Load simulation system based on permanent magnet coupling

Abstract

The application relates to a load simulation system, in particular to a load simulation system based on a permanent magnet coupling, and belongs to the technical field of simulation. The load simulation system comprises a loading motor, a first tachometer, a permanent magnet coupling, a torque sensor, a second tachometer, a servo motor, an air gap adjusting device, an air gap spacing displacement sensor, a rotational speed difference signal generator, a torque error signal generator, a rotational speed difference solver, a loading motor rotational speed controller, a load / rotational speed converter, a rotational speed / air gap converter, an air gap error signal generator and an air gap adjusting controller. The load simulation system and the loaded system transmit torque through the force between the magnetic fields in the permanent magnet coupling, realize non-contact energy transmission, and can control the output load torque in real time according to the load simulation demand. The application adopts the permanent magnet coupling, the structure of which is simple and low in cost, and the permanent magnet coupling is easier to maintain and maintain; in addition, the permanent magnet coupling realizes non-contact energy transmission and saves energy.

Description

Technical Field

[0001] This invention relates to a load simulation system, specifically a load simulation system based on a permanent magnet coupling, and belongs to the field of simulation technology. Background Technology

[0002] Load simulation is a hardware-in-the-loop (HIL) experimental technique used to simulate various mechanical loads, capable of simulating the torque load required by the loaded object. This technology is widely used in military and civilian fields such as ship steering gear load simulation, marine steam valve opening and closing force load simulation, and automobile flywheel test load simulation. Furthermore, with the advancement of my country's equipment manufacturing industry, its application areas are gradually expanding.

[0003] In reality, some mechanical equipment operates smoothly and regularly, therefore, load simulation requires relatively gentle simulated loads. Examples include horizontal directional drilling rigs, auger pile drivers, and rotary drilling rigs. Taking horizontal directional drilling rigs as an example, they are construction machines that lay various underground utilities (pipelines, cables, etc.) without excavating the ground surface. They are widely used in the construction of flexible pipelines for water supply, electricity, telecommunications, natural gas, coal gas, and oil. A horizontal directional drilling rig load simulation system refers to a system that uses simulation devices to simulate the different load torques experienced by the horizontal directional drilling rig during actual construction, in order to evaluate and optimize its performance and stability. Specifically, it can simulate torque loads under various working conditions, such as load conditions under different speeds and power outputs. By simulating these load torques, parameters such as the drilling rig's output power, speed, and torque can be tested, and the performance and stability of the horizontal directional drilling rig can be evaluated through the testing and analysis of these parameters.

[0004] In existing technologies, electro-hydraulic load simulation systems are complex and expensive. Servo valves suffer from significant throttling losses and high energy consumption under high flow and high power conditions. Furthermore, some mechanical equipment currently uses magnetic particle brakes for load simulation; however, due to the continuous friction between the brake plate and brake wheel during operation, wear and thermal damage are unavoidable, and the magnetic powder gradually depletes. This necessitates replacement with new magnetic powder, resulting in a relatively short lifespan for magnetic particle brakes and a high frequency of replacement, thus increasing maintenance costs. Therefore, a more economical and reliable new load simulation system is needed. Summary of the Invention

[0005] To address the problems of complex structure and high cost in current load simulation systems, this invention designs a load simulation system based on a permanent magnet coupling. Firstly, it employs a permanent magnet coupling, which is simple in structure, low in cost, and easier to maintain and service. Secondly, the permanent magnet coupling enables non-contact energy transfer, saving energy and reducing consumption. Then, when the load exceeds a set maximum value, this invention can quickly reduce the load torque by widening the air gap of the permanent magnet coupling, thus providing overload protection for the system. Furthermore, it can achieve soft start, reduce starting current, reduce mechanical shock, and extend the system's service life. Since permanent magnet couplings can transmit large amounts of power and torque, this invention is suitable for most mechanical equipment requiring smooth loading of load torque.

[0006] The technical solution of this invention is: a load simulation system based on a permanent magnet coupling, comprising a loading motor, a first tachometer, a permanent magnet coupling, a torque sensor, a second tachometer, a servo motor, an air gap adjustment device, an air gap displacement sensor, a speed difference signal generator, a torque error signal generator, a speed difference solver, a loading motor speed controller, a load / speed converter, a speed / air gap converter, an air gap error signal generator, and an air gap adjustment controller. The load simulation system and the loaded system transmit torque through the force between the magnetic fields in the permanent magnet coupling, achieving non-contact energy transfer. The output load torque can be controlled in real time according to the load simulation requirements.

[0007] The connection method of each component and controller in the load simulation system of this invention is as follows: The loading motor is a servo motor, and its direction of rotation and speed are determined by the loading motor speed controller. The output end of the loading motor is rigidly connected to one side of the permanent magnet rotor (permanent magnet and supporting steel disc) of the permanent magnet coupling, and the conductor rotor (copper disc and supporting steel disc) of the permanent magnet coupling is connected to the rotary device of the loaded system. A first tachometer is mounted on the output shaft of the loading motor. A torque sensor and a second tachometer are mounted on the shaft on one side of the permanent magnet coupling conductor rotor. An air gap displacement sensor is mounted on the permanent magnet coupling. The outputs of the first and second tachometers are both connected to a speed difference signal generator. The outputs of the speed difference signal generator and the speed difference solver are both connected to the loading motor speed controller. The air gap adjustment device on the permanent magnet coupling is connected to a servo motor. The servo motor speed is controlled by the air gap adjustment controller. The output of the second tachometer is also connected to a load / speed converter. The output of the load / speed converter is connected to a speed / air gap converter. The outputs of the air gap displacement sensor and the speed / air gap converter are connected to an air gap error signal generator. The output of the torque sensor is connected to a torque error signal generator. The outputs of the torque error signal generator and the air gap error signal generator are connected to the air gap adjustment controller.

[0008] Furthermore, the working principle of this invention is to adjust the load torque output by the permanent magnet coupling by adjusting the speed difference and air gap between the two ends of the permanent magnet coupling. Then, the load torque is applied as a simulated load to the system being loaded, thus achieving load simulation. The speed difference and air gap are adjusted and controlled separately by their respective controllers and control loops, thereby ensuring that the final output load torque is the desired target value.

[0009] Furthermore, in the control loop for adjusting the speed difference, the speeds measured by the first and second tachometers are the speeds at both ends of the permanent magnet coupling. These speeds are then processed by a speed difference signal generator to obtain a speed difference signal. The torque load command is processed by a speed difference solver to obtain a target speed difference value. The speed difference signal and the target speed difference value are then processed by a load motor speed controller to obtain a load motor speed control signal. Finally, the load motor speed control signal controls the speed and direction of the load motor, thereby further controlling the speed difference at both ends of the permanent magnet coupling. By changing the speed difference between the rotors in the permanent magnet coupling, the output load torque can be changed, thus ultimately achieving the function of adjusting the load torque. The speed difference solver obtains the target speed difference value based on the speed difference-torque characteristics of the permanent magnet coupling.

[0010] Furthermore, for measuring the rotational speed at both ends of the permanent magnet coupling, an angle sensor with a differentiator and filter can be used to generate the speed measurement instead of a tachometer.

[0011] Furthermore, adjusting the load torque solely by controlling the speed difference between the two ends of the permanent magnet coupling via the loading motor will result in some error fluctuations and cannot prevent large overload impacts. The permanent magnet coupling can change the load torque transmitted from the loading motor output to the rotary body of the loaded system by adjusting the air gap between the copper disc and the permanent magnet. A smaller air gap results in a larger transmitted load torque; therefore, the air gap between the copper disc and the permanent magnet can be adjusted using an air gap adjustment device, thereby adjusting the load torque transmitted by the load simulation system to the loaded system.

[0012] Furthermore, in the control loop for adjusting the air gap distance, the air gap adjustment device is electrically controlled via a servo motor. First, the actual load torque measured by the torque sensor and the torque load command are passed through a torque error signal generator to obtain a torque error signal. The torque load command and the speed of the loaded system measured by the second tachometer are passed through a load / speed converter to obtain the target value of the loading motor speed output signal. This signal is then passed through a speed / air gap converter to obtain the target value of the air gap distance signal. The actual air gap distance signal and the target air gap distance signal measured by the air gap distance displacement sensor are passed through an air gap error signal generator to obtain an air gap error signal. The air gap error signal and the torque error signal are then processed through a secondary error adjustment in the air gap adjustment controller to obtain the air gap adjustment signal. This signal controls the speed of the low-power servo motor to drive the air gap adjustment device, thereby changing the air gap distance of the permanent magnet coupling and thus achieving the function of adjusting the load torque. This reduces error fluctuations caused when adjusting the load torque through speed differences.

[0013] Furthermore, when the load torque measured by the torque sensor exceeds the set maximum value, the air gap adjustment controller controls the air gap adjustment device to quickly open the air gap of the permanent magnet coupling, thereby rapidly reducing the load torque and disengaging the load simulation system from the loaded system, thus providing overload protection for the system.

[0014] Furthermore, when the loading motor starts, the permanent magnet coupling adjusts the air gap to its maximum through the air gap adjustment device, allowing the loading motor to start under no-load. Once the loading motor's speed meets the speed difference requirement through the loading controller, the permanent magnet coupling gradually reduces the air gap, ensuring that the load torque is steadily applied to the loaded system, thus achieving a soft start and increasing the system's service life.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] 1) This invention uses a permanent magnet coupling, which has a simple structure, low cost, and is easier to maintain and service.

[0017] 2) The permanent magnet coupling used in this invention realizes non-contact energy transfer, saving energy and reducing consumption.

[0018] 3) This invention can achieve soft start with buffer, which reduces the current surge during the start-up process, reduces the starting energy consumption of the motor, and extends the service life of the system.

[0019] 4) This invention has an overload protection function. When the simulated load on the loaded system is too large, the loaded system and the load simulation system can be disconnected by opening the air gap, thus protecting the loaded system and the loading motor from damage. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of a load simulation system based on a permanent magnet coupling, provided for an embodiment of the present invention.

[0021] The diagram is labeled as follows: 1. Loading motor, 2. First tachometer, 3. Permanent magnet coupling, 4. Torque sensor, 5. Second tachometer, 6. Rotary head, 7. Power source and remaining parts, 8. Servo motor, 9. Air gap adjustment device, 10. Air gap displacement sensor, 11. Speed ​​difference signal generator, 12. Torque error signal generator, 13. Speed ​​difference solver, 14. Loading motor speed controller, 15. Load / speed converter, 16. Speed / air gap converter, 17. Air gap error signal generator, 18. Air gap adjustment controller.

[0022] Figure 2 The block diagram for controlling the speed of the loading motor in the load simulation system provided by the present invention.

[0023] Figure 3 The block diagram of the air gap adjustment control of the load simulation system provided by the present invention. Detailed Implementation

[0024] To better explain and facilitate understanding of the present invention, the following description, using a load simulation system for a horizontal directional drilling rig as an example and in conjunction with the accompanying drawings, will further illustrate the present invention through specific embodiments.

[0025] The primary purpose of load simulation for horizontal directional drilling rigs is to simulate and test different load conditions during rotary loading experiments, in order to evaluate and optimize their performance and stability. Specifically, the load simulation system can simulate torque loads on horizontal directional drilling rigs under various operating conditions, such as load conditions at different speeds and power outputs.

[0026] Please refer to the following example for the load simulation system provided by this invention.

[0027] like Figure 1As shown, an embodiment of the present invention provides a load simulation system based on a permanent magnet coupling, including a loading motor 1, a first tachometer 2, a permanent magnet coupling 3, a torque sensor 4, a second tachometer 5, a servo motor 8, an air gap adjustment device 9, an air gap displacement sensor 10, a speed difference signal generator 11, a torque error signal generator 12, a speed difference solver 13, a loading motor speed controller 14, a load / speed converter 15, a speed / air gap converter 16, an air gap error signal generator 17, and an air gap adjustment controller 18. The loaded system (horizontal directional drilling rig system) includes a rotary head 6, a power source, and the remaining parts 7. The first tachometer 2, the second tachometer 5, the speed difference signal generator 11, the speed difference solver 13, and the motor speed controller 14 belong to the control loop for adjusting the speed difference. The torque sensor 4, the second tachometer 5, the servo motor 8, the air gap adjustment device 9, the air gap distance displacement sensor 10, the torque error signal generator 12, the load / speed converter 15, the speed / air gap converter 16, the air gap error signal generator 17, and the air gap adjustment controller 18 belong to the control loop for adjusting the air gap distance.

[0028] The aforementioned speed difference signal generator 11, torque error signal generator 12, speed difference solver 13, loaded motor speed controller 14, load / speed converter 15, speed / air gap converter 16, air gap error signal generator 17, and air gap adjustment controller 18 all belong to the control loop (software) part. Except for the controllers (14 and 18), the other parts are responsible for generating target and actual signals and inputting them into the controllers (14 and 18). Finally, the controllers (14 and 18) reduce the error between the target and actual signals according to a specific control algorithm, ultimately outputting a control signal that reduces the error. The torque load command is manually given by the host computer (e.g., PC), while the speed difference signal generator 11, torque error signal generator 12, speed difference solver 13, loaded motor speed controller 14, load / speed converter 15, speed / air gap converter 16, air gap error signal generator 17, and air gap adjustment controller 18 are all implemented in the lower-level computer (e.g., PLC / microcontroller).

[0029] The speed difference adjustment and control process at both ends of the permanent magnet coupling 3 is as follows: The speeds measured by the first tachometer 2 and the second tachometer 5 are the speeds of the permanent magnet rotor and the conductor rotor of the permanent magnet coupling 3. These speeds are processed by the speed difference signal generator 11 to obtain a speed difference signal. The torque load command is processed by the speed difference solver 13 to obtain the target speed difference value. The speed difference signal and the target speed difference value are then processed by the load motor speed controller 14 to obtain the speed control signal for the load motor 1. Finally, the speed control signal for the load motor 1 controls the speed and direction of the load motor 1, thereby further controlling the speed difference between the permanent magnet rotor and the conductor rotor. By changing the speed difference between the rotors in the permanent magnet coupling 3, the output load torque can be changed. Therefore, the load torque is ultimately controlled, realizing the function of adjusting the drilling rig load torque. The speed difference solver 13 obtains the target speed difference value based on the speed difference-torque characteristics of the permanent magnet coupling 3.

[0030] The air gap adjustment control process of the permanent magnet coupling 3: The air gap adjustment device 9 is connected to a small-power servo motor 8 for electrical control. First, the actual load torque and torque load command measured by the torque sensor 4 are passed through the torque error signal generator 12 to obtain the torque error signal. The torque load command and the drilling system speed measured by the second tachometer 5 are passed through the load / speed converter 15 to obtain the target value of the load motor speed output signal. Then, this signal is passed through the speed / air gap converter 16 to obtain the target value of the air gap signal. The actual air gap signal and the target value of the air gap signal measured by the air gap displacement sensor 10 are passed through the air gap error signal generator 17 to obtain the air gap error signal. The air gap error signal and the torque error signal are passed through the air gap adjustment controller 18 to obtain the air gap adjustment signal. This signal drives the air gap adjustment device 9 by controlling the speed of the small-power servo motor 8, thereby changing the air gap of the permanent magnet coupling 3, thus realizing the function of adjusting the drilling rig load torque. This can reduce the error fluctuations generated when adjusting the load torque by speed difference.

[0031] The soft-start process of the load simulation system: When the loading motor 1 starts, the permanent magnet coupling 3 adjusts the air gap to the maximum through the air gap adjustment device 9, so that the loading motor starts under no-load 1. After the speed of the loading motor 1 meets the speed difference requirement through the loading motor speed controller 14, the permanent magnet coupling 3 gradually reduces the air gap, so that the load torque is steadily applied to the drilling rig system, realizing the soft start of the load simulation system.

[0032] Overload protection process of load simulation system: When the load torque measured by the torque sensor 4 exceeds the set maximum value, the air gap adjustment controller 18 controls the air gap adjustment device 9 to quickly open the air gap of the permanent magnet coupling 3, thereby quickly reducing the load torque and disengaging the load simulation system from the drilling rig system, thus realizing the overload protection function of the load simulation system.

[0033] The first tachometer 2 and the second tachometer 5, for measuring the rotational speed at both ends of the permanent magnet coupling 3, can be replaced by an angle sensor with a differentiator and a filter to generate the measurement.

[0034] The permanent magnet coupling 3 can be of various structures, such as a single-disc structure, a double-disc structure, a double-cylinder structure, or a double-hybrid structure. Its speed difference-torque characteristic curve varies depending on its structure; therefore, different air gap adjustment devices 9 and air gap adjustment controllers 18 need to be designed according to different structures.

[0035] The air gap adjustment device 9 can be selected from different design models according to specific actual needs.

[0036] The control algorithms in the various controllers mentioned can use the PID algorithm, or they can be replaced with other intelligent control algorithms.

[0037] The load simulation system described above can be used not only for horizontal directional drilling rigs, but also for other systems where the required load torque changes gradually, such as auger pile drivers and rotary drilling rigs.

Claims

1. A load simulation system based on permanent magnet coupling, characterized by: The loading motor (1) is a servo motor, and its direction and speed are determined by the loading motor speed controller (14). The output end of the loading motor (1) is rigidly connected to one side of the permanent magnet rotor of the permanent magnet coupling (3). The conductor rotor side of the permanent magnet coupling (3) is connected to the rotary device (6) of the loaded system. A first tachometer (2) is installed on the shaft at the output end of the loading motor (1). A torque sensor (4) and a second tachometer (5) are installed on the shaft on one side of the conductor rotor of the permanent magnet coupling (3). An air gap displacement sensor (10) is installed on the permanent magnet coupling (3). The first tachometer (2) and the second tachometer (5) are also present. The outputs of both the speed difference signal generator (11) and the speed difference solver (13) are connected to the load motor speed controller (14); the air gap adjustment device (9) on the permanent magnet coupling (3) is connected to the servo motor (8), and the speed of the servo motor (8) is controlled by the air gap adjustment controller (18); the second tachometer (5) The output is also connected to the load / speed converter (15), the output of the load / speed converter (15) is connected to the speed / air gap converter (16), the output of the air gap displacement sensor (10) and the speed / air gap converter (16) is connected to the air gap error signal generator (17), the output of the torque sensor (4) is connected to the torque error signal generator (12), and the output of the torque error signal generator (12) and the air gap error signal generator (17) is connected to the air gap adjustment controller (18). The system adjusts the load torque output by the permanent magnet coupling (3) by adjusting the speed difference and air gap size at both ends of the permanent magnet coupling (3), and then loads the load torque as a simulated load on the loaded system to finally realize load simulation. The speed difference and air gap size are adjusted and controlled by their respective controllers and control loops to ensure that the final output load torque is the required target value.

2. The load simulation system based on permanent magnet coupler according to claim 1, characterized in that: In the control loop for adjusting the speed difference, the speed measured by the first tachometer (2) and the second tachometer (5) is the speed at both ends of the permanent magnet coupling (3). The speed of the two speeds is used to obtain the speed difference signal through the speed difference signal generator (11). The torque load command is used to obtain the speed difference target value through the speed difference solver (13). The speed difference signal and the speed difference target value are then used to obtain the speed control signal of the loading motor (1) through the loading motor speed controller (14). Finally, the speed and direction of the loading motor (1) are controlled by the speed control signal of the loading motor (1), thereby further controlling the speed difference at both ends of the permanent magnet coupling (3). By changing the speed difference between the rotors in the permanent magnet coupling (3), the output load torque is changed, and finally the function of adjusting the load torque is realized.

3. The load simulation system based on a permanent magnet coupling according to claim 2, characterized in that: The speed difference solver (13) obtains the target speed difference value based on the speed difference-torque characteristics of the permanent magnet coupling (3).

4. The load simulation system based on permanent magnet coupler according to claim 2 or 3, characterized in that: For measuring the rotational speed at both ends of the permanent magnet coupling (3), an angle sensor with a differentiator and a filter can be used to generate the speed instead of a tachometer.

5. The load simulation system based on a permanent magnet coupling according to claim 2, characterized in that: In the control loop for adjusting the size of the air gap, the air gap adjustment device (9) is connected to the servo motor (8) to realize electrical control. First, the actual load torque and torque load command measured by the torque sensor (4) are passed through the torque error signal generator (12) to obtain the torque error signal. The torque load command and the speed of the loaded system measured by the second tachometer (5) are passed through the load / speed converter (15) to obtain the target value of the load motor speed output signal. Then, the target value of the load motor speed output signal is passed through the speed / air gap converter (16) to obtain the target value of the air gap signal. The actual air gap signal and the target value of the air gap signal measured by the air gap displacement sensor (10) are passed through the air gap error signal generator (17) to obtain the air gap error signal. The air gap error signal and the torque error signal are passed through the error secondary adjustment in the air gap adjustment controller (18) to obtain the air gap adjustment signal. The air gap adjustment signal drives the air gap adjustment device (9) by controlling the speed of the servo motor (8), thereby changing the size of the air gap of the permanent magnet coupling (3) and thus realizing the function of adjusting the load torque.

6. A load simulation system based on a permanent magnet coupling according to claim 2, 3, or 5, characterized in that: When the loading motor (1) starts, the permanent magnet coupling (3) adjusts the air gap distance to the maximum through the air gap adjustment device (9), so that the loading motor (1) starts under no-load. When the speed of the loading motor (1) meets the speed difference requirement through the loading motor speed controller (14), the permanent magnet coupling (3) gradually reduces the air gap distance, so that the load torque is steadily applied to the loaded system, thus realizing the soft start of the load simulation system.

7. A load simulation system based on a permanent magnet coupling according to claim 2, 3, or 5, characterized in that: When the load torque measured by the torque sensor (4) exceeds the set maximum value, the air gap adjustment controller (18) controls the air gap adjustment device (9) to quickly open the air gap of the permanent magnet coupling (3), thereby quickly reducing the load torque and disengaging the load simulation system from the loaded system, thus realizing the overload protection function of the load simulation system.

8. The load simulation system based on permanent magnet coupler according to claim 2 or 3 or 5, characterized in that: The torque load command is manually given based on the load simulation torque required by the system being loaded.

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