A turntable servo system based on electrical gap elimination

Abstract

The application provides a rotary table servo system based on electrical gap elimination, relates to the technical field of servo control, and a gap elimination torque control unit is matched with a main motor and a slave motor to form a master-slave driving structure through cooperation of a main servo driver and a slave servo driver, drives a main motor pinion and a slave motor pinion to run simultaneously, and makes the shaft system gear of the controlled shaft system in the rotary table system always be subjected to the action of a biasing torque during operation, so that the shaft system gear cannot swing back and forth in the gear gap during starting and reversing, and the rotary table shaft system gap elimination function is completed, the rotary table servo system based on electrical gap elimination improves the static performance and dynamic response capability of the rotary table, has low requirements on the speed reduction transmission structure, and the structure wear and environmental changes do not have influence on the system performance, and the problems of fast stability and accuracy during shaft system positioning are effectively solved.

Description

Technical Field

[0001] This invention relates to the field of servo control technology, and in particular to a turntable servo system based on backlash elimination. Background Technology

[0002] The radar radome test turntable is one of the key pieces of equipment in a certain type of measurement system. During measurement, the turntable's function is to mount the radome under test, precisely change the spatial position of the radome's beam, and adjust the relative position of the antenna and the rotation axis, making its phase center as close as possible to the turntable's rotation axis. Because the radar radome test turntable bears a heavy load, it generally uses an indirect drive mechanism with a large output torque. However, high-torque drive mechanisms often exhibit backlash nonlinearity, affecting the turntable's dynamic performance and steady-state accuracy. Furthermore, due to the non-differentiable nature of backlash, compensation and control are difficult, which may cause system oscillations and prevent accurate positioning.

[0003] To address backlash issues, traditional methods primarily employ mechanical backlash elimination techniques, with double-gear reverse preload being a common approach. This method involves applying opposing preload forces to a rack or other transmission component using two gears, ensuring a tight fit between the gears and the transmission component, thereby eliminating backlash. However, this mechanical backlash elimination method has several limitations. While reverse preload on dual gears can reduce backlash to some extent, it cannot completely eliminate it, especially after long-term use. Due to gear wear and other factors, the backlash gradually increases, leading to a decrease in repeatability. In some radar applications with extremely high precision requirements, such as military reconnaissance radar, even tiny positioning errors can have serious consequences, and mechanical backlash elimination methods are insufficient to meet these high-precision requirements. Mechanical backlash elimination methods also lack control flexibility. Once the mechanical structure is installed and debugged, its backlash elimination effect and method are essentially fixed, making it difficult to adjust flexibly according to different working conditions and mission requirements. Under different ambient temperatures and load conditions, the size of the backlash may change, and mechanical backlash elimination methods cannot adjust the backlash elimination force in real time to adapt to these changes. Mechanical backlash elimination typically requires high-precision gears and complex preload mechanisms, which not only increases the system's manufacturing cost but also necessitates greater investment of manpower and resources for subsequent maintenance and upkeep. Regularly checking and adjusting the preload, replacing worn gears, and other tasks all increase the system's operating costs and maintenance complexity. In conclusion, traditional mechanical backlash elimination methods have significant shortcomings in addressing the backlash problem in radar turntable servo systems, urgently requiring a more effective backlash elimination technology to improve system performance.

[0004] Traditional mechanical backlash elimination methods are limited by the precision of the mechanical structure itself and the wear and tear after long-term use, making it difficult to achieve high-precision repeatability. Dual-motor electrical backlash elimination technology, through precise electrical control, can adjust the offset torque in real time, ensuring that the transmission components maintain close contact under different operating conditions, effectively avoiding the impact of backlash on positioning accuracy. Related experimental data shows that radar turntable servo systems using electrical backlash elimination technology can improve repeatability several times compared to traditional mechanical backlash elimination systems, achieving accuracy levels of ±0.01mm or even higher. This is of paramount importance for radar applications requiring high-precision tracking and measurement. When tracking high-precision targets such as satellites, high repeatability ensures that the radar always points accurately at the target, providing more precise target position information.

[0005] In the backlash elimination system, the control method of the two motors is highly flexible. On the one hand, when backlash needs to be eliminated, the two motors can drive in opposite directions according to the target strategy, eliminating backlash through the generated bias torque; on the other hand, when the system needs to increase the driving torque, the two motors can drive in the same direction, jointly providing greater power to the system. This flexible control method allows the system to quickly adjust its operating mode according to different tasks and operating conditions, greatly improving the system's adaptability and reliability. When the radar tracks targets with different speeds and maneuvers, the system can flexibly adjust the motor drive mode according to the target's motion state, ensuring that the radar antenna can track the target quickly and accurately.

[0006] By employing electrical backlash elimination technology, high-precision reduction mechanisms with mechanical backlash elimination functions can be replaced with ordinary-precision reduction gearboxes. Ordinary-precision reduction gearboxes are relatively inexpensive and have a simpler manufacturing process, thus reducing the overall system manufacturing cost. Unlike mechanical backlash elimination systems, electrical backlash elimination systems do not require periodic adjustments to the mechanical backlash elimination mechanism, reducing the workload and cost of later maintenance. Statistics show that radar turntable servo systems using electrical backlash elimination technology can reduce manufacturing costs by 20%-30% compared to traditional mechanical backlash elimination systems, and also significantly reduce later maintenance costs, making electrical backlash elimination technology more cost-effective in practical applications.

[0007] Based on this, the present invention provides a turntable servo system based on electrical backlash elimination. Summary of the Invention

[0008] The purpose of this invention is to provide a turntable servo system based on electrical backlash elimination to solve the problems mentioned in the background art.

[0009] To address the aforementioned technical problems, this invention provides a turntable servo system based on electrical backlash elimination, comprising a backlash elimination torque control unit, a main servo driver, a main motor, a main motor pinion, a slave servo driver, a slave motor, a slave motor pinion, and a shaft system large gear. The backlash elimination torque control unit, through the cooperation of the main servo driver and the slave servo driver, forms a master-slave drive structure with the main motor and the slave motor, driving the main motor pinion and the slave motor pinion to run simultaneously. This ensures that the shaft system large gear of the controlled shaft system in the turntable system is always subjected to an offset torque during operation, preventing it from swinging back and forth in the gear gap during startup and reversal, thereby completing the backlash elimination function of the turntable shaft system.

[0010] Furthermore, the backlash-free torque control unit is a motion controller that communicates with the main servo driver via an EtherCAT interface and sends control commands.

[0011] Furthermore, the main servo driver, the main motor, and the main motor pinion form a main motor pinion transmission system. The main servo driver receives control signals sent by the backlash elimination torque control unit through the EtherCAT interface, and then converts them into corresponding motion commands to drive the main motor to rotate, thereby driving the main motor pinion to rotate and generating a positive driving torque.

[0012] Furthermore, the slave servo driver, the slave motor, and the slave motor pinion form a slave motor pinion transmission system. The slave servo driver receives the control signal sent by the master servo driver through the EtherCAT interface, and then converts it into a corresponding motion command to drive the slave motor to rotate, thereby driving the slave motor pinion to rotate and generating a reverse driving torque.

[0013] Furthermore, the main motor and the slave motor have the same model, and the pinion gear of the main motor and the pinion gear of the slave motor have the same size and specifications.

[0014] Furthermore, during operation, the large gear of the shaft system is always subjected to the bias torque formed by the small gear of the main motor and the small gear of the driven motor, and cannot swing back and forth in the gear gap during startup and reversal.

[0015] Furthermore, in a specific implementation of the present invention, the backlash elimination torque control unit 1, the main servo driver 2, and the slave servo driver 5 are fixedly installed in the control cabinet of the turntable servo system. The main motor 3, the main motor pinion 4, the slave motor 6, and the slave motor pinion 7 are fixedly installed in the turntable orientation axis system of the turntable servo system. The backlash elimination torque control unit 1 receives the angle signal of the axis system angle feedback 9 through the angle measurement signal cable, generates corresponding control commands, and sends them to the main servo driver 2 through the EtherCAT communication cable. After receiving the control commands, the main servo driver 2 sends the opposite control commands to the slave servo driver 5 through the EtherCAT communication cable. The main servo driver 2 and the slave servo driver 5 send PWM control signals to the main motor 3 and the slave motor 6 through the motor cable, thereby driving the main motor pinion 4 and the slave motor pinion 7 to rotate, generating two opposite driving torques, forming a variable bias torque, so that the large gear of the axis system in the turntable servo system cannot swing back and forth in the gear backlash, thereby achieving the backlash elimination effect. The turntable servo system based on electrical backlash elimination achieves the purpose of eliminating gear backlash by using two identical servo transmission mechanisms in conjunction with servo drivers and the backlash elimination torque control unit.

[0016] The beneficial effects of this invention compared with the prior art are: (1) This invention includes a backlash-free torque control unit, a main servo driver, a main motor, a main motor pinion, a slave servo driver, a slave motor, a slave motor pinion, and a shaft gear. Its control structure is simple, easy to use, and highly versatile. The turntable servo system based on electrical backlash-free technology improves the static performance and dynamic response capability of the turntable. It has low requirements for the deceleration transmission structure. The wear of the structure and changes in the environment will not affect the system performance. It effectively solves the problem of fast, stable and accurate shaft positioning. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the principle framework of the present invention.

[0018] Figure 2 This is a schematic diagram of the overall structure of the present invention.

[0019] Figure 3 This is a schematic diagram of the assembly structure of the main motor pinion and the slave motor pinion of the present invention.

[0020] Figure 4 This is a schematic diagram of the overall structure of the main servo driver of the present invention.

[0021] Reference numerals in the attached diagram: 1-Backlash elimination torque control unit; 2-Main servo driver; 3-Main motor; 4-Main motor pinion; 5-Slave servo driver; 6-Slave motor; 7-Slave motor pinion; 8-Shaft gear; 9-Shaft angle feedback. Detailed Implementation

[0022] The technical solution provided by the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0023] like Figures 1-4 As shown, a turntable servo system based on electrical backlash elimination includes a backlash elimination torque control unit 1, a master servo driver 2, a master motor 3, a master motor pinion 4, a slave servo driver 5, a slave motor 6, a slave motor pinion 7, and a shaft system large gear 8. The backlash elimination torque control unit 1, through the cooperation of the master servo driver 2 and the slave servo driver 5, forms a master-slave drive structure with the master motor 3 and the slave motor 6, driving the master motor pinion 4 and the slave motor pinion 7 to run simultaneously. This ensures that the shaft system large gear 8 of the controlled shaft system in the turntable system is always subjected to an offset torque during operation, preventing it from swinging back and forth in the gear gap during startup and reversal, thereby completing the backlash elimination function of the turntable shaft system.

[0024] like Figures 1-4 As shown, after receiving the angle signal from the shaft angle feedback 9, the backlash elimination torque control unit 1 generates a corresponding control command and sends it to the main servo driver 2 through the EtherCAT interface.

[0025] like Figures 1-4 As shown, the main servo driver 2, the main motor 3, and the main motor pinion 4 form a main motor pinion transmission system. The main servo driver 2 receives the control signal sent by the backlash elimination torque control unit 1 through the EtherCAT interface, and then converts it into a corresponding motion command to drive the main motor 3 to rotate, thereby driving the main motor pinion 4 to rotate and generating a positive driving torque.

[0026] like Figures 1-4 As shown, the slave servo driver 5, the slave motor 6, and the slave motor pinion 7 form a slave motor pinion transmission system. The slave servo driver 5 receives the control signal sent by the master servo driver through the EtherCAT interface, and then converts it into a corresponding motion command to drive the slave motor 6 to rotate, thereby driving the slave motor pinion 7 to rotate and generating a reverse driving torque.

[0027] like Figures 1-4 As shown, the large gear 8 of the shaft system is always subjected to the bias torque formed by the small gear 6 of the main motor and the small gear 7 of the driven motor during operation. It cannot swing back and forth in the gear gap during startup and reversal, thereby achieving the effect of eliminating backlash and realizing the rapid and accurate positioning of the turntable servo system.

[0028] Working Principle: In the specific implementation of this invention, the backlash elimination torque control unit 1, the main servo driver 2, and the slave servo driver 5 are fixedly installed in the control cabinet of the turntable servo system. The main motor 3, the main motor pinion 4, the slave motor 6, and the slave motor pinion 7 are fixedly installed in the turntable orientation axis system of the turntable servo system. The backlash elimination torque control unit 1 receives the angle signal of the axis system angle feedback 9 through the angle measurement signal cable, generates corresponding control commands, and sends them to the main servo driver 2 through the EtherCAT communication cable. After receiving the control commands, the main servo driver 2 sends the opposite control commands to the slave servo driver 5 through the EtherCAT communication cable. The main servo driver 2 and the slave servo driver 5 send PWM control signals to the main motor 3 and the slave motor 6 through the motor cable, thereby driving the main motor pinion 4 and the slave motor pinion 7 to rotate, generating two opposite driving torques, forming a variable bias torque, so that the large gear of the axis system in the turntable servo system cannot swing back and forth in the gear backlash, thereby achieving the backlash elimination effect. The turntable servo system based on electrical backlash elimination achieves the purpose of eliminating gear backlash by using two identical servo transmission mechanisms in conjunction with servo drivers and the backlash elimination torque control unit.

Claims

1. A turntable servo system based on electrical backlash elimination, comprising a backlash elimination torque control unit (1), a main servo driver (2), a main motor (3), a main motor pinion (4), a slave servo driver (5), a slave motor (6), a slave motor pinion (7), a shaft system gear (8), and shaft system angle feedback (9), characterized in that, The backlash elimination torque control unit (1) works with the master servo driver (2) and the slave servo driver (5) to form a master-slave drive structure with the master motor (3) and the slave motor (6), driving the master motor pinion (4) and the slave motor pinion (7) to run simultaneously, so that the shaft system large gear (8) of the controlled shaft system in the turntable system is always subjected to the bias torque during operation, thereby completing the backlash elimination function of the turntable shaft system.

2. The turntable servo system based on backlash elimination according to claim 1, characterized in that, The backlash elimination torque control unit (1) is a motion controller that connects to and communicates with the main servo driver (2) via an EtherCAT interface and sends control commands.

3. The rotary table servo system based on backlash elimination according to claim 1, characterized in that, The backlash elimination torque control unit (1) is connected to the shaft angle feedback (9) via an angle measurement signal cable to monitor the angle of the rotating shaft.

4. A turntable servo system based on electrical backlash elimination according to claim 1, characterized in that, The main servo driver (2), together with the main motor (3) and the main motor pinion (4), forms the main motor pinion transmission system. The main servo driver (2) receives the control signal sent by the backlash elimination torque control unit (1) through the EtherCAT interface, and then converts it into a corresponding motion command to drive the main motor (3) to rotate, thereby driving the main motor pinion (4) to rotate and generating a positive driving torque.

5. A turntable servo system based on electrical backlash elimination according to claim 1, characterized in that, The slave servo driver (5), the slave motor (6), and the slave motor pinion (7) form a slave motor pinion transmission system. The slave servo driver (5) receives the control signal sent by the master servo driver (2) through the EtherCAT interface, and then converts it into a corresponding motion command to drive the slave motor (6) to rotate, thereby driving the slave motor pinion (7) to rotate and generating a reverse driving torque.

6. A turntable servo system based on electrical backlash elimination according to claim 1, characterized in that, The main motor (3) and the slave motor (6) are of the same model, and the main motor pinion (4) and the slave motor pinion (7) are of the same size and specifications.

7. A turntable servo system based on backlash elimination according to claim 1, characterized in that, During operation, the large gear (8) of the shaft system is always subjected to the bias torque formed by the main motor pinion (4) and the driven motor pinion (7), and cannot swing back and forth in the gear gap during startup and reversal.

Images