GEO positioning system with external encoder

Abstract

The invention provides a GEO positioning system with an external encoder. The GEO positioning system comprises a moving unit, an encoding ruler, a motor, a transmission structure, the external encoder and a control unit, the coded ruler is installed on the moving unit, and the external encoder is installed on a conveying station and can read the coded ruler installed on the moving unit to obtain actual position information of the coded ruler and transmit the actual position information to the control unit; the motor is used for providing power to drive the transmission structure to operate; an encoder is arranged in the motor and is used for monitoring the rotating speed and the rotating angle of a main shaft of the motor and transmitting data to the control unit for positioning judgment; the transmission structure is used for transmitting rotation power of the motor to the moving unit; the control unit controls the movement of the moving unit according to a preset control rule. According to the invention, real-time positioning monitoring of the mobile unit can be realized, and positioning deviation caused by transmission pair faults in the prior art is eliminated.

Description

Technical Field

[0001] The present invention relates to the field of automobiles, and in particular to a GEO positioning system with an external encoder. Background Art

[0002] The traditional Pallet trolley conveyor line station positioning uses a horizontal servo motor with a built-in encoder for PLC programming control. The principle is to detect the encoder value of the motor spindle. When the PLC program determines that the encoder value enters the deceleration trigger range, the motor is instructed to decelerate; when the encoder value reaches the stop trigger range, the motor brake stops, thereby enabling the Pallet to achieve GEO positioning on the conveyor line.

[0003] However, this positioning method has a major flaw. Since there are multiple transmission pairs between the motor spindle and the final drive roller, if there is an abnormality in the transmission pair, the existing positioning method only relies on the encoder feedback of the motor spindle and cannot detect whether the Pallet has actually reached the set position. This may lead to positioning deviation, which may affect the accuracy of welding and other processes, or may cause major safety accidents such as collisions. Summary of the invention

[0004] In view of the defects in the prior art, the purpose of the present invention is to provide a GEO positioning system with an external encoder, aiming to achieve real-time positioning monitoring of the mobile unit and eliminate the traditional positioning deviation caused by transmission pair failure.

[0005] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solution:

[0006] Provided is a GEO positioning system with an external encoder, characterized in that it comprises: a mobile unit, a coding ruler, a motor, a transmission structure, an external encoder, and a control unit;

[0007] The code ruler is installed on the mobile unit, and the external encoder is installed on the conveying station, which can read the code ruler installed on the mobile unit to obtain its actual position information and transmit it to the control unit;

[0008] The motor is used to provide power and drive the transmission structure to operate;

[0009] The motor has a built-in encoder to monitor the speed and rotation angle of the motor spindle and transmit the data to the control unit for positioning judgment;

[0010] The transmission structure is used to transmit the rotational power of the motor to the mobile unit;

[0011] The control unit controls the movement of the mobile unit according to a preset control rule, wherein the preset control rule includes: when the value of the built-in encoder of the motor reaches a first preset range, and the value of the external encoder reaches a second preset range, it is determined that the mobile unit has moved into place at the current workstation, and a stop command is sent to the motor, the motor immediately stops with a brake, and the mobile unit stops conveying.

[0012] Preferably, the preset control rules also include:

[0013] When the position data fed back by the external encoder is within the preset deceleration range, the control unit sends a deceleration command to the motor to put the motor into deceleration mode.

[0014] Preferably, the preset control rules also include:

[0015] The deviation between the value of the built-in encoder of the motor and the value of the external encoder is calculated. When the deviation is greater than a preset alarm threshold, it is determined that a fault exists in the transmission structure and an alarm message is triggered.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The present invention adopts a mobile unit to install a coding ruler, and installs an external encoder at the GEO station to read the code value of the coding ruler to control the stop of the mobile unit, eliminating the monitoring blind area caused by the transmission pair problem in the traditional method, thereby ensuring the real-time monitoring of the position of the final white body and reducing the risk of quality or collision. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0019] Figure 1 The figure is a schematic diagram of the structure of the system according to the embodiment of the present invention.

[0020] The figure shows:

[0021] 1- Motor;

[0022] 2-External encoder;

[0023] 3- Transmission mechanism. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0026] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. In addition, all directional indications in this application (such as up, down, left, right, front, back, bottom...) are only used to explain the relative position relationship, movement, etc. between the components in a certain specific posture (as shown in the drawings). If the specific posture changes, the directional indication will also change accordingly.

[0027] Example

[0028] This embodiment provides a GEO positioning system with an external encoder, which is used to solve the positioning deviation problem caused by the accuracy problem of the motor and the transmission structure of the mobile unit when the traditional positioning of the mobile unit using the motor built-in encoder is realized.

[0029] Specifically, the system provided in this embodiment includes a mobile unit, a coding ruler, a motor 1 and a motor built-in encoder, a transmission structure 3, an external encoder 2, and a control unit. Among them, the structure of the motor 1, the external encoder 2, and the transmission structure 3 is as follows: Figure 1 As shown. The control unit is a PLC (Programmable Logic Controller) which controls the movement of the mobile unit according to preset control rules. The code ruler is installed on the mobile unit, and the external encoder 2 can read the value of the code ruler.

[0030] The motor 1 is used to provide power to drive the transmission structure to move the mobile unit along the conveying path. At the same time, the motor 1 has a built-in encoder to monitor the speed and rotation angle of the motor spindle and transmit the data to the PLC for positioning judgment.

[0031] The external encoder 2 is installed on the conveying station to directly measure the actual position of the mobile unit, provide accurate position feedback, and compensate for the positioning deviation caused by the error of the transmission mechanism. Specifically, the external encoder 2 reads the code ruler installed on the mobile unit to obtain its actual position information and transmits the data to the PLC in real time. Unlike the built-in encoder of the motor 1, which can only detect the rotation of the motor spindle, the external encoder 2 can directly reflect the actual position of the mobile unit, ensuring the accuracy and stability of positioning.

[0032] The transmission structure 3 is used to transmit the rotational power of the motor 1 to the mobile unit so that it moves along the conveying path.

[0033] When the mobile unit moves from the previous station to the current conveying station (GEO station), the motor 1 rotates, and the mobile unit is conveyed through the transmission mechanism 3. The PLC reads the value of the built-in encoder of the motor 1 and the value of the external encoder 2 in real time, and controls the movement of the mobile unit according to the preset control rules to achieve redundant positioning accuracy control guarantee. The preset control rules of the PLC are: when the value of the built-in encoder of the motor 1 reaches the first preset range, and the value of the external encoder 2 reaches the second preset range, it is judged that the mobile unit has moved into place at the current station, and a stop command is sent to the motor 1, and the motor 1 immediately stops with the brake, and the mobile unit stops conveying. Only when the value of the external encoder 2 and the value of the built-in encoder of the motor 1 reach the PLC setting range at the same time, the PLC judges that the mobile unit has moved into place at the current station, thereby realizing the GEO positioning of the mobile unit at the conveying station, and improving the station positioning accuracy and stability, thereby ensuring the high accuracy and reliability of the manufacturing process.

[0034] Furthermore, the preset control rules of the PLC may also include: when the position data fed back by the external encoder 2 is within the preset deceleration range, the PLC sends a deceleration instruction to the motor 1 to put the motor 1 into a deceleration mode, thereby preventing the mobile unit from stopping suddenly and rushing through the target position due to inertia.

[0035] In addition, the preset control rules of the PLC may also include: calculating the deviation between the value of the built-in encoder of the motor 1 and the value of the external encoder 2, and when the deviation is greater than the preset alarm threshold, judging that there is a fault in the transmission structure 3, and triggering an alarm message. Such a control method can timely detect possible faults in the transmission structure by monitoring the large deviation in the feedback data of the built-in encoder of the motor 1 and the external encoder 2, and remind the operation and maintenance personnel to check the transmission structure in time to prevent collision or equipment damage due to positioning errors.

[0036] The overall operation process of this system is as follows:

[0037] like Figure 1 As shown, when the roller bed of the previous station starts to transport the mobile unit to this station, the motor 1 of this station outputs rotation, and through the transmission mechanism 3, the transmission pairs of multiple transmission roller assemblies roll to drive the mobile unit to be transported to this station. During the movement, the built-in encoder of motor 1 reads the motor spindle speed and the external encoder 2 reads the encoder scale on the mobile unit. The external encoder value positioning method is mainly used, and the built-in encoder positioning method of motor 1 is auxiliary. When the encoder values ​​read by both in real time reach the range set by the PLC, the PLC determines that the mobile unit has moved into place at this station, and motor 1 immediately stops with a brake, and the mobile unit stops transporting.

[0038] This embodiment installs a coding ruler on the mobile unit and a matching encoder at the conveying station. While retaining the traditional motor built-in encoder positioning method, a positioning method for reading the mobile unit encoding value is added to achieve real-time positioning and ensure positioning accuracy. Two positioning method redundancies are added, and the positioning accuracy and reliability of the station are improved by mainly using an external positioning method, eliminating positioning problems caused by problems in the transmission structure of the motor and the mobile unit. By comparing the two positioning data, positioning deviations caused by the transmission structure can be discovered earlier, and major risks such as possible collisions and equipment damage can be eliminated by timely repairing the transmission mechanism.

[0039] The above describes the specific embodiments of the present invention. Based on the above description, relevant personnel can make various changes and modifications without departing from the technical concept of the present invention.

Claims

1. A GEO positioning system with an external encoder, characterized in that: include: Mobile unit, code ruler, motor, transmission structure, external encoder, control unit; The code ruler is installed on the mobile unit, and the external encoder is installed on the conveying station, which can read the code ruler installed on the mobile unit to obtain its actual position information and transmit it to the control unit; The motor is used to provide power and drive the transmission structure to operate; The motor has a built-in encoder to monitor the speed and rotation angle of the motor spindle and transmit the data to the control unit for positioning judgment; The transmission structure is used to transmit the rotational power of the motor to the mobile unit; The control unit controls the movement of the mobile unit according to a preset control rule, wherein the preset control rule includes: when the value of the built-in encoder of the motor reaches a first preset range, and the value of the external encoder reaches a second preset range, it is determined that the mobile unit has moved into place at the current workstation, and a stop command is sent to the motor, the motor immediately stops with a brake, and the mobile unit stops conveying.

2. A GEO positioning system with an external encoder as claimed in claim 1, characterized in that: The preset control rules also include: When the position data fed back by the external encoder is within the preset deceleration range, the control unit sends a deceleration command to the motor to put the motor into deceleration mode.

3. A GEO positioning system with an external encoder as claimed in claim 1, characterized in that: The preset control rules also include: The deviation between the value of the built-in encoder of the motor and the value of the external encoder is calculated. When the deviation is greater than a preset alarm threshold, it is determined that a fault exists in the transmission structure and an alarm message is triggered.

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