AGV steering wheel stress release control method

Abstract

The invention relates to the field of AGV transportation equipment, in particular to an AGV steering wheel stress release control method which comprises the following steps that S1, a control system detects the speed of all power units to confirm that a vehicle is still; s2, detecting the current of all power units when the time for keeping the vehicle static is greater than T; and S3, setting a current threshold value A, and when the current detection value of a certain power unit is greater than or equal to the current threshold value, performing release enabling operation on the corresponding power unit. During stress release, intervention of a band-type brake system is not needed, control is simple, meanwhile, compared with a traditional stress release mode, the service life of the band-type brake system is prolonged, and the use cost of the AGV is reduced; the stress release only aims at the unit with the power exceeding the threshold value, the locking force still exists for the non-operated power unit and the steering wheel, the AGV can still keep stable and static, and therefore high safety and reliability are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of AGV transportation equipment, and in particular to a stress release control method for an AGV steering wheel. Background Art

[0002] AGV vehicles are commonly used logistics and transportation equipment in modern manufacturing enterprises. They are indispensable transportation equipment in the field of production and manufacturing. Various manufacturing industries, from air conditioners and televisions to automobiles, use AGV transport vehicles as the core to organize material transportation within the factory. AGV transport vehicles usually use servo motors as power units. When the servo motor is stationary, due to the consistency of the movements between multiple wheel sets and the flatness of the ground on which the AGV walks, each servo motor has a large internal stress when stationary. In order to resist such stress, the motor needs to provide a large torque to maintain a similar dynamic balance. This leads to a phenomenon: although the AGV vehicle is parked in place and not moving, the system is always consuming a large amount of electricity. The electricity it consumes even exceeds the energy consumption of the vehicle when it is moving. This brings great trouble to AGV, a transportation device that uses batteries to provide energy.

[0003] To address this problem, the solution usually adopted is to lock the wheelset with the steering wheel brake when the vehicle stops, and turn off the servo motor enable at the same time. Although this solution solves the problem of steering wheel stress, its frequent operation of the brake greatly reduces the service life of the brake, which is particularly prominent in systems with frequent start-stop.

[0004] Therefore, how to avoid frequent braking without the help of the brake system and reduce the service life of the brake system, while effectively and safely releasing the stress between the AGV steering wheels to reduce the energy consumption when the vehicle is stationary is a problem that technical personnel in this field need to consider. Summary of the invention

[0005] The purpose of the present invention is to provide a method for controlling the stress release of an AGV steering wheel, so as to solve the problem of internal stress accumulation between the steering wheels when the AGV vehicle is stationary in the prior art.

[0006] The technical solution of the present invention is: a method for controlling stress release of an AGV steering wheel, comprising the following steps:

[0007] S1. The control system detects the speed of all power units to confirm that the speed of all power units is zero, that is, the vehicle is stationary;

[0008] S2. When the time for the timing vehicle to remain stationary is greater than T, the current of all power units is detected;

[0009] S3. Set a current threshold A. When the current detection value of the power unit is greater than the current threshold, release enabling operations are performed on the corresponding power units one by one.

[0010] Preferably, in step S2, when the speed of the power unit is greater than zero, the timing is stopped, and it is confirmed again whether the speeds of all the power units are zero, and the timing is restarted.

[0011] Preferably, in steps S2 and S3, the current detection of the power units is performed one by one. When the current is less than a threshold, the next power unit is detected. When the current is greater than the threshold, the release enabling operation is performed first, and then the next power unit is detected.

[0012] Preferably, the operation of releasing the enable is to sequentially disable and re-enable.

[0013] Preferably, in step S3, when the speed of the power unit is greater than zero, the release enabling operation is interrupted, and the operation of S1 is continued.

[0014] Compared with the prior art, the advantages of the present invention are:

[0015] (1) Stress release does not require the intervention of the brake system, which makes the control simple. Compared with the traditional stress release method, it increases the service life of the brake system and reduces the use cost of AGV.

[0016] (2) The stress release is performed on the power units that exceed the current threshold one by one, so the power units and steering wheels that are not operated still have locking force, and the AGV vehicle can still remain stable and stationary, thus having higher safety and reliability;

[0017] (3) Since stress is released one by one, the impact of a single stress release is small, thus improving the stability of the AGV body;

[0018] (4) The stress between the vehicle power units is the "internal stress" between the wheel sets, so under normal circumstances, it is not necessary to operate all the power units. When the stress of some power units is released, the stress of the remaining power units is also released accordingly, and the stress release action is efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0020] Figure 1 It is a schematic diagram of the AGV steering wheel stress release control method of the present invention;

[0021] Figure 2 This is a flow chart of the AGV steering wheel stress release control method described in the present invention. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with specific embodiments:

[0023] like Figure 1-2 As shown, the present invention is applied to the stress release of the power unit of an AGV vehicle having four or more power units when the vehicle is parked. Only with four or more power units can it be ensured that the loss of braking force when releasing the stress will not affect the reliability of the locking when the vehicle is stationary. Specifically, a method for controlling the stress release of an AGV steering wheel includes the following steps:

[0024] First, the control system detects the speed of all power units to confirm that the speed of all power units is zero and the vehicle is stationary. AGV vehicles generally have several power units, including servo controllers, servo motors, steering wheels and other components. The servo controller can detect the motor speed and motor current to confirm whether the vehicle is in a stationary state. It should be noted that the vehicle is only confirmed to be stationary when the speed of all power units is zero. In addition, during the execution of the entire stress release, the speed detection of the power unit is carried out continuously. When the speed of the vehicle is greater than zero, the stress release action stops. When the vehicle is stationary again, the subsequent timing action is executed.

[0025] When the vehicle is stationary, it does not immediately enter the stress release process, but when the stationary state is maintained for a time greater than T, the current of all power units is detected. A current threshold A is set. When the current detection value of the power unit is greater than the current threshold, the release enable operation is performed on the corresponding power unit. In this embodiment, the current detection is performed on all power units in sequence. When the current is less than the threshold, the next power unit is detected; when the real-time current of the corresponding power unit is greater than the threshold A, the disconnection and re-enabling operations are performed in sequence to complete the stress release of the corresponding power unit, and then the next power unit is detected. It should be noted that in the process of detecting the current of the power units one by one, if the vehicle starts to move and the speed is greater than zero, the current detection stops and returns to the previous real-time detection of the vehicle speed. In addition, in the actual operation process, when the stress release of some power units is completed, the stress of other power units is released accordingly, so it is actually not necessary to perform stress release actions on all power units.

[0026] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the scope of protection of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is limited by the attached claims rather than the above description, and it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the present invention.

Claims

1. A method for controlling stress release of an AGV steering wheel, characterized in that: The following steps are involved: S1. The control system detects the speed of all power units to confirm that the speed of all power units is zero, that is, the vehicle is stationary; S2. When the time for the timing vehicle to remain stationary is greater than T, the current of all power units is detected; S3. Set a current threshold A. When the current detection value of the power unit is greater than the current threshold, perform a release enabling operation on the corresponding power unit.

2. The AGV steering wheel stress release control method according to claim 1, characterized in that: In step S2, when the speed of the power unit is greater than zero, the timing is stopped, and it is confirmed again whether the speeds of all the power units are zero, and the timing is restarted.

3. The AGV steering wheel stress release control method according to claim 1, characterized in that: In the steps S2 and S3, the current of the power unit is detected, and the potential energy release operation is performed one by one on the power units whose current is greater than a threshold.

4. The AGV steering wheel stress release control method according to claim 1, characterized in that: The operation of releasing the enable is to sequentially perform disabling and re-enabling.

5. The AGV steering wheel stress release control method according to claim 1, characterized in that: In step S3, when the speed of the power unit is greater than zero, the release enabling operation is interrupted, and the operation of S1 is continued.

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