Mode switching control method of AGV vehicle and AGV vehicle

Abstract

The application discloses a mode switching control method of an AGV vehicle and the AGV vehicle, and the method comprises the following steps: S101, receiving a signal of pressing down a tiller, and switching the vehicle from an AGV mode to an intermediate mode; S102, calculating a current actual steering angle based on a rudder wheel steering voltage value output by a steering potentiometer at present and a voltage angle linear equation; S103, sending a steering adjustment angle to a steering motor based on the current actual steering angle, and controlling the steering motor to adjust based on the adjustment angle; S104, judging whether a difference between the rudder wheel steering voltage value output by the steering potentiometer at present and a tiller steering voltage value is within a preset range, if yes, exiting the intermediate mode and switching to a manual control mode, and if not, returning to the step S102. The application realizes that the tiller can exit the AGV mode and switch to the manual control mode when being pressed down at any position, avoids the steering motor from being in error caused by non-standard user operation, and is more in line with humanization.

Description

Technical Field

[0001] This invention relates to the field of industrial vehicle technology, and in particular to a mode switching control method for AGV vehicles and AGV vehicles. Background Technology

[0002] Most AGVs currently retain two control modes: AGV mode and manual control mode. The existing AGV mode switching method primarily involves sending a command by pressing down on the steering handle to switch between AGV mode and manual control mode. This technology requires the steering handle to be in the neutral position for mode switching to occur. If the steering handle is not in the neutral position and is pressed down, it will cause the steering motor to malfunction.

[0003] As can be seen from the above, existing technology requires the steering wheel to be in the neutral position when switching modes, which has certain limitations. Many field operators are unaware of this requirement and often press the steering wheel down at a certain angle, causing the steering motor to frequently malfunction. Summary of the Invention

[0004] The main objective of this invention is to overcome the aforementioned deficiencies in the prior art and propose a mode switching control method for AGV vehicles and an AGV vehicle in general. This method enables users to exit AGV mode and switch to manual control mode by pressing down the rudder handle at any position, thus avoiding errors in the steering motor caused by improper user operation and making the method more user-friendly.

[0005] The present invention adopts the following technical solution:

[0006] On the one hand, a mode switching control method for AGV vehicles is provided for automatically switching the vehicle from AGV mode to manual control mode; it includes the following steps:

[0007] S101 receives the signal to press down the steering handle and switches the vehicle from AGV mode to intermediate mode;

[0008] S102, calculate the current actual steering angle based on the steering wheel steering voltage value and voltage angle linear equation currently output by the steering potentiometer;

[0009] S103, based on the current actual steering angle, sends the steering adjustment angle to the steering motor, and controls the steering motor to adjust based on the adjustment angle;

[0010] S104. Determine whether the difference between the steering wheel steering voltage value and the steering handle steering voltage value currently output by the steering potentiometer is within the preset range. If yes, exit the intermediate mode and switch to manual control mode; otherwise, return to step S102.

[0011] Preferably, the signal for pressing down the rudder is obtained through a potentiometer at the base of the rudder; specifically, when the rudder is pressed down, the potentiometer is in the open state and outputs a high-level signal; when the rudder is released, the potentiometer is in the closed state and outputs a low-level signal.

[0012] Preferably, the current actual steering angle is calculated based on the steering wheel steering voltage value currently output by the steering potentiometer and the linear equation of the voltage angle, specifically including:

[0013] Obtain the steering wheel steering voltage value currently output by the steering potentiometer;

[0014] The current actual steering angle is calculated using the voltage angle linear equation, as follows:

[0015] y1=kx1+b

[0016] Where x1 represents the steering voltage value of the steering potentiometer currently outputting the steering wheel; y1 represents the current actual steering angle; and k and b are the calibration parameters of the steering motor.

[0017] Preferably, the adjustment angle is a preset fixed angle or a variable angle calculated according to the PID algorithm.

[0018] Preferably, the steering voltage value is obtained through a linear equation relating the steering angle and voltage angle corresponding to the steering position of the steering stick, as follows:

[0019]

[0020] Where x2 represents the steering voltage value of the rudder; y2 represents the steering angle corresponding to the rudder position; and k and b are the calibration parameters of the steering motor.

[0021] Preferably, S104 further includes:

[0022] Determine whether the sum of the steering wheel steering voltage value currently output by the steering potentiometer and the steering wheel verification voltage value currently output by the steering potentiometer is equal to the sum of the rudder steering voltage value and the rudder verification voltage value. If not, return to step S102.

[0023] Preferably, the sum of the steering wheel steering voltage value currently output by the steering potentiometer and the steering wheel verification voltage value currently output by the steering potentiometer is equal to a preset value; the steering wheel verification voltage value currently output by the steering potentiometer is used to verify whether the steering potentiometer output circuit is closed.

[0024] Preferably, the steering voltage value of the rudder is the first input voltage value of the steering potentiometer; the verification voltage value of the rudder is the second input voltage value of the steering potentiometer.

[0025] Preferably, the preset range is greater than or equal to -0.05V and less than or equal to 0.05V.

[0026] On the other hand, an AGV vehicle includes a mode switching control module; the mode switching control module is used to execute the mode switching control method.

[0027] As can be seen from the above description of the present invention, compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) When the present invention receives a signal to press down the steering handle, it first switches the vehicle from AGV mode to an intermediate mode such as AGV_EXIT mode. Then, based on the steering wheel steering voltage value and voltage angle linear equation currently output by the steering potentiometer, it calculates the current actual steering angle and controls the steering motor to adjust based on the current actual steering angle. The steering wheel steering voltage value currently output by the steering potentiometer is compared with the steering handle steering voltage value in real time. When the voltage difference between the two reaches a preset range, it can be determined that the current actual steering angle is equal to the steering angle value corresponding to the steering handle. The steering motor stops adjusting, exits the intermediate mode, and switches to manual control mode. This allows the steering handle to exit AGV mode and switch to manual control mode when pressed down at any position (e.g., when the steering wheel and steering handle are not in the same position). This avoids steering motor errors caused by improper user operation and is more user-friendly.

[0029] (2) In practical applications, the angle of the steering wheel of the AGV vehicle of the present invention cannot be directly obtained. Therefore, it is necessary to calculate the current actual steering angle by directly obtaining the steering voltage value of the steering potentiometer output to achieve steering control. The present invention fits the voltage angle linear equation based on two linear parameters of the steering motor calibration, thereby realizing the conversion of voltage value to steering angle. For the steering handle, the AGV vehicle of the present invention obtains the angle corresponding to the position of the steering handle. Therefore, the steering voltage value of the steering handle is also calculated by the fitted voltage angle linear equation, and finally the AGV mode is switched to manual control mode by comparing the voltage values.

[0030] (3) The present invention is based on the calculation of the current actual steering angle and performs gradual adjustment to prevent voltage sudden change caused by large angle switching and avoid steering motor error;

[0031] (4) When the AGV mode is switched to manual control mode, in addition to judging whether the difference between the steering wheel steering voltage value and the steering handle steering voltage value currently output by the steering potentiometer reaches the preset range, the present invention will also judge whether the sum of the steering wheel steering voltage value and the steering wheel verification voltage value currently output by the steering potentiometer is equal to the sum of the steering handle steering voltage value and the steering handle verification voltage value, thereby verifying whether the main circuit output by the steering potentiometer is closed, and further preventing the steering motor from reporting an error.

[0032] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments, but the mode switching control method for AGV vehicles and the AGV vehicles of the present invention are not limited to the embodiments. Attached Figure Description

[0033] Figure 1 This is a flowchart of the AGV vehicle mode switching control method in this embodiment;

[0034] Figure 2 This is a flowchart illustrating the principle of the AGV vehicle mode switching control method in this embodiment.

[0035] Figure 3 This is a schematic diagram of the steering potentiometer in this embodiment. Detailed Implementation

[0036] The technical solutions in the embodiments of the present invention will be described and discussed in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0037] See Figure 1 As shown, the present invention provides a mode switching control method for AGV vehicles, used to control the vehicle to automatically switch from AGV mode to manual control mode; including the following steps:

[0038] S101 receives the signal to press down the steering handle and switches the vehicle from AGV mode to intermediate mode;

[0039] S102, calculate the current actual steering angle based on the steering wheel steering voltage value and voltage angle linear equation currently output by the steering potentiometer;

[0040] S103, based on the current actual steering angle, sends the steering adjustment angle to the steering motor, and controls the steering motor to adjust based on the adjustment angle;

[0041] S104, determine whether the difference between the steering wheel steering voltage value and the steering handle steering voltage value currently output by the steering potentiometer is within the preset range. If yes, execute S105; otherwise, return to step S102.

[0042] S105, exit intermediate mode and switch to manual control mode.

[0043] The above-mentioned mode switching control method for AGV vehicles can be implemented on the vehicle controller of the AGV vehicle, or it can be implemented through a separate controller. This embodiment does not impose any specific limitations.

[0044] Specifically, the signal to press down the rudder is obtained through a potentiometer at the base of the rudder; specifically, when the rudder is pressed down, the potentiometer is in the open state and outputs a high-level signal; when the rudder is released, the potentiometer is in the closed state and outputs a low-level signal.

[0045] Based on the steering wheel steering voltage value currently output by the steering potentiometer and the linear equation of the voltage angle, the current actual steering angle is calculated, specifically including:

[0046] Obtain the steering wheel steering voltage value currently output by the steering potentiometer;

[0047] The current actual steering angle is calculated using the voltage angle linear equation, as follows:

[0048] y1=kx1+b

[0049] Where x1 represents the steering voltage value of the steering potentiometer currently outputting the steering wheel; y1 represents the current actual steering angle; and k and b are the calibration parameters of the steering motor.

[0050] The adjustment angle is either a preset fixed angle or a variable angle calculated using a PID algorithm. Both the preset fixed angle and the variable angle calculated using the PID algorithm should be smaller than the angle that would cause a voltage surge.

[0051] The steering voltage value of the rudder handle is obtained by a linear equation relating the steering angle and the voltage angle corresponding to the rudder handle position, as follows:

[0052]

[0053] Where x2 represents the steering voltage value of the rudder; y2 represents the steering angle corresponding to the rudder position; and k and b are the calibration parameters of the steering motor.

[0054] S104 further includes:

[0055] Determine whether the sum of the steering wheel steering voltage value currently output by the steering potentiometer and the steering wheel verification voltage value currently output by the steering potentiometer is equal to the sum of the rudder steering voltage value and the rudder verification voltage value. If not, return to step S102.

[0056] The sum of the steering wheel steering voltage value currently output by the steering potentiometer and the steering wheel verification voltage value currently output by the steering potentiometer is equal to a preset value; the steering wheel verification voltage value currently output by the steering potentiometer is used to verify whether the steering potentiometer output circuit is closed.

[0057] The steering voltage value of the rudder is used as the first input voltage value of the steering potentiometer; the verification voltage value of the rudder is used as the second input voltage value of the steering potentiometer.

[0058] For details, see Figure 2The diagram shows the principle of exiting AGV mode by pressing down the rudder handle in any position according to the present invention. The steps include:

[0059] (1) When the AGV vehicle is powered on, it sends linear parameters k and b of steering voltage and steering angle to the vehicle controller. k is the slope corresponding to voltage and angle, and b is the voltage value corresponding to steering angle of 0 degrees (each AGV vehicle will generate corresponding parameters during steering calibration, and the parameters of each vehicle are different).

[0060] (2) The vehicle controller fits a linear equation based on parameters k and b: y = kx + b (x is the voltage value and y is the angle value);

[0061] (3) Set V1, V2, V3 and V4 to record steering voltage values. V1 and V2 record the output voltage values ​​of the steering potentiometer (where V1 is the output steering voltage value of the steering wheel, V2 is the output steering verification voltage value of the steering wheel, V1 controls steering, and V2 verifies whether the main output circuit of the steering potentiometer is closed, such as V1+V2=10V indicating closure). V3 and V4 record the input voltage values ​​of the steering potentiometer, that is, the steering voltage value V3 and the verification voltage value V4 of the steering wheel corresponding to the steering angle 1 at the steering position (V3 is calculated by the linear equation y=kx+b of steering calibration and the angle 1 corresponding to the steering position, and V4 is calculated by V3+V4=10V).

[0062] See Figure 3 As shown, V1 is the voltage output from pin 41, V2 is the voltage output from pin 19, V3 is the voltage input from pin 73, and V4 is the voltage input from pin 74. The steering potentiometer is mounted on the steering wheel (drive wheel).

[0063] (4) Read the switch status of the potentiometer at the root of the rudder, set the parameters, and record the rudder pressing signal and the rudder pressing status.

[0064] (5) In AGV mode, when the rudder is not pressed down, i.e. the rudder pressing down signal is false, the steering motor listens to the steering command sent by the host computer to the vehicle controller and executes the steering command; when the rudder is pressed down, i.e. the rudder pressing down signal is true, the vehicle controller exits AGV mode and the current mode becomes the intermediate mode AGV_EXIT. At this time, the steering motor no longer listens to the steering command sent by the host computer to the vehicle controller.

[0065] (6) The vehicle controller calculates the current actual angle angle2 based on the steering voltage values of V1 and V2 and the linear equation: y = kx + b, and sends a steering adjustment angle value angle3 of 3° every 10 milliseconds relative to angle2 to the steering motor (the steering motor has a limit that it can only rotate 4° in 10 milliseconds, and large-angle switching will cause voltage mutation and the steering motor will report an error). The steering motor executes the angle value angle3 sent by the vehicle controller;

[0066] The steering angle adjustment PID algorithm can use the existing PID algorithm;

[0067] (7) Monitor V1, V2, V3, and V4. If -0.05 < V1 - V3 < 0.05 and V1 + V2 = V3 + V4 (the current actual steering angle is equal to the steering angle value corresponding to the tiller), exit the AGV_EXIT mode and resume to the manual control mode. At this time, the AGV vehicle can be manually controlled.

[0068] The following takes the AGV vehicle as a forklift as an example for illustration.

[0069] ① When the forklift is powered on and executes the AGV automatic handling task, the above steps (1) to (4) are executed at this time;

[0070] ② During the process of the AGV automatically handling goods, press the tiller at any angle (the actual steering angle angle1 corresponding to the tiller position, assuming angle1 is +45 degrees). At this time, step (5) is executed, and the current mode changes from the AGV mode to the AGV_EXIT mode;

[0071] ③ When the previous mode changes to the AGV_EXIT mode, step (6) is executed at this time. The vehicle controller calculates the current actual steering angle value angle2 (assuming angle2 is -25 degrees) based on the steering potentiometer voltage values V1, V2 and the linear equation: y = kx + b, and sends a steering adjustment angle value angle3 of 3° every 10 milliseconds relative to angle2 to the steering motor;

[0072] ④ The steering motor executes the angle value angle3 sent by the vehicle controller. At this time, step (7) is executed, monitoring the steering potentiometer output voltage values V1, V2 and the steering potentiometer input voltage values V3, V4. If -0.05 < V1 - V3 < 0.05 and V1 + V2 = V3 + V4 (the angle value of angle2 changes from -25 degrees to +45 degrees, that is, the current actual steering angle is equal to the steering angle value corresponding to the tiller), exit the AGV_EXIT mode and resume to the manual control mode. At this time, the forklift can be normally manually controlled.

[0073] On the other hand, an AGV vehicle includes a mode switching control module; the mode switching control module is used to execute the mode switching control method.

[0074] The above are merely specific embodiments of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantial modifications made to the present invention using this concept shall be considered as infringing upon the protection scope of the present invention.

Claims

1. A mode switching control method for AGV vehicles, used to control the vehicle to automatically switch from AGV mode to manual control mode; characterized in that, Includes the following steps: S101 receives the signal to press down the steering handle and switches the vehicle from AGV mode to intermediate mode; S102, calculate the current actual steering angle based on the steering wheel steering voltage value and voltage angle linear equation currently output by the steering potentiometer; S103, based on the current actual steering angle, sends the steering adjustment angle to the steering motor, and controls the steering motor to adjust based on the adjustment angle; S104: Determine whether the difference between the steering wheel steering voltage value and the steering handle steering voltage value currently output by the steering potentiometer is within the preset range. If so, exit the intermediate mode and switch to manual control mode. If not, return to step S102; S104 further includes: Determine whether the sum of the steering wheel steering voltage value currently output by the steering potentiometer and the steering wheel verification voltage value currently output by the steering potentiometer is equal to the sum of the rudder steering voltage value and the rudder verification voltage value. If not, return to step S102.

2. The mode switching control method for AGV vehicles according to claim 1, characterized in that, The signal for pressing down the rudder is obtained through a potentiometer at the base of the rudder; specifically, when the rudder is pressed down, the potentiometer is in the open state and outputs a high-level signal; when the rudder is released, the potentiometer is in the closed state and outputs a low-level signal.

3. The mode switching control method for AGV vehicles according to claim 1, characterized in that, Based on the steering wheel steering voltage value currently output by the steering potentiometer and the linear equation of the voltage angle, the current actual steering angle is calculated, specifically including: Obtain the steering wheel steering voltage value currently output by the steering potentiometer; The current actual steering angle is calculated using the voltage angle linear equation, as follows: ； in, This indicates the steering wheel steering voltage value currently output by the steering potentiometer; Indicates the current actual steering angle; and These are the calibration parameters for the steering motor.

4. The mode switching control method for AGV vehicles according to claim 1, characterized in that, The adjustment angle is a preset fixed angle or a variable angle calculated according to the PID algorithm.

5. The mode switching control method for AGV vehicles according to claim 1, characterized in that, The steering voltage value of the rudder handle is obtained by a linear equation relating the steering angle and the voltage angle corresponding to the rudder handle position, as follows: ； in, Indicates the steering voltage value of the rudder; This indicates the steering angle corresponding to the rudder position; and These are the calibration parameters for the steering motor.

6. The mode switching control method for AGV vehicles according to claim 1, characterized in that, The sum of the steering wheel steering voltage value currently output by the steering potentiometer and the steering wheel verification voltage value currently output by the steering potentiometer is equal to a preset value; the steering wheel verification voltage value currently output by the steering potentiometer is used to verify whether the steering potentiometer output circuit is closed.

7. The mode switching control method for AGV vehicles according to claim 1, characterized in that, The steering voltage value of the rudder is the first input voltage value of the steering potentiometer; the verification voltage value of the rudder is the second input voltage value of the steering potentiometer.

8. The mode switching control method for AGV vehicles according to claim 1, characterized in that, The preset range is greater than or equal to -0.05V and less than or equal to 0.05V.

9. An AGV vehicle, characterized in that, It includes a mode switching control module; the mode switching control module is used to perform the method as described in any one of claims 1 to 8.

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