All-digital encoder train accurate positioning system of unhooking robot readjusting machine

Abstract

The invention belongs to the technical field of connectors specially suitable for railway vehicles, and particularly relates to an uncoupling robot reconditioning machine all-digital encoder train accurate positioning system which comprises a reconditioning machine body for driving a compartment to move and an uncoupling robot, and a digital encoder is fixedly mounted at the bottom of the reconditioning machine body. The digital encoder comprises an absolute value photoelectric encoder and a metal hub, the outer side of a rotating shaft of the absolute value photoelectric encoder is fixedly connected with the metal hub, the absolute value photoelectric encoder is installed on the readjusting machine body, and the metal hub rolls relative to the guide block; the positioning system further comprises a PLC control system, the digital encoder is connected with a CPU module of the PLC control system through a communication cable, a DO module of the PLC control system adjusts the power of a frequency converter of the readjusting machine through a control cable, the readjusting machine is used for pulling the whole column of heavy cars, accurate positioning is carried out at the unhooking position of the robot, the accuracy reaches + / -2 cm, and the positioning precision reaches + / -2 cm. The cost and the failure rate are reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of connectors specially suitable for railway vehicles, and in particular relates to a fully digital encoder train precision positioning system for a hook-off robot readjustment machine. Background Art

[0002] The unhooking robot is a mechanical arm used for unhooking train couplers by the tipping machine system. Currently, the unhooking robots produced domestically are limited by the large positioning error of the readjustment machine, with the positive and negative errors exceeding 1.5 meters. As a last resort, the robot arm needs to be designed with a seventh additional axis, that is, a mobile robot, so that the robot can actively find the gap between the carriages and perform secondary positioning through the robot. Secondary positioning will bring longer process time and lower work efficiency. The large active gap of the seventh axis reduces the positioning accuracy of the arm's tentacles. Currently, all the unhooking robots on the market are self-propelled mobile robots. Under the current situation of large positioning errors of the readjustment machine, secondary positioning of the robot not only increases the unloading process time, but also increases the manufacturing cost, and the failure rate also increases accordingly. Summary of the invention

[0003] To solve the problems raised in the above background technology. The present invention provides a fully digital encoder train precise positioning system for a hook-off robot re-adjuster, which uses and utilizes the re-adjuster to tow the entire train of heavy vehicles and accurately locates the robot at the unhooking position, with an accuracy of plus or minus 2 centimeters, reducing costs and failure rates.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a fully digital encoder train precise positioning system for a hook-removing robot and a re-adjusting machine, comprising a re-adjusting machine body for driving the carriage to move and a hook-removing robot, a digital encoder is fixedly installed at the bottom of the re-adjusting machine body, the digital encoder comprises an absolute value photoelectric encoder and a metal hub, the outer side of the rotating shaft of the absolute value photoelectric encoder is fixedly connected with the metal hub, the absolute value photoelectric encoder is installed on the re-adjusting machine body, and the metal hub rolls relative to the guide block;

[0005] The positioning system also includes a PLC control system. The digital encoder is connected to the CPU module of the PLC control system through a communication cable. The DO module of the PLC control system adjusts the power of the frequency converter of the readjusting machine through the control cable.

[0006] As a preferred embodiment of the unhooking robot readjustment machine full digital encoder train precision positioning system of the present invention, the number of digital encoders is two.

[0007] As a preferred embodiment of the fully digital encoder train precision positioning system of a hook-unhooking robot readjustment machine of the present invention, the digital encoder also includes a rubber friction wheel, the outer surface of the metal wheel hub is fixedly connected to the rubber friction wheel, and the metal wheel hub is rollingly connected to the guide block through the rubber friction wheel.

[0008] As a preferred embodiment of a fully digital encoder train precision positioning system for a hook-unhooking robot readjustment machine of the present invention, the digital encoder also includes a movable block, a fixed block, a guide rod and a spring device. The bottom of the movable block is fixedly connected to the outer surface of the absolute value photoelectric encoder, the inner side of the movable block is slidably connected to the guide rod, the top of the guide rod is fixedly connected to the fixed block, the top of the fixed block is fixedly connected to the bottom of the readjustment machine body, and a spring device is fixedly connected between the outer side of the bottom end of the fixed block and the outer side of the top end of the movable block.

[0009] As a preferred embodiment of the unhooking robot readjustment machine full digital encoder train precision positioning system of the present invention, the unhooking robot is fixed on the supporting base through a base plate, and two positioning lasers are fixedly connected to the base plate. The distance between the two positioning lasers is smaller than the distance between the two carriages, and the two positioning lasers are respectively connected to the DO module of the PLC control system through control cables.

[0010] Compared with the prior art, the beneficial effects of the present invention are: a digital encoder and a positioning laser are used to assist the readjustment machine in one-time positioning, and the positioning accuracy is improved to plus or minus 2 centimeters, that is, the readjustment machine is used to tow the entire train of heavy vehicles, and accurately positioned at the robot unhooking position, with an accuracy of plus or minus 2 centimeters, which fully meets the vehicle unhooking gap positioning requirements of the fixed unhooking robot, eliminates the need to add a seventh-axis device to the unhooking robot, improves the unhooking efficiency of the unhooking robot, saves the cost increase caused by the moving axis of the unhooking robot, and reduces the tentacle positioning error caused by the seventh axis. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0012] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0013] Figure 2 It is a structural schematic diagram of the main body of the readjustment machine in the present invention;

[0014] Figure 3 For the present invention Figure 2 Schematic diagram of the enlarged structure at A;

[0015] Figure 4 It is a structural schematic diagram of the digital encoder in the present invention;

[0016] Figure 5 It is a top view of the overall structure of the present invention;

[0017] Figure 6 A schematic diagram of the relative position of the positioning laser in the present invention;

[0018] Figure 7 This is a schematic diagram of a first detection state of a positioning laser in the present invention;

[0019] Figure 8 It is a schematic diagram of a second detection state of the positioning laser in the present invention;

[0020] Fig. 9 It is a schematic diagram of a third detection state of the positioning laser in the present invention;

[0021] Fig.10 It is a structural schematic diagram of the control logic in the present invention;

[0022] In the figure:

[0023] 1. Carriage; 2. Re-adjusting machine body; 3. Shunting arm; 4. Guide block; 5. Digital encoder; 51. Absolute photoelectric encoder; 52. Metal wheel hub; 53. Rubber friction wheel; 54. Movable block; 55. Fixed block; 56. Guide rod; 57. Spring device; 6. Hook-removing robot; 61. Bottom plate; 7. Positioning laser; 8. PLC control system; 9. Re-adjusting machine frequency converter. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] like Figure 1-Figure 10 As shown:

[0026] A hook-removing robot 6 re-adjusting machine full digital encoder 5 train precise positioning system, comprising a re-adjusting machine body 2 driving a carriage 1 to move and a hook-removing robot 6, a digital encoder 5 is fixedly installed at the bottom of the re-adjusting machine body 2, the digital encoder 5 comprises an absolute value photoelectric encoder 51 and a metal hub 52, the outer side of the rotating shaft of the absolute value photoelectric encoder 51 is fixedly connected with the metal hub 52, the absolute value photoelectric encoder 51 is installed on the re-adjusting machine body 2, and the metal hub 52 rolls relative to the guide block 4;

[0027] The positioning system also includes a PLC control system 8. The digital encoder 5 is connected to the CPU module of the PLC control system 8 via a communication cable. The DO module of the PLC control system 8 adjusts the power of the readjustment machine inverter 9 via the control cable.

[0028] In this embodiment, the unhooking robot 6 is a mechanical arm used for unhooking the train coupler by the tipping machine system. The unhooking robots 6 currently produced in China are limited by the problem of large positioning errors of the readjustment machine, with positive and negative errors exceeding 1.5 meters. As a last resort, the mechanical arm needs to be designed to use the seventh additional axis, that is, a mobile robot, so that the robot can actively find the gap between the carriages 1 and perform secondary positioning through the robot. The secondary positioning will bring a longer process time and lower work efficiency. The seventh axis activity gap is large, which reduces the positioning accuracy of the arm tentacles. At present, the unhooking robots 6 on the market all use self-propelled mobile robots. Under the current situation of large positioning errors of the readjustment machine, the robot is required to perform secondary positioning, which not only increases the unloading process time, but also increases the manufacturing cost, and the failure rate also increases accordingly.

[0029] The present invention uses a digital encoder 5 and a positioning laser 7 to assist the readjustment machine in one-time positioning, and improves the positioning accuracy to plus or minus 2 centimeters, that is, the readjustment machine is used to tow the entire train of heavy vehicles, and accurately positions the robot at the unhooking position, with an accuracy of plus or minus 2 centimeters, which fully meets the positioning requirements of the vehicle unhooking gap of the fixed unhooking robot 6, eliminates the need to add a seventh axis device to the unhooking robot 6, improves the unhooking efficiency of the unhooking robot 6, saves the cost increase caused by the moving axis of the unhooking robot 6, and reduces the tentacle positioning error caused by the seventh axis;

[0030] The precise positioning system of the present invention is applied to the unhooking robot 6 system, which is suitable for the gap between the two carriages 1 to be not less than 60 cm, so as to facilitate the operation of the robot arm. The whole train of heavy cars is towed by the heavy-shunting machine body 2 through the shunting arm 3 to the unhooking position, and is positioned by the digital encoder 5 and the positioning laser 7. The PLC control system 8 realizes the precise positioning of the whole train of cars 1 by low-frequency and pulse width modulation of the heavy-shunting machine inverter 9; pulse width modulation is a technology that controls the output voltage or current by changing the duty cycle of the pulse signal. In the heavy-shunting machine inverter 9, the PLC control system 8 controls the average value of the inverter output voltage by adjusting the pulse width, that is, changing the ratio of the duration of the high level in each pulse cycle to the entire cycle, thereby controlling the speed and torque of the motor. In the precise positioning process, the fine speed regulation of the heavy-shunting machine motor can be achieved by precisely adjusting the pulse width. For example, when it is necessary to fine-tune the position of the heavy-shunting machine body 2, the PLC control system 8 can dynamically adjust the pulse width according to the position information fed back by the digital encoder 5 and the positioning laser 7, so that the motor speed changes slightly, thereby realizing the precise positioning of the whole train car.

[0031] When the realignment machine body 2 needs to accurately position the entire train carriage 1, the PLC control system will control the realignment machine inverter 9 to output a low-frequency signal to the motor of the realignment machine. When running at low frequency, the motor speed is reduced, causing the traction speed of the realignment machine to slow down accordingly, thereby being able to more accurately control the moving distance and position of the realignment machine and achieve precise positioning.

[0032] Currently in the field of automatic hook-removing robots 6, the positioning error of the readjustment machines exceeds plus or minus 5 meters. Robot design manufacturers all adopt a self-propelled solution to perform secondary positioning of the robots, and have not fully adopted the technical solution of direct and precise positioning of the readjustment machines. The digital encoder 5 can detect the displacement length of the readjustment machine body 2. When the readjustment machine body 2 moves, it will drive the digital encoder 5 to move together. Therefore, when the digital encoder 5 moves, the metal wheel hub 52 will roll, and the number of rotations of the metal wheel hub 52 will be detected by the absolute value photoelectric encoder 51 and calculated into the distance moved by the readjustment machine body 2 through the PLC control system 8.

[0033] In an optional embodiment, the number of digital encoders 5 is two, and dual sets of digital encoders 5 are installed. The two digital encoders 5 are redundantly controlled. When any one encoder fails, the other encoder can continue to work normally, ensuring that the positioning function is not affected, avoiding the inability to accurately position the entire unhooking robot 6 system due to a single encoder failure, thereby improving the reliability and stability of the system and reducing downtime due to equipment failure. Moreover, even if one encoder has data deviation or error, the PLC control system 8 can identify the abnormal data and use the data of the normal encoder by comparing and analyzing the data of the two encoders, effectively reducing the risk of positioning errors caused by encoder failure or data abnormality. The two digital encoders 5 can complement and correct each other during work. Due to the installation position and working environment Due to the influence of factors such as the environment, a single encoder may have a certain measurement error. By fusing the data of the two sets of encoders, the PLC control system can analyze and calculate the measurement data more accurately, eliminate or reduce the error, and thus improve the positioning accuracy. When the system has a positioning problem, the technician can quickly determine whether it is a fault of the encoder itself or other system components by comparing the data of the two sets of encoders and the relevant records in the PLC control system 8, narrowing the scope of troubleshooting, improving the efficiency of fault diagnosis, and reducing maintenance costs and time. Without stopping the machine, one of the encoders can be maintained or replaced online. Since the redundant encoder is working normally, the positioning function of the system will not be interrupted, and the technician can repair or replace the faulty encoder at an appropriate time, thereby improving the maintainability and availability of the equipment.

[0034] In an optional embodiment, the digital encoder 5 also includes a rubber friction wheel 53, and the outer surface of the metal hub 52 is fixedly connected to the rubber friction wheel 53. The metal hub 52 is rollingly connected to the guide block 4 through the rubber friction wheel 53. By setting the rubber friction wheel 53, the friction between the metal hub 52 and the guide block 4 can be improved to avoid sliding friction, thereby affecting the accuracy of the data.

[0035] In an optional embodiment, the digital encoder 5 further includes a movable block 54, a fixed block 55, a guide rod 56 and a spring device 57, the bottom of the movable block 54 is fixedly connected to the outer surface of the absolute value photoelectric encoder 51, the inner side of the movable block 54 is slidably connected to the guide rod 56, the top of the guide rod 56 is fixedly connected to the fixed block 55, the top of the fixed block 55 is fixedly connected to the bottom of the reset machine body 2, and the spring device 57 is fixedly connected between the outer side of the bottom end of the fixed block 55 and the outer side of the top end of the movable block 54;

[0036] In this embodiment, affected by the working environment, coal blocks are easily attached to the guide block 4. If the position of the guide block 4 is fixed relative to the position of the resetting machine body 2 and only rotates at the relative position, when the rubber friction wheel 53 rolls on the guide block 4, the rubber friction wheel 53 will be squeezed and damaged. When the resetting machine body 2 moves, the vibration of the resetting machine body 2 and the microscopic instability during movement may also easily cause the rubber friction wheel 53 to be out of contact with the guide block 4. Therefore, it is necessary to install a spring device 57 to solve this problem.

[0037] The spring device 57 exerts elastic force on the movable block 54, and the movable block 54 exerts a downward force on the absolute value photoelectric encoder 51 and then on the metal hub 52 and the rubber friction wheel 53, so that the rubber friction wheel 53 acts on the guide block 4 with a certain elastic force, so that when foreign matter is attached to the guide block 4, the rubber friction wheel 53 can better pass over the foreign matter and ensure the rotation stability of the rubber friction wheel 53;

[0038] The spring device 57 can be an elastic metal body that only provides elastic force, or it can be a strain gauge spring device 57, a linear variable differential transformer (LVDT) spring device 57, a photoelectric spring device 57, a capacitive spring device 57, or a magnetostrictive spring device 57. These devices all have a feature that when the spring device 57 undergoes elastic deformation, the deformation of the spring device 57 can be converted into an electrical signal, thereby determining the deformation of the spring. After the rubber friction wheel 53 has rolled over foreign matter for multiple times, the number of rotations of the rubber friction wheel 53 and the calculated distance will deviate. This deviation will increase with the increase in the number of rolling times. There may also be a situation where the foreign matter is cleared after rolling over the foreign matter, ultimately resulting in a deviation between the walking distance calculated based on the number of rotations of the rubber friction wheel 53 and the actual distance. By detecting the change in elastic force through the spring device 57, it is possible to timely understand whether the factors causing the deviation have occurred, which is convenient for timely cleaning of foreign matter or calibration of the digital encoder 5. The output signal of the spring device 57 can be connected to the control host in a wireless manner, which is convenient for observing the numerical changes output by the spring device 57.

[0039] In an optional embodiment, the unhooking robot 6 is fixed on the supporting base through a base plate 61, and two positioning lasers 7 are fixedly connected to the base plate 61. The distance between the two positioning lasers 7 is smaller than the distance between the two carriages 1. The two positioning lasers 7 are respectively connected to the DO module of the PLC control system 8 through control cables.

[0040] In this embodiment: the installed positioning laser 7 is used to monitor the position of the carriage 1. The positioning laser 7 is installed at the unhooking robot 6. The mounting bracket is 2.3 meters above the ground and between 1 meter and 2 meters away from the side of the carriage 1. A total of two positioning lasers 7 are installed. The two positioning lasers 7 are on the same horizontal plane with a horizontal spacing of 50 cm. The positioning laser 7 in the pulling direction is used to issue a positioning command for the carriage 1. The positioning laser 7 in the receiving direction is used for position correction. The lasers emitted by the two digital encoders 5 are parallel to each other and perpendicular to the side of the carriage 1 (such as Figure 6 As shown), it communicates with the PLC control system 8 of the tipping machine system through a communication cable, transmits data to the PLC control system 8, and converts the data into an actual walking distance value; two positioning lasers 7 are connected to the digital input module (DI module) through a control cable, and the readjustment machine inverter 9 is uniformly controlled by the PLC control system 8. Through the vehicle type judgment logic, the current vehicle type is detected, and the length of the car 1 or the overall length of multiple cars 1 is calculated. The readjustment machine drives the inverter to run at high speed. Through the walking distance calculation, when the car 1 walks to the target unhooking position and there is 2 meters left from the unhooking robot 6, the inverter is controlled to perform a 2-stage deceleration, and the positioning laser 7 in the towing direction is used for primary Positioning is used to detect the edge of the carriage 1. After the positioning laser 7 detects the outer surface of the carriage 1 and crosses the edge of the carriage 1, the distance detected by the positioning laser 7 will suddenly increase. At this time, the inverter is driven to reverse and a pulse width modulation command is issued to control the inverter to enter the creeping mode. The positioning laser 7 in the direction of the car is fine-tuned. After the distance detected by the positioning laser 7 suddenly increases, it means that the carriage 1 has moved to the target position, and the traction of the carriage 1 by the readjustment machine body 2 can be stopped to stop the movement of the carriage 1. Then the unhooking robot 6 can unhook. Since the distance between the two carriages 1 is 60 cm and the distance between the two positioning lasers 7 is 50 cm, the detection accuracy is relatively high.

[0041] like Figure 6-Figure 9 As shown, assuming that the carriage 1 moves from left to right, the positioning laser 7 on the left is the positioning laser 7 in the pulling direction, and the positioning laser 7 on the right is the positioning laser 7 in the receiving direction;

[0042] In order to further improve the detection accuracy of the positioning laser 7, the two positioning lasers 7 are not on the same horizontal plane, and the two positioning lasers 7 are symmetrically tilted, that is, the lasers emitted by the two positioning lasers 7 cross each other in the projection direction, such as Figure 7-Figure 9 As shown, when the carriage 1 moves from left to right, the distance detected by the positioning laser 7 on the right side will suddenly increase, while the distance detected by the positioning laser 7 on the left side will remain unchanged as a whole. As the carriage 1 continues to move, the distance detected by the positioning laser 7 on the left side also begins to increase. At the same time, the distance detected by the positioning laser 7 on the right side gradually decreases until the distances detected by the two positioning lasers 7 are the same. When the distances detected by the two positioning lasers 7 are the same, the movement of the carriage 1 is stopped immediately, and the unhooking robot 6 will be more accurately located between the two carriages 1.

[0043] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A hook-removing robot and realignment machine full digital encoder train precision positioning system, comprising a realignment machine body (2) for driving a carriage (1) to move and a hook-removing robot (6), characterized in that: A digital encoder (5) is fixedly mounted on the bottom of the readjustment machine body (2), the digital encoder (5) comprising an absolute value photoelectric encoder (51) and a metal hub (52), the metal hub (52) being fixedly connected to the outer side of the rotating shaft of the absolute value photoelectric encoder (51), the absolute value photoelectric encoder (51) being mounted on the readjustment machine body (2), and the metal hub (52) rolling relative to the guide block (4); The positioning system also includes a PLC control system (8), the digital encoder (5) is connected to the CPU module of the PLC control system (8) via a communication cable, and the DO module of the PLC control system (8) adjusts the power of the readjustment machine inverter (9) via the control cable.

2. The hook-removing robot (6) readjusting machine full digital encoder (5) train precise positioning system according to claim 1 is characterized by: The number of digital encoders (5) is two.

3. The unhooking robot (6) readjustment machine full digital encoder (5) train precise positioning system according to claim 1 is characterized by: The digital encoder (5) further comprises a rubber friction wheel (53), the outer surface of the metal hub (52) is fixedly connected with the rubber friction wheel (53), and the metal hub (52) is rollingly connected with the guide block (4) via the rubber friction wheel (53).

4. The hook-removing robot (6) readjustment machine full digital encoder (5) train precise positioning system according to claim 1 is characterized by: The digital encoder (5) also includes a movable block (54), a fixed block (55), a guide rod (56) and a spring device (57); the bottom of the movable block (54) is fixedly connected to the outer surface of the absolute value photoelectric encoder (51); the inner side of the movable block (54) is slidably connected to the guide rod (56); the top of the guide rod (56) is fixedly connected to the fixed block (55); the top of the fixed block (55) is fixedly connected to the bottom of the readjustment machine body (2); and the spring device (57) is fixedly connected between the outer side of the bottom end of the fixed block (55) and the outer side of the top end of the movable block (54).

5. The hook-removing robot (6) readjusting machine full digital encoder (5) train precise positioning system according to claim 1 is characterized by: The hook-removing robot (6) is fixed on a supporting base through a base plate (61), and two positioning lasers (7) are fixedly connected to the base plate (61). The distance between the two positioning lasers (7) is smaller than the distance between the two carriages (1). The two positioning lasers (7) are respectively connected to the DO module of the PLC control system (8) through control cables.

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