoping of the working arm, but ignores the slewing control of the manned operating platform. When implementing the horizontal rotation described in this patent, only the horizontal rotation of the arm head of the working arm is realized according to the patent, while the operating platform forms an angle with the horizontal rotation plane of the arm head during this movement, so that the operation at the end of the boom The platform does not swivel horizontally as the designer intended. The result of this control may cause the operation platform to collide with adjacent high-altitude objects, which not only causes equipment damage, but even endangers the life safety of operators, resulting in safety accidents.

(3) The patent lacks the integrity of the motion control elements described. The jib of the aerial work vehicle is often composed of several sections of the jib. Due to the self-weight of the boom, the load of the platform and the gap between the booms, the boom will have obvious deflection deformation. As the length of the boom increases, the deflection deformation will become more significant, seriously affecting the position control effect described in this patent. The deflection deformation is not involved in this patent, nor is a solution proposed.

The document "Motion control of an aerial work platform" describes a motion control method for aerial work platforms. This document uses advanced mechanics to convert control and detection parameters in Cartesian coordinate system, joint coordinate system and execution space coordinate system, which involves complex theory and requires high operation speed and control accuracy of control system components. Therefore, this document A specific high-end controller has been selected in the control system, making this control method expensive. This kind of complex calculation control method cannot be realized on the current general-purpose controller of aerial work vehicles. This patent simplifies the model and uses plane analytic geometry to solve it, which simply and effectively realizes the trajectory control function, which can be realized on the current common controller of aerial work vehicles.

The document "Level luffing control system for crawler crane" describes a method of horizontal luffing control for crawler cranes. The control system proposed in this document is suitable for crawler cranes, and its control objects are luffing motors and hoisting motors. This document mainly proposes and solves four problems: the swing of the boom due to insufficient stiffness, the nonlinearity of the actuator, the difference in control characteristics due to the hoisting load and the engine speed, and the large error at the moment of starting.

In order to solve the problem of swing caused by the stiffness of the boom, the literature only adopts the compound correction method of feedforward and feedback, while this patent adopts different correction methods for each link. In order to solve the nonlinear problem of linear components, the literature uses electrical signal control compensation measures, but this patent uses a proportional valve component with pressure compensation to solve it. After the document, the two problems will not appear on the implementation object of this patent.

The patent application number is 06119983.2, and the name is "Articulated ladder or raisable platform position path control and active vibration damping", which describes the path control and vibration suppression of an articulated ladder or lifting platform. This patent uses a variety of sensors to collect signals and input them into the controller for calculation, so as to realize the accuracy of the individual mechanism during the movement and suppress the vibration during the movement. This patent only realizes the stability control of the action of a single mechanism, and does not implement the compound action control of the mechanism, and cannot realize the control of the operating platform along a specific linear trajectory.

Contents of the invention

(1) Purpose of the invention

The object of the present invention is to realize the specific linear trajectory motion of vertical lifting, horizontal expansion and horizontal rotation of the aerial work vehicle operating platform.

(2) Technical solution

a) Function buttons and operating handles

Function buttons include enabling button, motion learning button and recurring motion button.

Set the enable button on the control panel to facilitate the mutual switching between normal operation and the intelligent operation. When the enable button is in the normal position, the handle on the operation control surface is a normal operation function. When you need to use the track to control the smart operation, you must first press the button and hold it, the handle on the control panel switches to the smart operation mode and shields the normal operation function of the handle.

There is a motion learning button in the control panel. When the enable button is pressed and held, the button is activated, and the controller can memorize the motion parameters (path, speed) of the aerial work vehicle during this period of time and store them.

The control panel is equipped with a motion replay button. When the enable button is pressed and held, the button is activated, and the aerial work vehicle will reproduce the last stored motion until the button or the enable button is not activated. The action stops now.

In intelligent trajectory control, two dual-axis proportional handles are used. The up and down movement of the first operating handle means performing the vertical lift function as shown in Figure 1, and the left and right movement of the operating handle means performing the horizontal telescopic function as shown in Figure 2. The left and right movement of the second operating handle indicates that the horizontal rotation function is performed as shown in Figure 3, and the up and down operation functions are shielded.

b) sensor

In order to detect the status of the equipment boom, the long angle sensor is used to detect the length and angle of the boom, the length sensor is used to detect the length of the luffing cylinder, the turntable encoder is used to detect the rotation angle of the turntable relative to the disembarkation, and the platform encoder is used to detect the relative position of the operating platform. The swivel angle of the boom. The measured value will be passed to the programmable controller for calculation.

c) Display alarm device

The display device can automatically select the set operating range according to the current status of the whole machine, and highlight it on the display screen, which is beneficial for the operator to clarify the operating range. The alarm device is composed of an indicator light and a buzzer, and makes corresponding actions according to the control instructions of the controller. When the track control enable button is pressed, the indicator light flashes. Press the trajectory control enable button and operate the handle to let the platform move according to a specific trajectory, the indicator light will be constant, the buzzer will emit a corresponding prompt sound, and the ideal trajectory will be displayed on the display device.

d) Hydraulic working circuit with pressure compensation

The turntable valve group includes three circuits of luffing, telescopic and rotary. The main valve of each circuit is equipped with pressure compensation, so that the flow that drives the cylinder or motor is only related to the opening of the main valve, that is, it is approximately linear with the current of the main valve. Proportional relationship, regardless of the driving load. At the same time, the three control loops of stretching, luffing and turning do not interfere with each other, as shown in Figure 4.

The platform valve group includes platform swing and platform leveling circuits. The main valve of each circuit has pressure compensation, so that the flow that drives the leveling cylinder or the swing motor is only related to the opening of the main valve, that is, it is similar to the current of the main valve. Linear proportional relationship, independent of the driving load. At the same time, the two control loops of leveling and swing do not interfere with each other, as shown in Figure 5.

e) Coordinate positioning module

This module has the function of detecting the current state of the main arm and judging whether to allow intelligent operation. When the intelligent trajectory control is started, the module receives the signal of the boom length angle sensor to determine the boom angle and the length of the boom; receives the signal of the turntable encoder to determine the rotation angle of the turntable, that is, the rotation angle of the boom relative to the disembarkation; the receiving platform The encoder signal determines the rotation angle of the operating platform relative to the boom.

In the XY plane, the controller calculates the position of the end of the boom, compares it with the equipment operating range shown in Figure 6, and makes an intelligent operation judgment on whether it can be lifted vertically or stretched horizontally. When it is detected that the end of the boom is located in the envelope of the working area and its adjacent area, it is allowed to perform one action of vertical lifting or lowering and one action of horizontal extension or retraction. When the operator pushes the handle to perform an impermissible action, the alarm buzzer warns and the whole machine does not move.

In the XZ plane, the controller calculates the rotation angle of the boom relative to the positive direction of getting off the vehicle and the rotation angle of the operating platform relative to the boom, and saves the current state parameters of the boom and the operating platform.

The speed priority of the intelligent trajectory operation is lower than the operating speed specified in the working area. The controller receives the detection signal transmitted by the module in real time and compares it with the setting program. When the intelligent trajectory operation is close to the envelope of the working area or other restricted points, the alarm device will prompt the operator; when the intelligent trajectory operation is close to the envelope of the operating area or other restricted points, the intelligent trajectory operation will be restricted, and the alarm device will beep to alarm.

f) Forward solution module

This module carries out the trajectory calculation of the motion path of the ideal state operation platform. The module works after the coordinate positioning module judges that the intelligent trajectory operation can be performed, and receives the boom, turntable and operating platform state parameters and handle operation signals detected by the coordinate positioning module.

When the module calculates vertical lifting and horizontal telescoping, it takes the boom angle as the main input reference quantity, and outputs ideal control signals for respectively controlling the movements of the luffing cylinder and the telescopic cylinder.

When the module calculates the horizontal rotation, it takes the rotation angle of the turntable as the main input reference quantity, and outputs the ideal control signals that respectively control the movement of the turntable rotary motor, luffing cylinder, telescopic cylinder and swing motor of the operating platform.

In the simplified vertical lifting diagram shown in Figure 7, to ensure that the projected length of the boom OC on the horizontal X-axis remains constant during the movement, the following calculations are performed:

                                              (1)

(1)

                                           (2)

(2)

In the simplified diagram of horizontal stretching shown in Figure 8, to ensure that the projected length of the boom OC on the vertical Y-axis remains constant during the movement, the following calculations are performed:

                                              (3)

(3)

                                          (4)

(4)

和沿X轴投影长度

均保持恒定，结合图7和图8，进行如下计算： In the simplified diagram of horizontal rotation shown in Figure 9, it is ensured that the projection of the boom OC in the XY plane remains constant during the movement, that is, the projected length along the Y axis

and the projected length along the X axis

are kept constant, combined with Figure 7 and Figure 8, the following calculations are performed:

                                                 (5)

(5)

(6)

                                          (7)

(7)

                                                (8)

(8)

                                       (9)

(9)

(10)

Use the sensor to compare the actual length with the calculated length, and the rotation angle with the calculated angle, and import the difference between the two into the loop for calculation, and calculate the control errors of the control loops of variable amplitude, telescopic, turntable rotation, and platform swing as follows:

                                             (11)

(11)

(12)

                                             (13)

(13)

                                               (14)

(14)

                                               (15)

(15)

为臂架长度误差，

为臂架实际长度，

为臂架伸缩油缸长度误差，

为臂架长度变化量与臂架伸缩油缸长度变化量的比值，

为臂架变幅油缸长度误差，

为臂架变幅油缸实际长度，为转台回转角度误差，

为转台回转实际角度，

为平台摆动角度误差，

为平台实际摆动角度。 In the formula:

is the jib length error,

is the actual length of the boom,

is the length error of the boom telescopic cylinder,

is the ratio of the length change of the boom to the length change of the boom telescopic cylinder,

is the length error of the jib luffing cylinder,

is the actual length of the jib luffing cylinder, is the rotation angle error of the turntable,

is the actual rotation angle of the turntable,

is the platform swing angle error,

is the actual swing angle of the platform.

g) Deflection compensation module

。 This module calculates the fixed deflection and deformation of the boom due to its own weight and platform load, and adds this deformation to the action signal of the control cylinder to correct the trajectory error caused by the deflection and deformation. At the same time, a correction factor is added to the module, which is used to correct the deformation caused by the gap between the sliders in the lap of the boom and the processing quality of the boom. As shown in Figure 10 of the boom deflection deformation, this module calculates the deflection compensation amount of the boom luffing angle under different boom states

.

According to the simplified diagram of the deflection deformation of the boom shown in Figure 10, the bending deformation and angle compensation values of the boom are obtained by the superposition method as follows:

(16)

                              (17)

(17)

h) Speed setting link

： The national standard "GB/T 9465-2008 Aerial Work Vehicle" stipulates that the lifting and lowering speed of the working platform shall not exceed 0.4m/s, and the horizontal linear velocity of the outermost edge of the platform shall not exceed 0.7m/s in the maximum range. Now use the above two values to calculate the main input reference quantity of the system—the jib luffing angle signal

:

In the simplified diagram of the vertical lift shown in Figure 7:

                                     (18)

(18)

Deriving both sides of formula (18) with respect to time respectively, the following formula is obtained

                                  (19)

(19)

,解微分方程，求平台0.4

匀速升降时，变幅角度

为： with initial conditions

, Solve the differential equation, find the platform 0.4

When lifting at a constant speed, the luffing angle

for:

                            (20)

(20)

In the simplified diagram of horizontal scaling shown in Figure 8:

(twenty one)

Deriving both sides of formula (21) with respect to time respectively, the following formula is obtained

                                   (22)

(twenty two)

,

解微分方程，求平台0.7

匀速伸缩时，变幅角度为： with initial conditions

,

Solve the differential equation and find the platform 0.7

When stretching at a constant speed, the luffing angle for:

                          (23)

(twenty three)

In the simplified diagram of horizontal rotation as shown in Figure 9:

                                        (24)

(twenty four)

Deriving both sides of formula (24) with respect to time respectively, the following formula is obtained

                                    (25)

(25)

,

解微分方程，求臂架末端0.7匀速回转时，回转角度

为： with initial conditions

,

Solve the differential equation to find 0.7 at the end of the boom When rotating at a constant speed, the rotation angle

for:

                              (26)

(26)

为： At this time, in order to keep the operating platform in the same direction relative to getting off the vehicle, it should rotate in the opposite direction at a constant speed, and the swing angle

for:

                          (27)

(27)

i) Algorithm optimization module

This module is embodied in the closed-loop control loop of the intelligent trajectory. The actions of the luffing cylinder, the telescopic cylinder, the rotary motor of the turntable, and the swing motor of the platform are all closed-loop control systems with position feedback. The response performance and stability of the control system will affect the intelligent trajectory. The control effect is related to the comfort and safety of the operator on the platform, and directly affects the practicability of intelligent control. By adding a control algorithm, the trajectory control action is rapid and stable, and the steady-state error is eliminated to ensure good trajectory control performance.

i.1 Composite correction of negative feedback and feedforward: compare the measured values of the luffing cylinder, the telescopic cylinder, the rotary motor of the turntable, and the swing motor of the platform with the calculated values of the controller, such as formulas (11), (12), (13 ), (14), (15). At the same time, the signal input feedforward path is added to form a combined feedforward and feedback control system, which greatly reduces the steady-state error and forms a compound correction;

i.2 PID control link: add PID between the control signal and the main valve, and use its proportional, integral and differential functions;

i.3 Add a PID control algorithm with a dead zone to the telescopic loop.

Boom telescoping is usually driven by the boom telescopic oil cylinder to drive the telescopic mechanism. Moreover, the length-to-diameter ratio and the bore-to-bore ratio of the telescopic oil cylinder are relatively large, so the response frequency of the telescopic mechanism is low, thereby increasing the difficulty of control.

In vertical lift mode, the boom length changes from shortening to lengthening as the boom luffs through the horizontal position. In vertical descent mode, the jib length changes from extending to shortening as the jib traverses the horizontal position. The closer the boom is to the horizontal position, the smaller the change in the length of the boom, and the higher the requirement for position control accuracy. And for the valve-controlled asymmetrical cylinder, because the quick changeover will cause a pressure jump, causing the "inside explosion" or "outside explosion" of the oil, so that it cannot work smoothly during the changeover.

In order to prevent the telescoping mechanism from changing direction rapidly when the jib swings through the level, eliminate the oscillation caused by the rapid direction changing action, and at the same time reasonably reduce the position control accuracy, a PID control with a dead zone is adopted, as shown in Figure 11. The flowchart of the PID control algorithm with dead zone is shown in Figure 12, and its control formula is as follows:

                                    (28)

(28)

是一个可调的参数，具体数值可根据具体设备由现场实验确定。 In the formula, the dead zone

It is an adjustable parameter, and the specific value can be determined by field experiments according to specific equipment.

According to the algorithm derivation of each module in the trajectory control component, the flow of the linear trajectory control system is shown in Figure 13.

j) Programmable controller

At present, the aerial work vehicle generally adopts an electro-hydraulic control system. The programmable controller in the system makes a logical judgment according to the command signal input by the operator, and controls the solenoid valve to realize the motion control of the whole vehicle. At the same time, the controller can receive various sensor data, analyze and calculate, and make corresponding judgments. The programmable controller receives the signal generated by the trajectory control module consisting of four parts: coordinate positioning, forward solution, deflection compensation, speed setting and algorithm optimization, and uses programming to realize the algorithm of each module in the trajectory control component. Figure 14 is a diagram of data transmission between the programmable controller and the actuator and sensing device of the high-altitude vehicle.

When performing vertical lifting or horizontal telescoping, the boom luffing angle is used as the unified input variable, and at the same time, a control current is generated to act on the solenoid valve and alarm device of the luffing and telescopic hydraulic working circuit. The control operation is shown in Figure 15.

When performing horizontal rotation, the rotation angle of the turntable is used as the unified input variable, and at the same time, a control current is generated to act on the solenoid valve and the alarm device of the hydraulic working circuit of the luffing, telescopic, turntable rotation and operation platform swing, and its control operation is shown in Figure 16. Show.

(3) Beneficial effects

The use of this device can significantly improve the working efficiency of the aerial work vehicle, reduce the labor intensity of operators, reduce energy consumption, and reduce the use cost.

Description of drawings

Figure 1 is a schematic diagram of the vertical lift of the aerial work vehicle.

Figure 2 is a schematic diagram of the horizontal expansion and contraction of the aerial work vehicle.

Figure 3 is a schematic diagram of the horizontal rotation of the aerial work vehicle.

Figure 4 is a hydraulic schematic diagram of the turntable valve group.

Figure 5 is a hydraulic schematic diagram of the platform valve group.

Figure 6 is a diagram of the working interval of the high-altitude vehicle.

Figure 7 is a simplified diagram of the vertical lift.

Figure 8 is a simplified diagram of horizontal scaling.

Figure 9 is a simplified diagram of horizontal rotation.

Figure 10 is a simplified diagram of the deflection deformation of the boom.

Figure 11 is a diagram of a PID control system with a dead zone.

Figure 12 is a block diagram of the PID control algorithm with a dead zone.

Figure 13 is a flow chart of the trajectory control system.

Figure 14 is a data transmission diagram of the trajectory control system.

Fig. 15 is a control operation diagram of vertical lifting and horizontal telescoping.

Fig. 16 is a diagram of horizontal rotation control operation.

The reference signs are explained as follows:

1. Get off the car; 2. Turntable (built-in hydraulic system and electrical system); 3. Luffing cylinder (installed with displacement sensor); 4. Telescopic cylinder (built-in, connected to the first and second sections of the boom); 5. Arm Frame assembly; 6. Long angle sensor; 7. Working platform.

— 臂架伸缩后长度，即图7和图8的，图9中的

；

— The length of the boom after stretching, that is, the length in Figure 7 and Figure 8 , in Figure 9

;

— 臂架初始状态长度，即图7、图8和图9中的

；

— The length of the initial state of the boom, that is, the length in Fig. 7, Fig. 8 and Fig. 9

;

— 操作平台中轴线简化示意；

— Simplified representation of the central axis of the operating platform;

的夹角； — In the initial state, the jib and

the included angle;

 —

与X轴正方向之间的夹角；

—

The included angle with the positive direction of the X axis;

 — 初始状态时，臂架

与XZ平面之间的夹角；

— In the initial state, the boom

The included angle with the XZ plane;

 — 初始状态时，臂架

在XZ平面内投影OD与X轴正方向之间的夹角；

— In the initial state, the boom

The angle between the projection OD and the positive direction of the X axis in the XZ plane;

 — 初始状态时，操作平台中轴线与臂架在XZ平面内投影之间的夹角；

— In the initial state, the central axis of the operating platform with jib The angle between the projections in the XZ plane;

 — 臂架伸缩后，臂架与

的夹角；

— After the boom stretches, the boom and

the included angle;

； — After the boom is stretched, the length of the luffing cylinder, that is, the length in Figure 7 and Figure 8

;

 — 臂架伸缩后，臂架

与XZ平面之间的夹角；

— After the boom stretches, the boom

The included angle with the XZ plane;

 — 臂架伸缩后，臂架在XZ平面内投影OD与X轴正方向之间的夹角；

— After the boom stretches, the boom The angle between the projection OD and the positive direction of the X axis in the XZ plane;

 — 臂架伸缩后，操作平台中轴线

与臂架

在XZ平面内投影之间的夹角；

— After the boom is retracted, the central axis of the operating platform

with jib

The angle between the projections in the XZ plane;

 — 变幅油缸根铰点与臂架根铰点之间距离，即图7和图8中的；

— The distance between the root hinge point of the luffing cylinder and the root hinge point of the jib, that is, the distance in Figure 7 and Figure 8 ;

— The distance between the end hinge point of the luffing cylinder and the root hinge point of the jib, that is, in Fig. 7 and Fig. 8 ;

— 臂架端部点沿Y轴方向运动的位移；

— Boom end The displacement of the point moving along the Y axis;

— 臂架端部

点距X轴方向运动的位移；

— Boom end

The displacement of the point from the movement in the X-axis direction;

— 臂架端部

点距Z轴方向运动的位移；

— Boom end

The displacement of the point from the Z-axis direction movement;

 — 臂架端部最大挠度；

— the maximum deflection at the end of the jib;

 —修正因子；

- correction factor;

 — 臂架质量线密度；

— jib mass linear density;

 — 臂架材料弹性模量；

— Elastic modulus of boom material;

 — 臂架当量截面惯性矩；

— jib equivalent section moment of inertia;

— platform component quality;

 —臂架与X轴线的夹角；

— Angle between the boom and the X-axis;

 —臂架变幅角度挠度补偿量。

—Amount of deflection compensation for jib luffing angle.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

The track control device of the aerial work vehicle of the present embodiment includes the following parts:

1. Operating mechanism

1.1 Self-reset trajectory control enable button: the circuit is not connected under normal conditions, and the device is controlled by normal operation at this time. When the button is pressed, the intelligent trajectory control is enabled, and the normal normal operation control is blocked at the same time.

1.2 The three-position rocker switch is used as a movement learning button and a movement reproduction button. On the premise that the self-resetting trajectory control enable button is pressed and held, the rocker switch is pressed to the upper position to start the motion learning function, and the controller can memorize the motion parameters (path, speed) of the aerial work vehicle during this period of time and store them . On the premise that the reset trajectory control enable button is pressed and held, the rocker switch is in the normal position, the memory is stopped, and the previously memorized motion parameters are saved at the same time. On the premise that the self-resetting trajectory control enable button is pressed and held, the rocker switch is pressed down to start the recurring motion function, and the aerial work vehicle will reproduce the last stored motion until the rocker switch is not in the down position or is used The function button is not activated, and the reproducible action stops.

1.3 Dual-axis proportional handle: During normal operation, the up and down push handle of the first operating handle is for luffing up and luffing down, and the left and right push handle is for boom extension and boom retraction. The left and right movement of the second operating handle indicates that the ordinary turntable rotation work is performed. When the self-resetting trajectory control enabling button is pressed, the up and down movement of the first operating handle indicates the vertical lift function as shown in Figure 1, and the left and right movement of the operating handle indicates the horizontal telescopic function as shown in Figure 2. The left and right movement of the second operating handle indicates that the horizontal rotation function is performed as shown in Figure 3, and the up and down operation functions are shielded.

2. Display and alarm device

2.1 Display screen: According to the current status of the whole machine, the set operation area is automatically selected and highlighted on the display screen, which is helpful for the operator to clarify the operation range. Press the self-resetting trajectory control enable button and operate the handle to make the platform move according to a specific trajectory, and the ideal trajectory will be displayed on the display.

2.2 Buzzer: Press the self-resetting trajectory control enable button and operate the handle to make the platform move according to a specific trajectory, and the buzzer will emit a corresponding prompt sound.

2.3 Yellow indicator light: When the self-resetting track control enable button is pressed, the yellow indicator light flashes. When the self-resetting trajectory control enabling button is pressed and the handle is operated to make the platform move according to a specific trajectory, the yellow indicator light is constant.

3. Detection device

3.1 Long-angle sensor: The long-angle sensor is used to measure the length and angle of the boom. There is a proportional relationship between the length of the boom and the stroke of the telescopic cylinder of the boom. In this embodiment, the maximum stroke of the telescopic oil cylinder of the boom is 8m, and the angle range of the boom is -12°~80°. A long-angle sensor with an effective measurement length of 11.5m and an effective measurement angle of 320° is selected, and the corresponding output current value range is 4-20mA.

3.2 Length sensor: This sensor measures the length of the jib luffing cylinder. In this embodiment, the stroke of the luffing oil cylinder is 1.9m, and a length sensor with an effective measurement length of 2.5m is selected, and its corresponding output current range is 4-20mA.

3.3 Encoder: This encoder is generally used to measure the rotation angle of the turntable and the swing angle of the operating platform. In this embodiment, the turntable can perform continuous 360° rotation, and a multi-turn absolute encoder is selected, and the corresponding output current range is 4-20mA. The operating platform can swing left and right by 90°, and a single-turn absolute value encoder is selected, and the corresponding output current range is 4-20mA.

4. Hydraulic drive valve group

A proportional flow cartridge valve with pressure compensation is adopted. The valve is a cartridge-type electromagnetic drive valve, which is normally closed when the power is off. The flow rate at the output port is not affected by the working pressure of the system. The output flow increases. Both the luffing and telescopic main valves have a coil voltage of 24V, a threshold current of 175±50mA, a maximum control current of 800±100mA, and a maximum flow rate of 53L/min.

5. Coordinate positioning

In the embodiment, when the self-resetting trajectory control enabling button is pressed, the coordinate positioning module first detects the current state of the main arm and judges whether to allow intelligent operation after receiving the sensor signal. Based on the working interval shown in Figure 6, the following judgments are made:

1) When the current state of the jib is within the envelope line Ⅰ of the operating area and its vicinity, horizontal extension and vertical lifting can be performed within the operating area, but horizontal retraction and vertical landing are not allowed;

2) When the current state of the jib is within the envelope II of the operating area and its vicinity, horizontal extension and vertical landing can be performed within the operating area, but horizontal retraction and vertical lifting are not allowed;

3) When the current state of the jib is within the envelope line III of the operating area and its vicinity, horizontal retraction and vertical landing can be performed within the operating area, but horizontal extension and vertical lifting are not allowed;

4) When the current state of the jib is within the envelope line IV of the operating area and its vicinity, horizontal extension and vertical lifting can be performed within the operating area, but horizontal retraction and vertical landing are not allowed;

5) When the current state of the boom is inside all the envelopes of the working area, the expected intelligent trajectory operation can be performed in the working area.

In this embodiment, the jib is a box-shaped section with a telescopic mechanism, the root of the jib is hinged on the turntable, the middle of the jib is connected to the luffing cylinder, and the end of the jib carries a platform of a certain mass.

The three initial states of the equipment were used to verify the vertical lift, horizontal retraction and horizontal slewing performances in trajectory control.

In vertical lifting, the initial state is that the angle between the boom and the X-axis is 0°, and the initial length of the boom is 15m. At this time, the projection of the boom on the X-axis is 15m. In the terminal state, the angle between the boom and the X-axis is 61.79°, the length of the jib is 31.76m after it is extended, and the projection of the jib on the X axis is 15.01m. It shows that during the lifting process of the platform, the vertical effect is better maintained.

In horizontal retraction, the initial state is that the angle between the boom and the X-axis is 60°, and the initial length of the boom is 26.0m. At this time, the projection of the boom on the Y-axis is 22.52m. In the end state, the angle between the boom and the X-axis It is 76.77°, and the length of the jib is 23.11m after retracting. At this time, the projection of the jib on the Y axis is 22.5m. It shows that in the process of retracting the platform, the horizontal effect is better maintained.

In the horizontal rotation, the initial state is that the angle between the projection of the boom in the XZ plane and the positive direction of X is 25°, the angle between the boom and the XZ plane is 45°, the initial length of the boom is 20.0m, the operating platform and the boom clamp The angle is -25°. At this time, the boom is projected on the XY axis, the projected length along the Y axis is 14.14m, and the projected length along the X axis is 12.82m. In the terminal state, the angle between the projection of the boom in the XZ plane and the positive direction of X is -25°. At this time, the angle between the boom and the XZ plane is 45.07°, the length of the boom is 20.04m, and the angle between the operating platform and the boom is 25° °. It shows that in the process of platform rotation, the horizontal effect is better maintained.

In summary, the trajectory control device has the following characteristics:

1. Make full use of the components on the original high-altitude vehicle equipment, and there are not many additional components to purchase;

2. Equipped with a normal operation and intelligent operation switching device, which is convenient for switching between the two operation modes without interfering with each other;

3. In the vertical lifting and horizontal telescopic, the luffing angle of the boom is used as the unified input value, and the synchronous control of the luffing cylinder and the telescopic cylinder can achieve high control accuracy, and the control loops of the two cylinders have no interaction;

4. In the horizontal rotation, the rotary angle of the turntable is used as the unified input value, and the synchronous control of the rotary motor, swing motor, luffing cylinder and telescopic cylinder can achieve high control accuracy, and the four control loops have no interaction;

5. In the position control system of each mechanism, different algorithms are used for correction, so as to effectively achieve a fast and stable response and achieve the trajectory control requirements;

6. Add deflection and deformation compensation and adjust the compensation factor to make the control track adapt to booms of different telescopic lengths;

7. It is easy to operate, reduces the proficiency requirements for operators, and reduces the work intensity of workers;

8. Due to the ability to stabilize and reproduce trajectory movements, it can significantly save working time and improve work efficiency, thereby reducing equipment operating costs and significantly enhancing the competitiveness of equipment in similar markets.

The above content is a further detailed description of the present invention in combination with preferred technical solutions, and it cannot be assumed that the specific implementation of the invention is limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, simple deduction and substitutions can be made without departing from the concept of the present invention, which should be regarded as the protection scope of the present invention.

Claims (1)

1. An aerial work vehicle operating platform track control device, characterized in that, the aerial work vehicle operating platform track control device comprises the following parts: A． operating mechanism The operating mechanism part is a control panel provided with function buttons and operating handles; The function buttons include an enabling button, a motion learning button and a recurring motion button; The enable button is used to switch between normal operation and intelligent operation; when the enable button is in the normal position, the operating handle on the operation control surface is for ordinary operation; Press and hold the button, the operating handle on the control panel switches to the smart operation mode and shields the normal operating functions of the operating handle; The motion learning button, when the enable button is pressed and held, starts the motion learning button, and the programmable controller memorizes the motion parameters of the aerial work vehicle during this period of time and stores them; The recurring motion button, when the enabling button is pressed and held, the recurring motion button is activated, and the aerial work vehicle will reproduce the last stored motion until the reproducing motion button or the enabling button is not activated, Recurrence stops; When using trajectory control intelligent operation, two dual-axis proportional handles are selected; the up and down movement of the first operating handle indicates the vertical lifting function, the left and right movement of the first operating handle indicates the horizontal telescopic function; the left and right movement of the second operating handle indicates the horizontal Swivel function, up and down operation function is shielded; B． Detection device The detection device uses a long-angle sensor to detect the length of the boom and the angle of the boom, a length sensor to detect the length of the luffing oil cylinder, a turntable encoder to detect the rotation angle of the turntable relative to the disembarkation, and a platform encoder to detect the position of the operating platform relative to the boom. Rotation angle; each measured value will be transmitted to the programmable controller for calculation; C． Display and alarm device According to the current state of the whole machine, the display device automatically selects the set operation range and highlights it on the display screen, which is beneficial for the operator to clarify the operation range; The alarm device is composed of an indicator light and a buzzer, and makes corresponding actions according to the control instructions of the controller; when the track control enable button is pressed, the indicator light flashes; press the track control enable button and operate the handle to let the platform When moving according to a specific trajectory, the indicator light remains constant, the buzzer emits a corresponding prompt sound, and the ideal trajectory is displayed on the display device; D． Hydraulic working circuit with pressure compensation The hydraulic working circuit with pressure compensation includes: a turntable valve group and a platform valve group; The turntable valve group includes three circuits of luffing, telescopic and rotary. The main valve of each circuit is equipped with pressure compensation, so that the flow that drives the cylinder or motor is only related to the opening of the main valve, that is, it is approximately linear with the current of the main valve. The proportional relationship has nothing to do with the driving load; at the same time, the three control loops of expansion, amplitude and rotation do not interfere with each other; The platform valve group includes platform swing and platform leveling circuits. The main valve of each circuit has pressure compensation, so that the flow that drives the leveling cylinder or the swing motor is only related to the opening of the main valve, that is, it is similar to the current of the main valve. Linear proportional relationship, independent of the driving load; at the same time, the two control loops of leveling and swing do not interfere with each other; E． Coordinate positioning module The coordinate positioning module detects the current state of the main arm and judges whether to allow intelligent operation; when the intelligent trajectory control is started, the coordinate positioning module receives the long angle sensor signal to determine the boom angle and the length of the boom; receives the turntable encoder signal to determine The rotation angle of the turntable, that is, the rotation angle of the boom relative to the alighting; receive the platform encoder signal to determine the rotation angle of the operating platform relative to the boom; In the XY plane, the position of the end of the boom is calculated by the programmable controller, and compared with the operating range of the equipment, it can be judged whether it can be vertically lifted or horizontally extended; In the area, it is allowed to perform one action of vertical lifting or lowering and one action of horizontal extension or retraction; when the operator pushes the handle to perform an impermissible action, the alarm buzzer warns and the whole machine does not move; In the XZ plane, the programmable controller calculates the rotation angle of the boom relative to the positive direction of getting off the vehicle and the rotation angle of the operating platform relative to the boom, and saves the current status parameters of the boom and the operating platform; The speed priority of the intelligent trajectory operation is lower than the operating speed specified in the working area; the controller receives the detection signal transmitted by the module in real time and compares it with the set program; when the intelligent trajectory operation is close to the envelope of the working area or other limit points, The alarm device prompts the operator; when the intelligent trajectory operation is close to the envelope of the work area or other limit points, the intelligent trajectory operation is restricted, and the alarm device buzzes to alarm; F． Forward Solving Module The forward solving module performs trajectory calculation of the motion path of the operating platform in an ideal state; works after the coordinate positioning module judges that the intelligent trajectory operation can be performed, and receives the boom, turntable and operating platform state parameters and handle operations detected by the coordinate positioning module Signal; When the forward solving module calculates the vertical lifting and horizontal telescopic, the boom angle is the main input reference quantity, and the ideal control signal for controlling the movement of the luffing cylinder and the telescopic cylinder is output respectively; When the forward solving module calculates the horizontal rotation, the rotation angle of the turntable is the main input reference quantity, and the output is the ideal control signal for respectively controlling the movement of the turntable rotary motor, the luffing cylinder, the telescopic cylinder and the swing motor of the operating platform; In the vertical lifting operation, ensure that the projected length of the boom OC on the horizontal X-axis remains constant during the movement, and perform the following calculation: (1)

(2) In the horizontal telescopic operation, ensure that the projected length of the boom OC on the vertical Y axis remains constant during the movement, and perform the following calculation:

(3)

(4) In the horizontal rotation operation, ensure that the projection of the boom OC in the XY plane remains constant during the movement, that is, the projection length along the Y axis and the projected length along the X axis

are kept constant, the following calculations are performed:

(5)

(6) (7)

(8) (9)

(10) Use the sensor to compare the actual length with the calculated length, and the rotation angle with the calculated angle, and import the difference between the two into the loop for calculation, and calculate the control errors of the control loops of variable amplitude, telescopic, turntable rotation, and platform swing as follows:

(11)

(12)

(13)

(14)

(15) In the formula:

is the jib length error,

is the actual length of the boom,

is the length error of the boom telescopic cylinder,

is the ratio of the length change of the boom to the length change of the boom telescopic cylinder,

is the length error of the jib luffing cylinder,

is the actual length of the jib luffing cylinder, is the rotation angle error of the turntable,

is the actual rotation angle of the turntable,

is the platform swing angle error, is the actual swing angle of the platform; G． Deflection Compensation Module The deflection compensation module calculates the fixed deflection deformation of the boom due to its own weight and platform load, and adds the deformation to the control cylinder action signal to correct the trajectory error caused by the deflection deformation; The correction factor is used to correct the deformation caused by the gap between the sliders and the processing quality of the boom in the lap of the boom; in the deflection deformation of the boom, the deflection compensation module calculates the deflection compensation amount of the boom luffing angle under different boom states

; Using the superposition method, the bending deformation and angle compensation value of the boom are obtained as follows:

(16)

(17) H． speed setting module The speed setting module measures the threshold of the horizontal line speed of the outermost edge of the platform at the maximum range of 0.7m/s according to the threshold of the lifting and lowering speed of the working platform of 0.4m/s, and calculates the main input reference quantity of the system—boom amplitude angle signal

: In a vertical lift:

(18) Deriving both sides of formula (18) with respect to time respectively, the following formula is obtained

(19) with initial conditions

,

Solve the differential equation, find the platform 0.4

When lifting at a constant speed, the luffing angle

for:

(20) In horizontal scaling:

(twenty one) Deriving both sides of formula (21) with respect to time respectively, the following formula is obtained

(twenty two) with initial conditions

,

Solve the differential equation and find the platform 0.7

When stretching at a constant speed, the luffing angle

for: (twenty three) In horizontal swivel:

(twenty four) Deriving both sides of formula (24) with respect to time respectively, the following formula is obtained

(25) with initial conditions ,

Solve the differential equation to find 0.7 at the end of the boom

When rotating at a constant speed, the rotation angle

for:

(26) At this time, in order to keep the operating platform in the same direction relative to getting off the vehicle, it should rotate in the opposite direction at a constant speed, and the swing angle

for:

(27) I． Algorithm Optimization Module The algorithm optimization module includes: negative feedback plus feedforward compound correction, PID control link, adding PID control algorithm with dead zone in the telescopic loop; three parts; I1. Composite correction of negative feedback and feedforward: compare the measured values of the luffing cylinder, telescopic cylinder, turntable slewing motor, platform swing motor with the calculated value of the controller respectively, and use formula (11), formula (12), formula (13) , formula (14), formula (15), and add the signal input feedforward channel at the same time to form a combined system of feedforward and feedback control, which greatly reduces the steady-state error and forms a compound correction; I2. PID control link: add PID between the control signal and the main valve, and use its proportional, integral and differential functions; I3. A PID control algorithm with a dead zone is added to the telescopic loop; In vertical lift mode, the boom length changes from shortening to lengthening as the jib traverses the horizontal position; in vertical descent mode, the boom length changes from extended to vertical as the boom traverses the horizontal position. The length becomes shorter; the closer the boom is to the horizontal position, the smaller the change in the length of the boom, and the higher the requirement for position control accuracy; and for the valve-controlled asymmetric cylinder, the rapid change of direction will cause a jump in pressure, causing oil The "inside explosion" or "outside explosion" can not work smoothly when reversing; in order to solve these problems, the PID control method with dead zone is selected; The formula of PID control with dead zone is as follows:

(28) In equation (28), the dead zone It is an adjustable parameter, and the specific value can be determined by field experiments according to the specific equipment; J． Programmable Controllers The programmable controller receives the signal generated by the trajectory control module composed of four parts: coordinate positioning module, forward solving module, deflection compensation module, speed setting module and algorithm optimization module, and uses programming to realize the algorithm of each module in the trajectory control component; When performing vertical lifting or horizontal telescoping, the boom luffing angle is used as the unified input variable, and at the same time, a control current is generated to act on the solenoid valve and alarm device of the luffing and telescopic hydraulic working circuit; When performing horizontal rotation, the rotation angle of the turntable is used as the unified input variable, and at the same time, a control current is generated to act on the solenoid valve and alarm device of the hydraulic working circuit of the luffing, telescopic, turntable rotation and operation platform swing.

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