Four-motor anti-backlash system and method for large antenna array inversion control

Abstract

The application discloses a four-motor anti-backlash system and method for large antenna array surface overturning control, and belongs to the technical field of servo transmission. The system comprises an antenna array surface, an antenna overturning mechanism, a speed reducer, servo motors, servo drivers, a servo controller and a pitch angle measuring device. The antenna array surface pitch shaft system has a pair of half toothed rings at both ends, and each half toothed ring is driven by two servo motors. The half toothed rings are connected with the servo motors through transmission gears and the speed reducer. The servo controller controls the four servo motors through four servo drivers. The servo controller obtains the angle values of the antenna array surface at both ends through the pitch angle measuring device. A control scheme suitable for the system is provided. In order to realize the system overturning positioning function, the control scheme is based on a position loop, a speed loop and a current loop three-loop structure, is suitable for large antenna array surface overturning control, and has higher positioning accuracy and better low-speed stability compared with a traditional position synchronization or speed synchronization scheme.

Description

Technical Field

[0001] This invention relates to the field of servo drive technology, specifically to a four-motor backlash elimination system and method for large antenna array flipping control. Background Technology

[0002] Currently, fixed-platform antenna arrays mostly use two torque input sources distributed at both ends of the elevation axis to perform the flipping action. For motor input sources, small and medium-sized antenna arrays are beginning to adopt a dual-motor backlash elimination scheme, with two motors located on both sides of the antenna axis. In order to maintain backlash elimination, there is an offset torque in the output torque of the two motors during the low torque stage to clamp the large transmission gear. Considering that the antenna array will deform under actual force, it is not possible to achieve complete left-right synchronization.

[0003] If a large antenna array employs the aforementioned dual-motor backlash elimination scheme, the deformation caused by stress can alter the array's flatness, affecting observation accuracy. Prolonged deformation may also pose safety risks. Therefore, current large antenna array flipping operations often utilize position synchronization or speed synchronization schemes. However, backlash exists during transmission, leading to positioning errors and consequently affecting observation accuracy. Furthermore, when the antenna array passes overhead, the change in load torque direction and existing backlash can alter the meshing surface of the transmission gears, causing antenna array vibration and impacting low-speed stability of the flipping operation.

[0004] In view of the above-mentioned defects, the inventors of this invention have finally obtained this invention after a long period of research and practice. Summary of the Invention

[0005] The technical problem to be solved by this invention is: how to solve the problem of tooth gaps in the transmission process of large antenna array flipping action, which affects the antenna flipping positioning accuracy and low-speed stability, and provides a four-motor gap elimination system and method for large antenna array flipping control.

[0006] A four-motor backlash elimination system for large antenna array flipping control includes an antenna array, an antenna flipping mechanism, a servo drive mechanism, and an elevation angle measuring device. The antenna flipping mechanism is connected to the antenna array, and the center of gravity of the antenna flipping mechanism is located on the same horizontal line as the center of gravity of the antenna array. The elevation angle measuring device is arranged on both sides of the antenna array along the transverse axis of the antenna array. The elevation angle measuring device transmits an angle signal to the servo drive mechanism, and the servo drive mechanism drives the antenna flipping mechanism to flip.

[0007] The antenna flipping mechanism includes two half-tooth rings and four transmission gears. The two half-tooth rings are vertically arranged on the back of the antenna array, and both ends of the two half-tooth rings are connected to the antenna array. The two transmission gears are meshed with one of the half-tooth rings, and the other two transmission gears are meshed with the other half-tooth ring. The four transmission gears are all connected to the corresponding servo drive mechanism.

[0008] Furthermore, the antenna flipping mechanism also includes multiple connecting rods, and the two half-tooth rings are connected by multiple connecting rods.

[0009] Furthermore, both of the two semi-toothed rings are distributed along the longitudinal axis of the antenna array, with one end of each semi-toothed ring connected to the upper surface of the antenna array and the other end of each semi-toothed ring connected to the lower surface of the antenna array.

[0010] Furthermore, the servo drive mechanism includes a servo motor, a servo driver, and a servo controller. The pitch angle measuring device transmits angle signals to the servo controller, the servo controller transmits control signals to the servo driver, the servo driver is connected to the servo motor, and the output shaft of the servo motor is connected to a transmission gear.

[0011] Furthermore, the backlash elimination system also includes a speed reducer, and the output shaft of the servo motor is connected to the transmission gear through the speed reducer.

[0012] Furthermore, the servo motor is divided into a master group and a slave group. The master group includes a master motor and a master-auxiliary motor, and the slave group includes a slave motor and a slave-auxiliary motor. One end of the master motor and the master-auxiliary motor are respectively connected to the corresponding servo driver, and the other end of the master motor and the master-auxiliary motor are respectively connected to two transmission gears through a reducer. One end of the slave motor and the slave-auxiliary motor are respectively connected to the corresponding servo driver, and the other end of the master motor and the master-auxiliary motor are respectively connected to two other transmission gears through a reducer.

[0013] A method for eliminating backlash in the aforementioned four-motor backlash elimination system for large antenna array flipping control includes the following steps:

[0014] S1: Calculate the angle difference between the pitch angle measured by the current pitch angle measuring device and the target angle.

[0015] The servo controller receives the target angle θ;

[0016] Read the pitch angle value measured by the pitch angle measuring device: the pitch angle value of the main unit measured by the pitch angle measuring device is defined as θ1, and the pitch angle value of the slave unit is defined as θ2;

[0017] Calculate the angle difference Δθ1 = θ - θ1 of the main unit and the angle difference Δθ2 = θ - θ2 of the secondary unit;

[0018] S2: Obtain the set speeds of the main unit and the slave unit based on the angle difference.

[0019] Determine whether the master unit and slave unit meet the positioning accuracy requirements. If not, calculate the master unit set speed Vset1 and slave unit set speed Vset2 based on the position loop PID algorithm.

[0020] If the positioning accuracy requirement is met, proceed to step S6;

[0021] S3: Calculate the output speed of the master unit and slave unit.

[0022] The maximum acceleration a that limits antenna array flipping max ;

[0023] The cycle time is defined as Δt;

[0024] The reduction ratio of the motor reducer is n;

[0025] Calculate the antenna array velocity increment ΔV = a max ×Δt×n;

[0026] When the PLC processes the nth cycle, the main unit outputs the rotational speed.

[0027] Output speed of the unit

[0028] S4: Calculate the set current of the master unit and slave unit.

[0029] The set current Iset1 of the main unit and the set current Iset2 of the slave unit are calculated based on the speed loop PID.

[0030] Collect the motor speed feedback Vrec1 from the main unit and the motor speed feedback Vrec2 from the slave unit;

[0031] Calculate the speed difference ΔV1 = Vout1 - Vrec1 of the main generator set and the speed difference ΔV2 = Vout2 - Vrec2 of the slave generator set;

[0032] When the PLC processes the nth cycle:

[0033]

[0034]

[0035] S5: Calculate the output current and output voltage of each motor driver.

[0036] The bias current i1 of the master unit and the bias current i2 of the slave unit are given based on experience;

[0037] Based on the master unit set current Iset1 and slave unit set current Iset2 in S4, the master output current Iout1 = Iset1-i1, the master-slave output current Iout2 = Iset1+i1, the slave output current Iout3 = Iset2-i2 and the slave-slave output current Iout4 = Iset2+i2 are given respectively.

[0038] The internal drive board of the servo driver calculates the output voltage based on the output current of the master unit and the slave unit, and drives the servo motor to output torque.

[0039] S6: Determine whether the difference between the current system angle and the target angle meets the accuracy requirements.

[0040] When -ε < Δθ1 < ε and -ε < Δθ2 < ε, it is determined that the difference between the current angle of the system and the target angle meets the positioning accuracy requirements.

[0041] Set the main unit set speed Vset1 = 0, the slave unit set speed Vset2 = 0, and return to step S3;

[0042] Wait for the main motor and slave motor to decelerate to stop. The main motor output current Iout1 = -i1, the main auxiliary output current Iout2 = i1, the slave output current Iout3 = -i2, and the slave auxiliary output current Iout4 = i2. The flipping and positioning process ends.

[0043] If the above conditions are not met, return to step S1.

[0044] Furthermore, in step S2, the set speed Vset1 of the main unit and the set speed Vset2 of the slave unit are calculated, specifically including the following steps:

[0045] S21: When the PLC processes the nth cycle, if -ε < Δθ1 < ε, it is determined that the positioning accuracy requirement is met on the main unit side, and the main unit sets the rotation speed Vset1. n =0; If the positioning accuracy requirements are not met on the main unit side, the main unit's set speed Vset1 n =Vset1 n-1 +K p ×(Δθ1 n -Δθ1 n-1 )+K i ×Δθ1 n +K d ×(Δθ1 n -Δθ1 n-1 ×2+Δθ1 n-2 );

[0046] S22: When -ε < Δθ2 < ε, determine that the positioning accuracy requirement is met on the generator side, and set the generator speed Vset2. n=0; If the positioning accuracy requirement is not met from the unit side, the unit set speed Vset2 is used. n =Vset2 n-1 +K p ×(Δθ2 n -Δθ2 n-1 )+K i ×Δθ2 n +K d ×(Δθ2 n -Δθ2 n-1 ×2+Δθ2 n-2 ).

[0047] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0048] 1. The antenna array rotating shaft of the present invention has a pair of half-tooth rings at both ends. Each half-tooth ring is driven by two servo motors. The half-tooth rings are connected to the servo motors through transmission gears, couplings and reducers. The servo controller controls four servo motors through four servo drivers. The servo controller obtains the angle values ​​of the antenna array at both ends through the elevation angle measuring device installed on the rotating shaft, ensuring the flatness of the antenna array and improving the observation accuracy.

[0049] 2. This invention is based on a typical three-loop structure of position loop, speed loop, and current loop. The position loop ensures the synchronous function of the movement at both ends of the rotating shaft, while the speed loop and current loop ensure the backlash elimination function between the single-sided half gear ring and the transmission gears driven by the two motors, thus solving the problems of low positioning accuracy and poor low-speed stability in the large antenna array flipping control. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the four-motor backlash elimination system in an embodiment of the present invention;

[0051] Figure 2 This is a schematic diagram of the backlash elimination principle of the four motors in an embodiment of the present invention;

[0052] Figure 3 This is a flowchart illustrating the flip control scheme in an embodiment of the present invention;

[0053] Figure 4 This is a graph showing the change in current of each motor during the flipping action in an embodiment of the present invention;

[0054] Figure 5 This is a graph showing the angle values ​​of the pitch measuring device and the target angle during the flipping action in an embodiment of the present invention.

[0055] The numbers in the attached diagram represent:

[0056] 1-Antenna array; 2-Main unit side angle measuring device; 3-Slave unit side angle measuring device; 4-Half gear ring; 5-Transmission gear; 6-Connecting rod; 7-Main motor; 8-Main and auxiliary motors; 9-Slave motor; 10-Slave and auxiliary motors; 11-Reducer. Detailed Implementation

[0057] The embodiments of the present invention are described in detail below. These embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments.

[0058] Example 1

[0059] like Figure 1 As shown, Figure 1 This is a schematic diagram of the four-motor backlash elimination system in this embodiment; it includes an antenna array 1, an antenna flipping mechanism, and a servo motor. The antenna flipping mechanism is connected to the antenna array 1, and the center of gravity of the antenna flipping mechanism is on the same horizontal line as the center of gravity of the antenna array 1. The servo motor drives the antenna flipping mechanism to flip.

[0060] The antenna flipping mechanism includes two half-tooth rings 3 and four transmission gears 4. The two half-tooth rings 3 are respectively vertically connected to the antenna array 1. Two of the transmission gears 4 are meshed with one half-tooth ring 3, and the other two transmission gears 4 are meshed with the other half-tooth ring 3. The four transmission gears 4 are all located on the lower side of the corresponding half-tooth ring 3. The four transmission gears 4 are all connected to the output end of the servo drive mechanism through a reducer 11.

[0061] The antenna flipping mechanism also includes multiple connecting rods 5. The two semi-toothed rings 3 are connected by multiple connecting rods 5, making the antenna flipping mechanism more stable. The two semi-toothed rings 3 are distributed along the longitudinal axis of the antenna array 1. The upper ends of the two semi-toothed rings 3 are respectively connected to the upper end face of the antenna array 1, and the lower ends of the two semi-toothed rings 3 are respectively connected to the lower end face of the antenna array 1.

[0062] Two transmission gears 4 are distributed in a front-to-back manner on the corresponding half gear ring 3. Each transmission gear 4 is connected to a corresponding reducer 11. The servo motor is connected to the reducer 11 and drives the transmission gear 4 to move through the reducer 11.

[0063] like Figure 2 As shown, Figure 2This is a schematic diagram of the backlash elimination principle of the four motors in this embodiment; the servo drive mechanism includes a servo motor, a servo driver and a servo controller. The servo motor is connected to the servo driver through a power cable and a feedback signal cable. The servo driver and the servo controller are connected through a cable. The controller transmits control signals to the servo driver. The servo motor, as an actuator, is controlled by the servo driver and outputs torque to drive the reducer 11 to move.

[0064] like Figure 1 As shown, Figure 1 The position along the dotted line in the diagram represents the location of the antenna elevation axis. The elevation angle measuring device is located at both ends of the antenna elevation axis and is coaxially mounted with the antenna elevation axis. The elevation angle measuring device transmits angle signals to the servo drive mechanism. The elevation angle measuring device is connected to the controller via an SSI signal. As a sensing component, the elevation angle measuring device measures the angle of the antenna array 1 and periodically feeds it back to the servo controller.

[0065] Furthermore, in an ideal state, the geometric center of antenna array 1 coincides with its centroid.

[0066] Furthermore, the gears of the antenna flipping mechanism at both ends of the antenna elevation axis are of the same size.

[0067] Furthermore, the four sets of servo drives, servo motors, and reducers 11 are identical in model and size.

[0068] Furthermore, the two elevation angle measuring devices are the host-side angle measuring device 2 and the slave-side angle measuring device 3, respectively. The host-side angle measuring device 2 and the slave-side angle measuring device 3 are of the same model and are located at both ends of the antenna elevation axis system. They are either coaxially or non-coaxially installed with the antenna elevation axis system, but they can all be processed in the same way to obtain the elevation angle value of the antenna array 1.

[0069] The servo controller serves as the control component. It is connected to the pitch angle measuring device, receives control commands, detects the status of the pitch angle measuring device, and outputs control signals to the servo driver.

[0070] like Figure 1As shown, the two transmission gears 4 on the two half-gear rings 3 are each connected to a corresponding servo motor via a reducer 11. The servo motors driving the two transmission gears 4 on the left side of the antenna array 1 constitute the main unit, with the two servo motors in the main unit being the main motor 6 and the main-auxiliary motor 7. The servo motors driving the two transmission gears 4 on the right side of the antenna array 1 constitute the slave unit, with the two servo motors in the slave unit being the slave motor 8 and the slave-auxiliary motor 9. The main motor 6 is connected to the reducer 11 near the bottom of the corresponding half-gear ring 3, while the main-auxiliary motor 7 is located on the reducer 11 away from the bottom of the corresponding half-gear ring 3. The slave motor 8 is located on the reducer 11 near the bottom of the corresponding half-gear ring 3, and the slave-auxiliary motor 9 is located on the reducer 11 away from the bottom of the corresponding half-gear ring 3. The main unit and the slave unit together complete the synchronous control of the flipping of the antenna array 1. The main motor 6 and the main-auxiliary motor 7 form a backlash elimination control on the main unit side, and the slave motor 8 and the slave-auxiliary motor 9 form a backlash elimination control on the slave unit side.

[0071] The servo motors are controlled and driven by servo drivers. The main motor 6 is connected to the host driver, the main auxiliary motor 7 is connected to the main auxiliary driver, the slave motor 8 is connected to the slave driver, and the slave auxiliary motor 9 is connected to the slave auxiliary driver. The host driver, main auxiliary driver, slave driver, and slave auxiliary driver are all connected to the servo controller.

[0072] The servo driver, as a driving component, outputs voltage to the servo motor to drive its movement.

[0073] The servo motor drives the transmission gear 4 through the reducer 11. The servo motor drives the reducer 11, which in turn drives the transmission gear 4 and the half-gear ring 3 to rotate, thereby realizing the antenna flipping action.

[0074] Example 2

[0075] like Figure 3 As shown, this embodiment provides a method for controlling the flipping of antenna array 1 using the system, the steps of which are as follows:

[0076] S1: Calculate the angle difference between the pitch angle measured by the current pitch angle measuring device and the target angle.

[0077] The servo controller receives the target angle θ;

[0078] Read the pitch angle value measured by the pitch angle measuring device: the pitch angle value of the main unit measured by the pitch angle measuring device is defined as θ1, and the pitch angle value of the slave unit is defined as θ2;

[0079] Calculate the angle difference Δθ1 = θ - θ1 of the main unit and the angle difference Δθ2 = θ - θ2 of the secondary unit;

[0080] S2: Obtain the set speeds of the main unit and the slave unit based on the angle difference.

[0081] Determine whether the master unit and slave unit meet the positioning accuracy requirements. If not, calculate the master unit set speed Vset1 and slave unit set speed Vset2 based on the position loop PID algorithm.

[0082] If the positioning accuracy requirement is met, proceed to step S6;

[0083] When the PLC processes the nth cycle, if -ε < Δθ1 < ε, it determines that the positioning accuracy requirement is met on the main unit side, and sets the main unit speed Vset1. n =0; If the positioning accuracy requirements are not met on the main unit side, the main unit's set speed Vset1 n =Vset1 n-1 +K p ×(Δθ1 n -Δθ1 n-1 )+K i ×Δθ1 n +K d ×(Δθ1 n -Δθ1 n-1 ×2+Δθ1 n-2 );

[0084] When -ε < Δθ2 < ε, it is determined that the positioning accuracy requirement is met from the generator side, and the generator set speed Vset2 is used. n =0; If the positioning accuracy requirement is not met from the unit side, the unit set speed Vset2 is used. n =Vset2 n-1 +K p ×(Δθ2 n -Δθ2 n-1 )+K i ×Δθ2 n +K d ×(Δθ2 n -Δθ2 n-1 ×2+Δθ2 n-2 ).

[0085] In summary, the main unit's set speed Vset1 and the slave unit's set speed Vset2 are:

[0086]

[0087]

[0088] S3: Calculate the output speed of the master unit and slave unit.

[0089] The maximum acceleration a that limits the flipping of antenna array 1 max ;

[0090] The cycle time is defined as Δt;

[0091] The reduction ratio of reducer 11 is n;

[0092] Calculate the velocity increment ΔV = a of antenna array 1 max ×Δt×n;

[0093] When the PLC processes the nth cycle, the main unit outputs the rotational speed.

[0094] Output speed of the unit

[0095] S4: Calculate the set current of the master unit and slave unit.

[0096] The main unit set current Iset1 and the slave unit set current Iset2 are calculated based on the speed loop PID; the motor speed feedback Vrec1 and Vrec2 are collected, and the speed difference ΔV1 = Vout1 - Vrec1 and ΔV2 = Vout2 - Vrec2 are calculated.

[0097] When the PLC processes the nth cycle:

[0098]

[0099]

[0100] The PID parameters here are not the same set of data as in step S2.

[0101] S5: Calculate the output current and output voltage of each motor driver.

[0102] Based on experience, the bias current i1 of the master unit and the bias current i2 of the slave unit are given.

[0103] Based on the master set current Iset1 and slave set current Iset2 in step S4, the master output current Iout1 = Iset1-i1, the master-slave output current Iout2 = Iset1+i1, the slave output current Iout3 = Iset2-i2, and the slave-slave output current Iout4 = Iset2+i2 are given respectively.

[0104] The internal drive board of the servo driver calculates the output voltage based on the output current of the master unit and the slave unit, and drives the servo motor to output torque.

[0105] S6: Determine whether the difference between the current system angle and the target angle meets the accuracy requirements.

[0106] When -ε < Δθ1 < ε and -ε < Δθ2 < ε, it is determined that the difference between the current angle of the system and the target angle meets the positioning accuracy requirements.

[0107] Set the main unit set speed Vset1 = 0, the slave unit set speed Vset2 = 0, and return to step S3;

[0108] Wait for the main motor 6 and slave motor 8 to decelerate to a stop. The main motor output current Iout1 = -i1, the main auxiliary output current Iout2 = i1, the slave output current Iout3 = -i2, and the slave auxiliary output current Iout4 = i2. The flipping and positioning process ends.

[0109] If the above conditions are not met, return to step S1.

[0110] The specific working principle is as follows: The servo controller uses the input target angle as the position loop input of the master unit and the slave unit, and uses the feedback angle of the angle measuring devices at both ends as the position loop feedback. It outputs the control speed to the servo driver to control the speed of the master unit and the slave unit, thereby achieving the purpose of controlling the position loop.

[0111] Two servo drives on one side use the control speed of the servo controller as the input of the speed loop and the rotational speed of the servo motor as the feedback of the speed loop. Based on the linear relationship between the output torque and current of the servo motor, the current i0 required for the two servo motors to maintain their speed is given.

[0112] To achieve the backlash elimination function, based on the current i0 required to maintain the speed of the servo motor, two bias currents i′ in opposite directions are applied to the two servo motors to clamp the transmission gears 4 driven by the two servo motors with the corresponding half-gear rings 3 to eliminate backlash. The adjustment control quantities (i0-i′) and (i0+i′) output by the speed loop are read by the drive processing circuit, and the given control voltages of the two current loops are calculated.

[0113] In the backlash elimination mode of this example, when the system is in closed-loop backlash elimination working state, there will never be a situation where the output torque of the two servo motors on one side is zero at the same time. At any time, at least one of the two servo motors will apply a non-zero torque to the half gear ring 3. Under the action of this torque, there is no movement gap between the half gear ring 3 and the transmission gear 4.

[0114] Example 3

[0115] S1: Read position loop input: Calculate the angle difference between the pitch angle measured by the current pitch angle measuring device and the target angle.

[0116] The servo controller receives a target angle θ = 30°;

[0117] Read the pitch angle value measured by the pitch angle measuring device: the pitch angle value of the main unit measured by the pitch angle measuring device is defined as θ1, and the pitch angle value of the slave unit is defined as θ2;

[0118] Calculate the angle difference Δθ1 = θ - θ1 of the main unit and the angle difference Δθ2 = θ - θ2 of the secondary unit;

[0119] S2: Calculate the position loop output: Calculate the set speed of the master unit and slave unit respectively based on the angle difference;

[0120] Based on the set positioning accuracy 2ε, the set rotational speed is calculated.

[0121] When the PLC processes the nth cycle, if -ε < Δθ1 < ε, it determines that the positioning accuracy requirement is met on the main unit side, and sets the main unit speed Vset1. n =0; If the positioning accuracy requirements are not met on the main unit side, the main unit's set speed Vset1 n =Vset1 n-1 +K p ×(Δθ1 n -Δθ1 n-1 )+K i ×Δθ1 n +K d ×(Δθ1 n -Δθ1 n-1 ×2+Δθ1 n-2 );

[0122] When -ε < Δθ2 < ε, it is determined that the positioning accuracy requirement is met from the generator side, and the generator set speed Vset2 is used. n =0; If the positioning accuracy requirement is not met from the unit side, the unit set speed Vset2 is used. n =Vset2 n-1 +K p ×(Δθ2 n -Δθ2 n-1 )+K i ×Δθ2 n +K d ×(Δθ2 n -Δθ2 n-1 ×2+Δθ2 n-2 If the set speed exceeds the maximum speed V. max Take the set speed as the maximum speed V max .

[0123] In summary, the main unit's set speed Vset1 and the slave unit's set speed Vset2 are:

[0124]

[0125]

[0126] S3: Input for calculating the speed loop

[0127] Calculate the single rotational speed increment based on the maximum acceleration and cycle period, and give the output rotational speed;

[0128] To ensure smooth start-up and shutdown of antenna array 1, the maximum acceleration a of antenna array 1 during rotation is limited. max The cycle period is defined as Δt = 10ms. The velocity increment of antenna array 1 in each cycle of the acceleration and deceleration phase is calculated. Combined with the reduction ratio n of motor reducer 11, the velocity increment of motor speed in each cycle is calculated as ΔV = a × Δt × n.

[0129] When the PLC processes the nth cycle, the main unit outputs the rotational speed.

[0130] Output speed of the unit

[0131] S4: Calculate the output of the speed loop.

[0132] The speed loop PID calculation is based on the master unit set speed Iset1 and slave unit set speed Iset2. Motor speed feedback Vrec1 and Vrec2 are collected, and the speed difference ΔV1 = Vout1 - Vrec1 and ΔV2 = Vout2 - Vrec2 are calculated.

[0133] When the PLC processes the nth cycle:

[0134]

[0135]

[0136] The PID parameters here are not the same set of data as in step S2.

[0137] S5: Calculate current loop input and output

[0138] Based on experience, the bias current of the master unit is given as i1 = 2.5A and the bias current of the slave unit is given as i2 = 2.5A. The output currents of the master unit, slave ...

[0139] like Figure 4 As shown, Figure 4 This is a graph showing the current changes of each motor during the flipping motion.

[0140] The internal drive board of the servo driver calculates the output voltage based on the output current, and drives the servo motor to output torque.

[0141] S6: Determine whether the difference between the current system angle and the target angle meets the accuracy requirements;

[0142] When -ε < Δθ1 < ε and -ε < Δθ2 < ε, it is determined that the difference between the current angle of the system and the target angle meets the positioning accuracy requirements.

[0143] Set Vset1 = 0, Vset2 = 0, and return to step S3;

[0144] Wait for the main motor 6 and the slave motor 8 to decelerate to a stop. The main motor current Iout1 = -i1, the main auxiliary current Iout2 = i1, the slave current Iout3 = -i2, and the slave auxiliary current Iout4 = i2. The flipping and positioning process ends.

[0145] If the above conditions are not met, return to step S1.

[0146] Furthermore, the entire process cycle T ≤ 10ms, the servo controller uses a clock frequency f = 125kHz to acquire the angle of the pitch measurement device, and the corresponding angle acquisition time period T 采 ≤0.2ms.

[0147] like Figure 5 As shown, Figure 5 The graph shows the angle values ​​of the pitch measuring device and the target angle during the flipping operation. During the flipping of the array from -30° to 30°, the angle measurement feedback from the main unit side and the slave unit side almost overlapped, and the actual feedback angle data deviation was within 0.01°, which demonstrated a good synchronization effect.

[0148] Furthermore, the bias current i1 on the main unit side and the bias current i2 on the slave unit side in step S5 are fixed in direction, thereby ensuring that the meshing surfaces of the two transmission gears 4 do not change when the antenna array 1 is flipped in two directions, reducing accuracy loss.

[0149] Furthermore, in step S5, there is no situation where the current of both motors on one side is zero at the same time. The current on the main unit side and the slave unit side decreases linearly to the opposite direction. Based on the positive correlation between current and torque, it is assumed that there is motor output torque on both sides at any time, so that the antenna array 1 remains in a gap-free state during the flipping process.

[0150] In summary, the four-motor backlash elimination system and solution described above can achieve speed synchronization between the main unit and the slave unit, as well as backlash elimination for both motors, thus solving the problems of poor positioning accuracy and low-speed stability of antenna array 1. When the axial load direction changes due to antenna array 1 passing overhead, backlash elimination ensures positioning accuracy and stable flipping action near that angle. It exhibits better accuracy and stability than traditional antenna array flipping control systems and is worthy of widespread application.

[0151] The above description is merely a preferred embodiment of the present invention and is illustrative rather than restrictive. Those skilled in the art will understand that many changes, modifications, and even equivalents can be made within the spirit and scope defined by the claims of the present invention, all of which will fall within the protection scope of the present invention.

Claims

1. A four-motor anti-backlash system for large antenna array inversion control, characterized in that, The antenna array, the antenna overturning mechanism, the servo driving mechanism and the elevation angle measuring device, the antenna overturning mechanism is connected with the antenna array, the gravity center of the antenna overturning mechanism and the gravity center of the antenna array are located on the same horizontal line, the elevation angle measuring device is arranged on the two sides of the antenna array along the transverse axis direction of the antenna array, the elevation angle measuring device transmits the angle signal to the servo driving mechanism, and the servo driving mechanism drives the antenna overturning mechanism to overturn. The antenna overturning mechanism comprises two half tooth rings and four transmission gears, the two half tooth rings are vertically arranged on the back of the antenna array, and the two ends of the two half tooth rings are connected with the antenna array, wherein the two transmission gears are meshed with one of the half tooth rings, and the other two transmission gears are meshed with the other half tooth ring, and the four transmission gears are connected with the corresponding servo driving mechanism. The antenna overturning mechanism further comprises a plurality of connecting rods, and the two half tooth rings are connected through the plurality of connecting rods. The two half tooth rings are distributed along the longitudinal axis direction of the antenna array, and one end of each of the two half tooth rings is connected with the upper end surface of the antenna array, and the other end of each of the two half tooth rings is connected with the lower end surface of the antenna array. The servo driving mechanism comprises a servo motor, a servo driver and a servo controller, the elevation angle measuring device transmits the angle signal to the servo controller, the servo controller transmits the control signal to the servo driver, the servo driver is connected with the servo motor, and the output shaft of the servo motor is connected with the corresponding transmission gear. The servo motor is divided into a master group and a slave group, the master group comprises a master motor and a master auxiliary motor, the slave group comprises a slave motor and a slave auxiliary motor, one end of each of the master motor and the master auxiliary motor is connected with the corresponding servo driver, the other end of each of the master motor and the master auxiliary motor is connected with two transmission gears through a speed reducer, one end of each of the slave motor and the slave auxiliary motor is connected with the corresponding servo driver, and the other end of each of the master motor and the master auxiliary motor is connected with the other two transmission gears through the speed reducer. The method for eliminating backlash by using the four-motor backlash elimination system comprises the following steps: S1: calculating the angle difference between the current elevation angle measured by the elevation angle measuring device and the target angle S2: obtaining the set speed of the master group and the slave group according to the angle difference Servo controller receives target angle ; Reading the pitch angle value measured by the pitch angle measuring device: the pitch angle value measured by the pitch angle measuring device for the main unit is defined as , and the pitch angle value measured for the slave unit is defined as ; Computing the unit angle difference From the unit angle difference ; If the positioning accuracy requirement is met, step S6 is performed; The positioning accuracy is defined as ; judging whether the master group and the slave group meet the positioning accuracy requirement, and if not, calculating the master group setting rotating speed based on the position loop PID algorithm , the slave group setting rotating speed ; S3: calculating the output speed of the master group and the slave group The speed reducer of the motor has a speed reduction ratio n; Limiting the maximum acceleration of an antenna array flip ; Circulation time is defined as ; S4: calculating the set current of the master group and the slave group Computing antenna array velocity increments ; When the PLC processes the nth cycle, the host group output rotation speed ; From the engine output rotation speed ; When the PLC processes the nth cycle: Based on the speed loop PID calculation host group set current I , slave group set current ; Collecting master set motor speed feedback and slave set motor speed feedback ; Computing master set speed difference and slave set speed difference ; S5: calculating the output current and output voltage of each motor driver ； ； The internal driving board of the servo driver calculates the output voltage based on the output current of the master group and the slave group, and drives the servo motor to output torque; Empirically given host group bias current and slave group bias current ; Set the current I according to the master group in S4 and the slave group , respectively give the master output current , the master-slave output current , the slave output current and the slave-slave output current ; S6: judging whether the current angle difference of the system meets the accuracy requirement If the positioning accuracy requirement is not met, return to step S1. When and the system determines that the difference between the current angle and the target angle has met the positioning accuracy requirement. Set master group set rotation speed Set slave group set rotation speed Return to step S3 Wait for the master motor and the slave motor to decelerate to a stop, master output current , master auxiliary output current , slave motor output current , slave auxiliary output current , the flip positioning process is over; ​ 2. A four-motor anti-backlash system for large antenna array inversion control as claimed in claim 1, characterized in that, In the step S2, the master group sets a rotation speed , the slave group sets a rotation speed , and specifically includes the following steps: S21: when the PLC processes the nth cycle, if , it is judged that the host group side meets the positioning accuracy requirement, and the host group sets the rotating speed ; if the host group side does not meet the positioning accuracy requirement, the host group sets the rotating speed ; S22: When , it is determined that the positioning accuracy requirement is met from the slave unit side, the slave unit sets the rotation speed ; if the positioning accuracy requirement is not met from the slave unit side, the slave unit sets the rotation speed .

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