Full digital encoder train precise positioning system for a hook-unhooking robot readjusting machine

Abstract

The present invention belongs to the technical field of connectors specifically applicable to railway vehicles, and in particular to a fully digital encoder train precise positioning system for a hook-unhooking robot reconditioning machine, which includes a reconditioning machine body for driving the carriage to move and a hook-unhooking robot. A digital encoder is fixedly installed at the bottom of the reconditioning machine body. The digital encoder includes 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 reconditioning machine body, and the metal hub rolls relative to the guide block. The positioning system further 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 reconditioning machine frequency converter through a control cable, uses and utilizes the reconditioning machine to tow the whole train of heavy vehicles, and performs precise positioning at the robot hook-unhooking position, with the precision reaching plus or minus 2 centimeters, reducing costs and failure rates.

Description

Technical Field

[0001] The present invention belongs to the technical field of connectors specifically applicable to railway vehicles, and particularly relates to a full digital encoder train precise positioning system for a hook-removing robot re-regulator. Background Art

[0002] The hook-removing robot is a robotic arm used for unhooking the train coupler in a dumper system. Currently, the hook-removing robots produced in China are restricted by the large positioning error of the re-regulator, with a positive and negative error exceeding 1.5 meters. Therefore, the robotic arm has to be designed to use a seventh additional axis, that is, a mobile robot, to let the robot actively search for the carriage gap and perform secondary positioning through the robot. The secondary positioning will bring a longer process time and lower work efficiency. The seventh axis has a relatively large movement gap, reducing the positioning accuracy of the arm's touch head. Currently, all the hook-removing robots on the market adopt self-propelled mobile robots. In the current situation of large positioning errors of the re-regulator, performing secondary positioning of the robot not only increases the duration of the unloading process, 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 art, the present invention provides a full digital encoder train precise positioning system for a hook-removing robot re-regulator, which uses and utilizes the re-regulator to tow a whole train of loaded cars and performs precise positioning at the hook-removing position of the robot, with a precision reaching plus or minus 2 centimeters, reducing costs and failure rates.

[0004] To achieve the above object, the present invention provides the following technical solution: A full digital encoder train precise positioning system for a hook-removing robot re-regulator, including a re-regulator body for driving the carriage to move and a hook-removing robot. A digital encoder is fixedly installed at the bottom of the re-regulator body. The digital encoder includes an absolute photoelectric encoder and a metal hub. A metal hub is fixedly connected to the outside of the rotating shaft of the absolute photoelectric encoder. The absolute photoelectric encoder is installed on the re-regulator body, and the metal hub rolls relative to the guide block.

[0005] The positioning system further 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 re-regulator frequency converter through a control cable.

[0006] Preferably, for a full digital encoder train precise positioning system for a hook-removing robot re-regulator of the present invention, the number of digital encoders is two.

[0007] Preferably, for a full digital encoder train precise positioning system for a hook-removing robot re-regulator of the present invention, the digital encoder further includes a rubber friction wheel. A rubber friction wheel is fixedly connected to the outer surface of the metal hub, and the metal hub is in rolling connection with the guide block through the rubber friction wheel.

[0008] Preferably, in the all-digital encoder train precise positioning system of the hook-removing robot reconditioner of the present invention, the digital encoder further 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 photoelectric encoder. A guide rod is slidably connected to the inner side of the movable block. 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 reconditioner body. 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] Preferably, in the all-digital encoder train precise positioning system of the hook-removing robot reconditioner of the present invention, the hook-removing robot is fixed on the bearing base through a bottom plate. Two positioning lasers are fixedly connected to the bottom plate. The distance between the two positioning lasers is less than the distance between two carriages. 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 as follows: The digital encoder and the positioning laser jointly assist the reconditioner for one-time positioning, and the positioning accuracy is improved to plus or minus 2 cm. That is, the reconditioner is used to tow a whole train of heavy vehicles and perform precise positioning at the hook-removing position of the robot. The accuracy reaches plus or minus 2 cm, which fully meets the positioning requirements of the hook clearance of the fixed hook-removing robot, eliminates the need for the hook-removing robot to add a seventh-axis device, improves the hook-removing efficiency of the hook-removing robot, saves the cost increase brought by the moving axis of the hook-removing robot, and reduces the touch position error brought by the seventh axis. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0013] Figure 2 is a schematic diagram of the structure of the reconditioner body in the present invention;

[0014] Figure 3 In the present invention Figure 2 is an enlarged schematic diagram of part A;

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

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

[0017] Figure 6 is a schematic diagram of the relative positions of the positioning lasers in the present invention;

[0018] Figure 7 Schematic diagram of the first detection state of the positioning laser in the present invention;

[0019] Figure 8 Schematic diagram of the second detection state of the positioning laser in the present invention;

[0020] Figure 9 Schematic diagram of the third detection state of the positioning laser in the present invention;

[0021] Figure 10 Schematic diagram of the control logic structure in the present invention;

[0022] In the figure:

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

[0024] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts belong to the protection scope of the present invention.

[0025] As Figures 1-10 shown:

[0026] A train precise positioning system for a hook - unhooking robot 6 re - adjustment machine full - digital encoder 5 includes a main body 2 of the re - adjustment machine for driving the carriage 1 to move and a hook - unhooking robot 6. A digital encoder 5 is fixedly installed at the bottom of the main body 2 of the re - adjustment machine. The digital encoder 5 includes an absolute value photoelectric encoder 51 and a metal hub 52. A metal hub 52 is fixedly connected to the outside of the rotating shaft of the absolute value photoelectric encoder 51. The absolute value photoelectric encoder 51 is installed on the main body 2 of the re - adjustment machine, and the metal hub 52 rolls relative to the guide block 4;

[0027] The positioning system further includes a PLC control system 8. The digital encoder 5 is connected to the CPU module of the PLC control system 8 through a communication cable, and the DO module of the PLC control system 8 adjusts the power of the re - adjustment machine frequency converter 9 through a 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 unhooking robots 6, the positioning error of the reset machine exceeds plus or minus 5 meters. Robot design manufacturers all adopt the self-walking scheme to perform secondary positioning of the robot, and do not fully adopt the technical scheme of directly and accurately positioning with the reset machine. The digital encoder 5 can detect the displacement length of the reset machine body 2. When the reset machine body 2 moves, it will drive the digital encoder 5 to move together. Therefore, during the movement of the digital encoder 5, the metal hub 52 will roll, and the number of turns of the rotation of the metal hub 52 will be detected by the absolute value photoelectric encoder 51, and the distance of the movement of the reset machine body 2 will be calculated through the PLC control system 8.

[0033] In an alternative embodiment, the number of digital encoders 5 is two. Two sets of digital encoders 5 are installed and controlled redundantly and complementarily. When any one of the encoders fails, the other encoder can continue to work normally, ensuring that the positioning function is not affected, avoiding the situation that the entire unhooking robot 6 system cannot be accurately positioned due to the failure of a single encoder, thereby improving the reliability and stability of the system, reducing the downtime caused by equipment failures. Moreover, even if one encoder has data deviation or error, the PLC control system 8 can identify the abnormal data and adopt 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 failures or data anomalies. The two digital encoders 5 can complement and correct each other during the working process. Due to the influence of factors such as the installation position and working environment, a single encoder may have a certain measurement error. Through the fusion processing of 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, thereby improving the positioning accuracy. When there is a positioning problem in the system, technicians can quickly judge whether it is a problem with 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 fault troubleshooting, improving the fault diagnosis efficiency, reducing the maintenance cost and time. Without shutting down the machine, one of the encoders can be maintained or replaced online. Since there is a redundant encoder working normally, the positioning function of the system will not be interrupted, and technicians can repair or replace the faulty encoder at an appropriate time, improving the maintainability and usability of the equipment.

[0034] In an alternative embodiment, the digital encoder 5 further includes a rubber friction wheel 53. The outer surface of the metal hub 52 is fixedly connected with the rubber friction wheel 53. The metal hub 52 is in rolling connection with the guide block 4 through the rubber friction wheel 53. By setting the rubber friction wheel 53, the friction force between the metal hub 52 and the guide block 4 can be increased, avoiding the occurrence of sliding friction, which may affect the accuracy of the data.

[0035] In an alternative 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 optical encoder 51. A guide rod 56 is slidably connected to the inner side of the movable block 54. The top of the guide rod 56 is fixedly connected to the fixed block 55. The top end of the fixed block 55 is fixedly connected to the bottom of the reset machine body 2. A 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 likely to adhere to the guide block 4. If the position of the guide block 4 is fixed relative to the position of the reset 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 damaged by extrusion. When the reset machine body 2 moves, the vibration of the reset machine body 2 and the microscopic instability during movement are also likely to cause the rubber friction wheel 53 not to contact the guide block 4. Therefore, a spring device 57 needs to be installed to solve this problem;

[0037] The spring device 57 will apply an elastic force to the movable block 54. The movable block 54 will apply a downward force to the absolute value optical encoder 51 and then to 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. Thus, when foreign objects adhere to the guide block 4, the rubber friction wheel 53 can better cross the foreign objects and can ensure the rotational stability of the rubber friction wheel 53;

[0038] The spring device 57 can be an elastic metal body that only provides elastic force, or a strain gauge type spring device 57 or a linear variable differential transformer (LVDT) type spring device 57 or an optoelectronic type spring device 57 or a capacitive type spring device 57 or a magnetostrictive type spring device 57. These devices all have a characteristic that when the spring device 57 undergoes elastic deformation, the deformation amount of the spring device 57 can be converted into an electrical signal to determine the deformation amount of the spring. When the rubber friction wheel 53 rolls over foreign objects multiple times, there will be a deviation between the number of rotations of the rubber friction wheel 53 and the calculated distance. This deviation will increase with the increase in the number of rolling times. After rolling over foreign objects, the foreign objects may be cleaned up. Eventually, there will be a deviation between the traveling distance calculated based on the number of rotations of the rubber friction wheel 53 and the actual distance. By detecting the change in the elastic force of the spring device 57, it is possible to timely understand whether the factors causing the deviation occur, which is convenient for timely cleaning of foreign objects or calibration of the digital encoder 5. The output signal of the spring device 57 can be connected to the control host wirelessly to facilitate observing the numerical change of the output of the spring device 57.

[0039] In an alternative embodiment, the uncoupling robot 6 is fixed to the carrying base through the bottom plate 61. Two positioning lasers 7 are fixedly connected to the bottom plate 61. The distance between the two positioning lasers 7 is less 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 lasers 7 are used to monitor the position of the carriage 1. The positioning lasers 7 are installed at the uncoupling robot 6. The installation bracket is 2.3 meters above the ground and is 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, and the horizontal distance is 50 centimeters. The positioning laser 7 in the car-pulling direction is used to issue a carriage 1 positioning command, and the positioning laser 7 in the car-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 (as Figure 6 shown). Through the communication cable, it communicates with the PLC control system 8 of the dumper system, and transmits the data to the PLC control system 8, and the data is converted into the actual walking distance value; the two positioning lasers 7 are connected to the digital input module (DI module) through the control cable. The reclaimer frequency converter 9 is uniformly controlled by the PLC control system 8. Through the vehicle type judgment logic, the current vehicle type is detected, the length of the carriage 1 or the overall length of multiple carriages 1 is calculated. The reclaimer drive frequency converter runs at high speed. Through the walking distance calculation, when the carriage 1 walks to a position 2 meters away from the uncoupling robot 6 at the target uncoupling position, the frequency converter is controlled to perform secondary deceleration. The positioning laser 7 in the car-pulling direction is used for primary positioning to detect the edge of the carriage 1. After the positioning laser 7 detects from the outer surface of the carriage 1 to crossing the edge of the carriage 1, the detected distance of the positioning laser 7 will suddenly increase. At this time, the drive frequency converter is reversed, and a pulse width modulation command is issued to control the frequency converter to enter the creep mode. The positioning laser 7 in the car-receiving direction is used for fine positioning. After the detected distance of this 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 reclaimer body 2 can be stopped, so that the carriage 1 stops moving. Then the uncoupling robot 6 can perform the uncoupling work. Since the distance between the two carriages 1 is 60 centimeters and the distance between the two positioning lasers 7 is 50 centimeters, the detection accuracy is relatively high;

[0041] As Figures 6-9 shown, assuming that the carriage 1 moves from left to right, the left positioning laser 7 is the positioning laser 7 in the car-pulling direction, and the right positioning laser 7 is the positioning laser 7 in the car-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 inclined, that is, the lasers emitted by the two positioning lasers 7 intersect with each other in the projection direction, asFigures 7-9 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 remains unchanged as a whole. As the carriage 1 continues to move, the distance detected by the positioning laser 7 on the left side also starts 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 immediately stopped. At this time, the uncoupling robot 6 will be more precisely located at the position between the two carriages 1.

[0043] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within 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) through a communication cable, and the DO module of the PLC control system (8) adjusts the power of the resetting machine inverter (9) through the control cable; The digital encoder (5) further comprises 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); The hook-removing robot (6) is fixed on a supporting base via 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 a DO module of a PLC control system (8) via a control cable.

2. The fully digital encoder train precise positioning system for unhooking robot readjustment machine according to claim 1 is characterized by: The number of digital encoders (5) is two.

3. The fully digital encoder train precise positioning system for unhooking robot readjustment machine 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 to the guide block (4) via the rubber friction wheel (53).

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