Laser positioning device for RGV (Rail Guided Vehicle)

Abstract

The utility model provides an RGV trolley laser positioning device which comprises a control device arranged on a trolley body and positioning markers arranged at all stations. The control device comprises a main controller, a servo driver, a servo motor and a laser sensor, and the main controller is in communication connection with the servo driver; the servo motor is used for driving the driving wheel to rotate to drive the vehicle body to move on the track; the laser sensor is connected with the main controller, and the laser sensor is used for detecting the positioning marker; in the utility model, the main controller divides the distance between the current station and the target station into two stages, the first stage is that the servo motor operates in a position mode, the second stage is that the servo motor operates in a speed mode at a low speed, the laser sensor stops when sensing the positioning marker of the target station, and the first stage operates at a full speed. The second-stage operation distance is extremely short, low-speed operation does not affect the overall efficiency, meanwhile, the positioning precision is improved, and the project cost and the maintenance cost are reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of RGV cars, and particularly relates to an RGV car laser positioning device. Background Art

[0002] RGV (Rail Guided Vehicle), a rail-guided vehicle, refers to a car running on a specific track, which can run automatically without manual operation and has a fast running speed.

[0003] In the past, there were usually two ways to position heavy-load RGVs.

[0004] First, a laser rangefinder or a coding scale is used as the positioning reference, and it runs in sections. When approaching the target point, it decelerates in advance and runs at a low speed until it stops at the target point. This design scheme defaults that the laser rangefinder or the coding scale is the absolute position. However, in fact, both the laser rangefinder and the coding scale have measurement errors and error risks, which will lead to insufficient accuracy or even positioning errors, and the project cost and maintenance cost are relatively high.

[0005] Second, the built-in encoder of the servo motor is used as the positioning reference, and it also runs in two stages. In the first stage, it is in the speed mode. After reaching a certain distance from the target point, it switches to the position mode and runs at a low speed until it stops at the target point. There is still a risk of track slippage when running in the position mode in the second stage of this method. However, the scheme design defaults to ignoring the track slippage when running at a low speed, and there are still problems of insufficient positioning accuracy or even positioning errors. This scheme has a lower cost, but has a larger positioning accuracy error and a positioning error risk.

[0006] Therefore, it is necessary to design an RGV car laser positioning device that improves the positioning accuracy and ensures the operation efficiency to solve the current technical problems. Summary of the Invention

[0007] In view of the deficiencies in the prior art, the utility model provides an RGV car laser positioning device that improves the positioning accuracy and ensures the operation efficiency.

[0008] The technical solution of the utility model is as follows: an RGV car laser positioning device, including: a control device arranged on the vehicle body and positioning markers arranged at each work station; the control device includes a main controller, a servo driver, a servo motor and a laser sensor, and the main controller is communicatively connected with the servo driver; the servo motor is used to drive the driving wheel to rotate so as to drive the vehicle body to move on the track; the laser sensor is connected with the main controller, and the laser sensor is used to detect the positioning marker.

[0009] The main controller is in communication connection with the servo driver via a communication module. The main controller sends motion control instructions to the servo driver via the communication module. The servo driver reports positioning information to the main controller via the communication module.

[0010] The communication module is a CANopen communication module.

[0011] The vehicle body has four driving wheels, and the four driving wheels are driven to rotate by four servo motors respectively. The four servo motors are respectively connected to four servo drivers, and the four servo drivers are all communicatively connected to the main controller through the communication module.

[0012] The width of the positioning marker is 3 mm.

[0013] The laser sensor is a single-point laser sensor, and the spot diameter of the single-point laser sensor is 1.5 mm.

[0014] The main controller is Siemens 1214PLC.

[0015] Beneficial effects of the utility model:

[0016] (1) In the present invention, the encoder provided by the servo motor is used as a rough position reference, and the positioning marker installed at the target station is used as the absolute position standard. The positioning marker is fixedly installed at the target station to avoid positioning standard errors.

[0017] (2) The main controller divides the distance between the current workstation and the target workstation into two stages. In the first stage, the adverse effects of track slippage are placed. The servo motor operates in position mode, allowing track slippage to cause errors in the distance of the first stage. In the second stage, the servo motor operates in speed mode at low speed. The laser sensor stops when it senses the positioning marker of the target workstation. The first stage runs at full speed, and the second stage runs a very short distance. Low-speed operation will not affect the overall efficiency. At the same time, it improves positioning accuracy and reduces project and maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a principle block diagram of the control device in the medium and heavy-load RGV precise positioning control system of this utility model.

[0019] Figure 2 This is the positioning principle diagram of the medium and heavy-load RGV precise positioning control system of this utility model. DETAILED DESCRIPTION

[0020] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and does not constitute any limitation on the present invention and its application or use. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the present invention thorough and complete and to fully convey the scope of the present invention to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the components and steps, the composition of the materials, the numerical expressions and the numerical values set forth in these embodiments should be interpreted as being merely exemplary and not as limiting.

[0021] The terms "first," "second," and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are simply used to distinguish different parts. Terms such as "include" or "comprising" mean that the elements preceding the term include the elements listed after the term, and do not exclude the possibility of also including other elements. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0022] like Figure 1 and 2 As shown, the RGV trolley laser positioning device includes: a control device arranged on the vehicle body and a positioning marker 6 arranged at each workstation; the control device includes a main controller 1, a servo driver 3, a servo motor 4 and a laser sensor 5, and the main controller 1 is communicatively connected to the servo driver 3; the servo motor 4 is used to drive the driving wheel to rotate to drive the vehicle body to move on the track; the laser sensor 5 is connected to the main controller 1, and the laser sensor 5 is used to detect the positioning marker 6; in this embodiment, the encoder provided by the servo motor is used as a rough position reference, and the positioning marker 6 installed at the target workstation is used as an absolute reference. For the position standard, the positioning marker 6 is fixedly installed at the target workstation to avoid positioning standard errors; the main controller 1 divides the distance between the current workstation and the target workstation into two stages. The adverse effect of track slippage is placed in the first stage. The servo motor operates in position mode, allowing track slippage to cause errors in the distance of the first stage. In the second stage, the servo motor adopts speed mode and runs at low speed. The laser sensor stops when it senses the positioning marker 6 of the target workstation. The first stage runs at full speed, and the second stage runs a very short distance. Low-speed operation will not affect the overall efficiency. At the same time, it improves positioning accuracy and reduces project cost and maintenance cost.

[0023] In the above embodiments, the control method of the main controller 1 includes: dividing the total mileage between the current station and the target station into a first-stage position mode mileage and a second-stage position mode mileage; in the first-stage position mode mileage, the main controller 1 controls the servo motor 4 to drive the vehicle body to run along the track at the maximum system-designed speed in the position mode, and in the second-stage position mode mileage, the main controller 1 controls the servo motor 4 to drive the vehicle body to run along the track at a speed lower than the maximum system-designed speed in the speed control mode; in the second-stage position mode mileage, when the laser sensor 5 detects the positioning marker 6, it sends a signal to the main controller 1, and the main controller 1 stops the operation of the servo motor 4; to ensure the high-efficiency operation and high positioning accuracy of the heavy-load RGV, the operation of the heavy-load RGV is divided into a first stage and a second stage. The total mileage between the current station and the target station can be divided into a first-stage position mode mileage and a second-stage speed mode mileage. In the first stage, the main controller 1 controls the servo motor 4 to run at the maximum system-designed speed in the position mode, and its operation efficiency will not be reduced. When the heavy-load RGV reaches the end of the first-stage position mode mileage calculated in the main controller 1, it enters the second stage. In the second stage, the servo motor runs in the speed mode with a lower speed. When the heavy-load RGV reaches the target station, the laser sensor 5 scans the positioning marker 6 to generate a signal indicating arrival and sends it to the main controller 1. The main controller 1 immediately sends a stop instruction, and the servo motor 4 stops running, and the heavy-load RGV stops running, improving the positioning accuracy; where the second-stage speed mode mileage is a fixed value, and the first-stage position mode mileage is obtained by subtracting the second-stage speed mode mileage from the total mileage; the main controller 1 obtains the distance between the current station and the target station to get the total mileage, and subtracts the fixed second-stage speed mode mileage from the total mileage to obtain the first-stage position mode mileage. The heavy-load RGV immediately enters the speed mode operation of the second stage when it reaches the end of the first-stage position mode mileage; more specifically, the first-stage position mode mileage is 20 mm, and in the second-stage speed mode mileage, the main controller controls the servo motor to drive the vehicle body to run along the track at 0.8 m / min.

[0024] In some embodiments, as a specific implementation manner of the communication connection between the main controller 1 and the servo driver 3, the main controller 1 is communicatively connected to the servo driver 3 through a communication module. The main controller 1 sends a motion control instruction to the servo driver 3 through the communication module 2, and the servo driver 3 reports positioning information to the main controller 1 through the communication module 2.

[0025] In the above embodiments, as a specific implementation manner of the communication module 2, the communication module 2 is a CANopen communication module.

[0026] In some embodiments, the vehicle body has four drive wheels, and the four drive wheels are respectively driven to rotate by four servo motors 4. The four servo motors 4 are respectively connected with four servo drivers 3, and the four servo drivers 3 are all communicatively connected with the main controller 1 through the communication module 2.

[0027] In some embodiments, the width of the positioning marker 6 is 3 mm.

[0028] In some embodiments, the laser sensor 5 is a single-point laser sensor. The spot diameter of the single-point laser sensor is 1.5 mm, the effective area is half of the spot area, and the light beam does not spread, which does not affect the positioning accuracy. The width of the positioning marker 6 is 3 mm.

[0029] In some embodiments, the main controller 1 is a Siemens 1214 PLC.

[0030] So far, the embodiments of the present invention have been described in detail. In order to avoid obscuring the concept of the present invention, some details well known in the art are not described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

[0031] The above-described embodiments only represent some embodiments of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the utility model patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the utility model patent shall be subject to the appended claims.

Claims

1. An RGV car laser positioning device, characterized in that Including: A control device provided on the vehicle body and positioning markers provided at each work station; The control device includes a main controller, a servo driver, a servo motor, and a laser sensor, and the main controller is communicatively connected to the servo driver; The servo motor is used to drive the driving wheels to rotate to drive the vehicle body to move on the track; The laser sensor is connected to the main controller, and the laser sensor is used to detect the positioning marker.

2. The RGV vehicle laser positioning device according to claim 1, characterized in that: The main controller is communicatively connected to the servo driver through a communication module. The main controller sends a motion control instruction to the servo driver through the communication module, and the servo driver reports positioning information to the main controller through the communication module.

3. The RGV vehicle laser positioning device according to claim 2, characterized in that: The communication module is a CANopen communication module.

4. The RGV cart laser positioning device according to claim 2, characterized in that: The vehicle body has four driving wheels, and the four driving wheels are respectively driven to rotate by four servo motors. The four servo motors are respectively connected to four servo drivers, and the four servo drivers are all communicatively connected to the main controller through the communication module.

5. The RGV cart laser positioning device according to claim 1, characterized in that: The width of the positioning marker is 3 mm.

6. The RGV cart laser positioning device according to claim 1, characterized in that: The laser sensor is a single-point laser sensor, and the spot diameter of the single-point laser sensor is 1.5 mm.

7. The RGV vehicle laser positioning device according to claim 1, characterized in that: The main controller is a Siemens 1214 PLC.

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