A high-precision positioning control method for a four-way vehicle

Abstract

The present application belongs to the technical field of positioning control of four-way vehicles, and discloses a high-precision positioning control method for a four-way vehicle, comprising the following steps: S1. An empty-load calibration stage; S2. A real-time operation stage; S3. Judging whether the vehicle is stopped or not, if yes, returning to step S1, if not, executing step S4; S4. Using the gravity compensation model in step S1.3 to correct the acceleration in step S2.2 to obtain real motion parameters. The present application can improve positioning accuracy, has a dynamic adjustment mechanism, and can adapt to complex environments. That is, by establishing a gravity compensation model, the present application eliminates the projection interference of gravity on the X / Y axis acceleration, so that the four-way vehicle can adapt to complex and variable logistics environments, expand the application range of the four-way vehicle, and improve efficiency, solving the problem that the prior art is difficult to adapt to complex and variable logistics environments.

Description

Technical Field

[0001] This invention belongs to the field of four-way vehicle positioning and control technology, specifically relating to a high-precision positioning and control method for four-way vehicles. Background Technology

[0002] In automated logistics systems, four-way vehicles, as flexible handling equipment, rely heavily on precise positioning control to improve logistics efficiency and reduce cargo damage. As the level of logistics automation increases, the requirements for the positioning accuracy of four-way vehicles also rise. However, the positioning accuracy of four-way vehicles under different load conditions is affected by wheel-rail contact deformation and changes in friction, leading to positioning deviations.

[0003] Currently, the positioning control of four-way vehicles mainly relies on the feedback signal from the motor encoder, which can provide relatively accurate positioning information under no-load conditions. However, when the load of the four-way vehicle increases, due to changes in wheel-rail contact deformation and friction, the feedback signal from the motor encoder alone cannot accurately reflect the actual displacement, leading to a decrease in positioning accuracy. In other words, the motor encoder feedback signal cannot directly reflect the impact of load changes on wheel-rail contact deformation and friction, resulting in inconsistent positioning accuracy under different load conditions. Furthermore, existing methods lack a dynamic adjustment mechanism for four-way vehicles under different load conditions, making high-precision positioning control impossible. Therefore, developing a high-precision positioning control method for four-way vehicles that can adapt to different load conditions is of great significance for improving the level of logistics automation. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a high-precision positioning control method for four-way vehicles, aiming to solve the technical problem of inconsistent positioning accuracy of four-way vehicles under different load conditions; existing methods lack a dynamic adjustment mechanism for four-way vehicles under different load conditions, thus failing to achieve high-precision positioning control.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A high-precision positioning control method for a four-way vehicle includes the following steps: S1. No-load calibration stage: S1.1 Install the IMU at the center of gravity of the four-way vehicle, ensuring that the X / Y axes of the IMU are strictly aligned with the direction of movement of the four-way vehicle; S1.2 Under no-load conditions, the four-way vehicle moves along the X / Y axis with constant acceleration. The inertial acceleration measured by the IMU and the acceleration set by the motor encoder in position mode are recorded. The reference acceleration ratio is calculated by the ratio of the inertial acceleration to the acceleration set by the motor encoder in position mode. S1.3 A gravity compensation model is established using the principle of IMU gyroscope to calculate the pitch angle θ and roll angle φ when the four-way vehicle is running, eliminate the projection interference of gravity on the X / Y axis acceleration, and obtain the true acceleration; S2. Real-time operation phase; S2.1 Following step S1.2, the combined inertial acceleration of the X / Y axes measured by the IMU during the real-time operation of the four-way vehicle is collected in real time. This includes the real-time inertial acceleration and the acceleration set by the motor encoder in position mode, as well as the real-time motor encoder acceleration. The real-time acceleration ratio is calculated based on the ratio of the real-time inertial acceleration to the real-time motor encoder acceleration. S2.2 Correct the four-way vehicle displacement based on the deviation between the real-time acceleration ratio and the reference acceleration ratio in step S2.1; obtain the target displacement; S3. Determine if the vehicle has stopped running. If yes, return to step S1; otherwise, proceed to step S4. S4. Use the gravity compensation model in step S1.3 to correct the acceleration in step S2.2 to obtain the true motion parameters.

[0006] Preferably, in step S1.1, the deviation between the X / Y axis of the IMU and the four-way vehicle movement direction is no more than ±0.5°. Preferably, in step S1.2, the predetermined time is 10-15 minutes.

[0007] Preferably, in step S1.3, when the four-way vehicle is in an unloaded operating state, the inertial acceleration measured by its IMU is a_IMU. 空载 The acceleration of the motor encoder in position mode is set to a_motor 空载 Therefore, the reference acceleration ratio satisfies: k0 = |a_IMU 空载 | / |a_motor 空载 |

[0008] Preferably, in step S2.1, when the four-way vehicle is in real-time operation, the inertial acceleration measured by its IMU is a_IMU. 实时 The acceleration of the motor encoder in position mode is set to a_motor 实时 Thus, the real-time acceleration ratio satisfies: k = |a_IMU 实时 | / |a_motor 实时 | .

[0009] Preferably, in step S2.2, the target displacement correction method is as follows: S_corrected = S_motor × (1+ ) Where: S_corrected is the adjusted displacement, S_motor is the target displacement fed back by the motor encoder, k is the real-time acceleration ratio, and k0 is the reference acceleration ratio; the corrected target displacement is sent to the motor encoder controller to achieve high-precision positioning control.

[0010] Preferably, the gravity compensation model satisfies: a_inertial_x = a_meas_x - g•sin(θ); a_inertial_y = a_meas_y - g•sin(φ); Calculate the X / Y axis accelerations after gravity compensation; where x is the principal track and y is the principal track; g is the gravitational acceleration, taken as 9.81 m / s², θ is the pitch angle, and φ is the roll angle.

[0011] A computing device includes a processor and a memory for storing a processor-executable program, wherein when the processor executes the program stored in the memory, it implements the steps of the method described above. A storage medium stores a program / instructions that, when executed by a processor, implement the steps of the method described above. A computer program product includes a computer program / instructions, characterized in that, when executed by a processor, the computer program / instructions implement the steps of the method described above.

[0012] Compared with the prior art, the beneficial effects of the present invention are: 1. Improved positioning accuracy: By calibrating the acceleration data ratio between the IMU and the motor encoder under no-load conditions and combining it with real-time measurement values ​​to dynamically correct the target displacement, high-precision horizontal X / Y axis positioning control under different load conditions can be achieved, solving the problem of inconsistent positioning accuracy of four-way vehicles under different load conditions.

[0013] 2. Dynamic adjustment mechanism: This solution can adjust the displacement according to the deviation between the real-time acceleration ratio and the reference value, thereby achieving high-precision positioning control and solving the problem that existing methods lack a dynamic adjustment mechanism for four-way vehicles under different load conditions.

[0014] 3. Adaptability to complex environments: This solution establishes a gravity compensation model to eliminate the projection interference of gravity on the X / Y axis acceleration, enabling the four-way vehicle to adapt to complex and ever-changing logistics environments. This expands the application scope of the four-way vehicle and improves efficiency, solving the problem that existing technical solutions are difficult to adapt to complex and ever-changing logistics environments. Attached Figure Description

[0015] Figure 1 This is the control flowchart of the present invention patent. Detailed Implementation To make the technical means, creative features, objectives and effects of this invention easier to understand, the following embodiments are described in detail with reference to the accompanying drawings. It should be noted that the description of these embodiments is for the purpose of helping to understand this invention, but does not constitute a limitation of this invention.

[0016] like Figure 1 As shown, the high-precision positioning control method for a four-way vehicle includes the following steps: S1. No-load calibration stage: S1.1 Install the IMU at the center of gravity of the four-way vehicle, and use a laser level and angle measuring instrument to perform installation calibration to ensure that the deviation between the X / Y axis of the IMU and the direction of movement of the four-way vehicle does not exceed 0.5 degrees; preferably, the X / Y axis of the IMU is strictly aligned with the direction of movement of the four-way vehicle. S1.2 Under no-load conditions, the four-way vehicle moves along the X / Y axes with constant acceleration. Using a data acquisition system, the inertial acceleration a_IMU measured by the IMU is recorded at an acquisition frequency of 100Hz. 空载 The acceleration a_motor set by the motor encoder in position mode 空载 The reference acceleration ratio is calculated by comparing the inertial acceleration with the acceleration set by the motor encoder in position mode, i.e., k0 = |a_IMU 空载 | / |a_motor 空载 |; S1.3 A gravity compensation model is established using the IMU gyroscope principle to calculate the pitch angle θ and roll angle φ during the operation of the four-way vehicle, eliminating the projection interference of gravity on the X / Y axis acceleration and obtaining the true acceleration: The gravity compensation model satisfies: a_inertial_x = a_meas_x - g•sin(θ); a_inertial_y = a_meas_y - g•sin(φ); Calculate the X / Y axis accelerations after gravity compensation; where x is the principal track and y is the principal track; g is the gravitational acceleration, taken as 9.81 m / s², θ is the pitch angle, and φ is the roll angle; S2. Real-time operation phase; S2.1 Following step S1.2, the combined inertial acceleration along the X / Y axes measured by the IMU during the real-time operation of the four-way vehicle is acquired in real time, i.e., the real-time inertial acceleration a_IMU. 实时 The acceleration set by the motor encoder in position mode, i.e., the real-time motor encoder acceleration a_motor 实时 The real-time acceleration ratio k = |a_IMU is calculated using the ratio of real-time inertial acceleration to real-time motor encoder acceleration.实时 | / |a_motor 实时 |; S2.2 Correct the four-way vehicle displacement based on the deviation between the real-time acceleration ratio and the reference acceleration ratio from step S2.1; thus obtaining the target displacement, i.e. S_corrected = S_motor × (1+ ) Where: S_corrected is the adjusted displacement, S_motor is the target displacement fed back by the motor encoder, and k is the real-time acceleration ratio. The base acceleration ratio is used; the corrected target displacement is sent to the motor encoder controller to achieve high-precision positioning control. S3. Determine if the vehicle has stopped running. If yes, return to step S1; otherwise, proceed to step S4. S4. Use the gravity compensation model in step S1.3 to correct the acceleration in step S2.2 to obtain the true motion parameters.

[0017] Before step S1.2, when the four-way vehicle is stationary, the IMU accelerometer output is recorded for 10 minutes at a sampling frequency of 1Hz using a data acquisition system. The average value of all accelerations in the accelerometer is calculated within 10 minutes, and this average value is used as the zero bias compensation value b. a After obtaining the zero-bias compensation value, this value is stored in the IMU for subsequent acceleration measurements, i.e., in step S1.2, a_IMU 空载 =a_IMU 空载 -b a .

[0018] A computing device includes a processor and a memory for storing a processor-executable program, wherein when the processor executes the program stored in the memory, it performs the steps of the method described above.

[0019] A storage medium storing a program / instructions that, when executed by a processor, implement the steps of the method described above.

[0020] A computer program product includes a computer program / instructions that, when executed by a processor, implement the steps of the method described above.

[0021] This invention can effectively improve the positioning accuracy of four-way vehicles, meeting the needs of automated logistics and intelligent warehousing; at the same time, it can improve the control accuracy of equipment, promoting the development of precision manufacturing; in addition, it can improve the operating efficiency and accuracy of logistics four-way vehicles; and it has wide applications in fields such as automated logistics, intelligent warehousing, and precision manufacturing.

[0022] The above embodiments are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Various modifications or variations that can be made by those skilled in the art without creative effort within the scope of the appended claims are still within the scope of protection of this patent.

Claims

1. A high-precision positioning control method for a four-way vehicle, characterized in that, Includes the following steps: S1. No-load calibration stage: S1.1 Install the IMU at the center of gravity of the four-way vehicle, ensuring that the X / Y axes of the IMU are strictly aligned with the direction of movement of the four-way vehicle; S1.2 Under no-load conditions, the four-way vehicle moves along the X / Y axis with constant acceleration. The inertial acceleration measured by the IMU and the acceleration set by the motor encoder in position mode are recorded. The reference acceleration ratio is calculated by the ratio of the inertial acceleration to the acceleration set by the motor encoder in position mode. S1.3 A gravity compensation model is established using the principle of IMU gyroscope to calculate the pitch angle θ and roll angle φ when the four-way vehicle is running, eliminate the projection interference of gravity on the X / Y axis acceleration, and obtain the true acceleration; S2. Real-time operation phase; S2.1 Following step S1.2, the combined inertial acceleration of the X / Y axes measured by the IMU during the real-time operation of the four-way vehicle is collected in real time. This includes the real-time inertial acceleration and the acceleration set by the motor encoder in position mode, as well as the real-time motor encoder acceleration. The real-time acceleration ratio is calculated based on the ratio of the real-time inertial acceleration to the real-time motor encoder acceleration. S2.2 Correct the four-way vehicle displacement based on the deviation between the real-time acceleration ratio and the reference acceleration ratio in step S2.1; Obtain the target displacement; S3. Determine if the vehicle has stopped running. If yes, return to step S1; otherwise, proceed to step S4. S4. Use the gravity compensation model from step S1.3 to correct the acceleration in step S2.2 to obtain the true motion parameters.

2. The control method according to claim 1, characterized in that, In step S1.3, when the four-way vehicle is in an unloaded operating state, the inertial acceleration measured by its IMU is a_IMU. 空载 The acceleration of the motor encoder in position mode is set to a_motor 空载 Therefore, the reference acceleration ratio satisfies: k0= |a_IMU 空载 | / |a_motor 空载 |。 3. The control method according to claim 1, characterized in that, In step S2.1, when the four-way vehicle is in real-time operation, the inertial acceleration measured by its IMU is a_IMU. 实时 The acceleration of the motor encoder in position mode is set to a_motor 实时 Thus, the real-time acceleration ratio satisfies: k = |a_IMU 实时 | / |a_motor 实时 | 4. The control method according to claim 1, characterized in that, In step S2.2, the target displacement correction method is as follows: ； S_corrected = S_motor × (1+ ); Where: S_corrected is the adjusted displacement, S_motor is the target displacement fed back by the motor encoder, k is the real-time acceleration ratio, and k0 is the reference acceleration ratio.

5. The control method according to claim 4, characterized in that, The gravity compensation model satisfies: a_inertial_x = a_meas_x - g•sin(θ); a_inertial_y = a_meas_y - g•sin(φ); Calculate the X / Y axis accelerations after gravity compensation; where x is the principal trajectory, y is the principal trajectory, g is the gravitational acceleration, taken as 9.81 m / s², θ is the pitch angle, and φ is the roll angle.

6. A computing device, characterized in that, It includes a processor and a memory for storing a processor-executable program, wherein when the processor executes the program stored in the memory, it implements the steps of the method as described in any one of claims 1 to 5.

7. A storage medium storing a program / instructions, characterized in that, When the program / instructions are executed by the processor, they implement the steps of the method as described in any one of claims 1 to 5.

8. A computer program product, comprising a computer program / instructions, characterized in that... When the computer program / instruction is executed by the processor, it implements the steps of the method according to any one of claims 1-5.

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