Torque Motor Drive Control Method and Robot Joint

Abstract

The present invention relates to a torque motor drive control method and robot shutdown. The torque motor drive control method includes the following steps: the driver reads the torque T collected by the torque sensor L and the joint rotation angle θ collected by the output encoder at the output end r ; the driver calculates the deformation amount θ0 of the torque sensor and the deformation amount θ1 of the harmonic reducer according to the torque T L ; the driver calculates the electrical angle θ of the rotor of the joint torque motor through the electrical angle calculation formula e , and the electrical angle calculation formula is θ e =(θ r -θ0-θ1)*γ / p, where γ is the reduction ratio and p is the number of pole pairs of the torque motor; and the driver calculates the vector control of the torque motor and the speed of the motor rotor according to the electrical angle θ of the rotor of the joint torque motor e . It can achieve the full closed-loop control of the robot joint without the output encoder at the motor end, with a simple system structure, low cost and high reliability.

Description

Technical Field

[0001] The present invention relates to the technical field of robots, and in particular to a torque motor drive control method and a robot joint. Background Art

[0002] Collaborative robot joints generally adopt a dual-encoder configuration. The two encoders are respectively installed at the motor end and the joint output end. Using two encoders increases the volume, weight, and complexity of the collaborative robot joint, and also increases the cost.

[0003] Currently, there are also some collaborative robot joints that adopt a single-encoder method. Most of them install the encoder at the motor shaft end. Since there is no corresponding position detection element at the output end, it is necessary to estimate the position information of the joint output end by calculating the deformation of transmission mechanisms such as harmonic reducers. Substantially, it is a semi-closed-loop servo system, and the control accuracy of the output end cannot be guaranteed. Summary of the Invention

[0004] Based on this, in order to solve the problem that the control accuracy of the output end of a robot joint with a single encoder cannot be guaranteed, a torque motor drive control method and a robot joint are provided.

[0005] The present application first provides a torque motor drive control method, including the following steps:

[0006] The driver reads the torque T collected by the torque sensor L and the joint rotation angle θ collected by the output end encoder r ;

[0007] The driver calculates the deformation amount θ0 of the torque sensor and the deformation amount θ1 of the harmonic reducer according to the torque T L ;

[0008] The driver calculates the electrical angle θ of the rotor of the joint torque motor through the electrical angle calculation formula e , and the electrical angle calculation formula is θ e =(θ r -θ0-θ1)*γ / p, where γ is the reduction ratio and p is the number of pole pairs of the torque motor; and

[0009] The driver performs torque motor vector control and motor rotor speed calculation according to the electrical angle θ of the rotor of the joint torque motor e .

[0010] In the above torque motor drive control method, the actual displacement and absolute position of the joint output end can be obtained through the output end encoder. At the same time, through the torque T L , the joint rotation angle θ rThe detection of the torque motor rotor position and the speed estimation can be calculated by simple parameters such as these, so as to achieve the full closed-loop control of the robot joint without the encoder at the motor output end. The system structure is simple, the cost is low, and the reliability is relatively high.

[0011] In one embodiment, the steps of calculating the deformation θ0 of the torque sensor and the deformation θ1 of the harmonic reducer include:

[0012] According to the torque T L , calculate the deformation θ0 of the torque sensor, where K0 is the torsional stiffness of the torque sensor;

[0013] According to the torque T L , calculate the deformation θ1 of the harmonic reducer, where K1, K2, and K3 are all spring constants when the torque of the harmonic reducer changes, and T1, T2, and T3 are the three-segment torque thresholds corresponding to K1, K2, and K3.

[0014] In one embodiment, between the step of calculating the electrical angle θ e by the electrical angle calculation formula and the step of calculating the vector control of the torque motor and the motor rotor speed according to the electrical angle θ e , the following step is further included:

[0015] Real-time observe the joint torque motor rotor through the motor rotor position observer and obtain the electrical angle θ e of the joint torque motor rotor.

[0016] In one embodiment, the motor rotor position observer is a back electromotive force observer, a magnetic flux observer, or a sliding mode observer.

[0017] In one embodiment, between the step of real-time observing the electrical angle θ e through the motor rotor position observer and the step of calculating the vector control of the torque motor and the motor rotor speed according to the electrical angle θ e of the joint torque motor rotor, the following step is further included:

[0018] Define the electrical angle θ e calculated by the electrical angle calculation formula as the calculated electrical angle θ e1 , and define the electrical angle θ e observed by the motor rotor position observer as the observed electrical angle θ e2 ;

[0019] The driver determines whether the rotational speed of the torque motor is higher than the set value;

[0020] Select the calculated electrical angle θ according to the judgment result e1 and the observed electrical angle θ e2 or the value obtained by combining the two as the electrical angle θ e for subsequent calculations.

[0021] In one embodiment, the step of selecting the electrical angle θ according to the judgment result e includes:

[0022] The driver determines whether the observed electrical angle θ e2 tends to be equal to the calculated electrical angle θ e1 ;

[0023] If the two values tend to be equal and the torque motor speed is higher than the set value, then select the observed electrical angle θ e2 as the electrical angle θ of the joint torque motor rotor e ;

[0024] If the two values tend to diverge and the torque motor speed is higher than the set value, then the motor rotor position observer re - observes or the robot joint stops and reports an error;

[0025] If the torque motor speed is lower than the set value, then select the calculated electrical angle θ e1 as the electrical angle θ of the joint torque motor rotor e 。

[0026] It can be understood that by selecting the electrical angle obtained through different channels when the torque motor speed is different, the observed electrical angle θ e can accurately obtain the electrical angle θ of the motor rotor within the full - speed range e so as to facilitate the detection of the motor rotor position and the estimation of the speed within the full - speed range through subsequent calculations, and further realize the servo control of the torque motor in the case of no motor - side encoder.

[0027] In one embodiment, the step of determining whether the torque motor speed is higher than the set value includes:

[0028] Set a first set speed and a second set speed, where the first set speed is less than the second set speed;

[0029] Determine whether the torque motor speed is higher than the first set speed and the second set speed.

[0030] In one embodiment, the step of selecting the electrical angle θ e includes:

[0031] If the torque motor speed is lower than the first set speed, then select the calculated electrical angle θ e1As the electrical angle θ of the joint torque motor rotor e ;

[0032] If the speed of the torque motor is between the first set speed and the second set speed, then the electrical angle θ obtained by calculation e1 , the observed electrical angle θ e2 and the electrical angle θ of the joint motor rotor calculated by the weight coefficient smooth switching formula e ;

[0033] If the speed of the torque motor is higher than the second set speed, then the observed electrical angle θ is selected e2 as the electrical angle θ of the joint torque motor rotor e .

[0034] It can be understood that when the speed of the torque motor is between the first set speed and the second set speed, based on the weight coefficient smooth switching formula, the weight coefficient is adjusted in real time according to the speed change, and the calculation of the electrical angle θ e1 and the observed electrical angle θ e2 can achieve a smooth transition between them.

[0035] In one embodiment, the weight coefficient smooth calculation formula is wherein, is a function of the speed .

[0036] The second aspect of the present application provides a robot joint, including an input housing, an output housing and a harmonic reducer. The input housing is rotatably connected to the output housing, and the harmonic reducer is located between them; a torque motor is arranged in the input housing, and a motor shaft is arranged in the torque motor; a flexspline shaft is arranged in the output housing; the harmonic reducer includes a wave generator, a flexspline and a rigid gear. The rigid gear is fixed to the input housing, the wave generator is fixed to one end of the motor shaft, the flexspline is sleeved on the outer peripheral surface of the wave generator and is fixedly connected to one end of the flexspline shaft, and the outer peripheral surface of the flexspline can mesh with the inner peripheral wall of the rigid gear; a torque sensor is arranged at the other end of the flexspline shaft, and an output encoder is arranged on the outer peripheral surface of the flexspline shaft; a joint driver is fixed to one end of the input housing away from the output housing, and the joint driver has interfaces corresponding to the torque sensor and the output encoder of another robot joint.

[0037] It can be understood that by setting the output end encoder in the output housing, the actual displacement and absolute position of the output end can be directly detected. At the same time, relying on the above-mentioned torque motor drive control method, the torque motor rotor position detection and speed estimation can be calculated. In the absence of a motor-end output encoder, full closed-loop control of the robot joint can be achieved. The system has a simple structure, low cost and high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0039] Figure 1 It is a flow chart of the torque motor driving control method of the present invention;

[0040] Figure 2 is a circuit diagram of a torque motor;

[0041] Figure 3 It is a flowchart diagram of some steps of the torque motor drive control method of the present invention;

[0042] Figure 4 It is a flowchart diagram of some steps of the torque motor drive control method of the present invention;

[0043] Figure 5 It is a flowchart diagram of some steps of the torque motor drive control method of the present invention;

[0044] Figure 6 It is a flowchart diagram of some steps of the torque motor drive control method of the present invention;

[0045] Figure 7 It is a flowchart diagram of some steps of the torque motor drive control method of the present invention;

[0046] Figure 8 It is a function diagram of the weight coefficient in the present invention;

[0047] Figure 9 It is a schematic diagram of the front view structure of the robot joint of the present invention after being cut open.

[0048] Reference Numerals: 10, input housing; 11, torque motor; 11a, stator; 11b, rotor; 12, motor shaft; 13, bearing seat; 14, first bearing; 15, brake; 20, output housing; 20a, flange connection part; 20b, body part; 21, flexspline shaft; 22, torque sensor; 23, output encoder; 24, second bearing; 25, encoder connection part; 30, harmonic reducer; 31, wave generator; 32, flexspline; 33, circular spline. Detailed Embodiment

[0049] In order to make the above objects, features, and advantages of the present application more obvious and understandable, the following will describe the detailed embodiments of the present application with reference to the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0050] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it can be directly on the other component or there can also be an intermediate component. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be an intermediate component at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in the description of the present application are only for the purpose of illustration and do not represent the only implementation manner.

[0051] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0052] In the present application, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature can be that the first feature is in direct contact with the second feature, or the first feature and the second feature are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the first feature has a lower horizontal height than the second feature.

[0053] Unless otherwise defined, all technical and scientific terms used in the specification of this application have the same meaning as commonly understood by those skilled in the technical field to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in the specification of this application includes any and all combinations of one or more of the related listed items.

[0054] Please refer to Figure 1 As shown, this application first provides a torque motor drive control method, including the following steps:

[0055] S100. The driver reads the torque T collected by the torque sensor L and the joint rotation angle θ collected by the output end encoder r ;

[0056] S200. The driver calculates the deformation amount θ0 of the torque sensor and the deformation amount θ1 of the harmonic reducer according to the torque T L ;

[0057] S300. The driver calculates the electrical angle θ of the rotor of the joint torque motor through the electrical angle calculation formula e , and the electrical angle calculation formula is θ e =(θ r -θ0-θ1)*γ / p, where γ is the reduction ratio and p is the number of pole pairs of the torque motor;

[0058] S800. The driver calculates the vector control of the torque motor and the speed of the motor rotor according to the electrical angle θ of the rotor of the joint torque motor e ;

[0059] The output end encoder can obtain the actual displacement and absolute position of the joint output end. At the same time, through simple parameters such as the torque T L , the joint rotation angle θ r , etc., the detection of the position of the torque motor rotor and the speed estimation can be calculated, so as to realize the full closed-loop control of the robot joint without the output end encoder at the motor end, and the system structure is simple, the cost is low, and the reliability is high.

[0060] Among them, step S800 is a conventional technical means in this field. Specifically, please refer to Figure 2 As shown, after obtaining the electrical angle θ of the rotor of the joint torque motor e , the driver collects the three-phase currents Ia, Ib, and Ic of the motor, and combines the obtained electrical angle θ of the motor rotor e, coordinate transformation (Clark, Park), obtain decoupled vector currents Id, Iq, and use PI controllers to perform closed-loop control on Id, Iq, respectively, so that Id, Iq track their respective command values ​​Id_ref, Iq_ref; Vq, Vd output by the control PI device and the measured electrical angle θ e , perform inverse Park transform and space vector modulation (SVPWM) to control the driver's three-phase inverter bridge output Va, Vb, and Vc, thereby completing the torque motor vector control.

[0061] Please refer to Figure 3 As shown, in some embodiments, step S200 includes:

[0062] S210, according to the torque T L , calculate the deformation variable θ0 of the torque sensor, Where K0 is the torsional stiffness of the torque sensor;

[0063] S220, according to the torque TL, calculate the deformation variable θ1 of the harmonic reducer, Among them, K1, K2 and K3 are spring constants when the torque of the harmonic reducer changes, and T1, T2 and T3 are three-stage torque thresholds corresponding to K1, K2 and K3.

[0064] Please refer to Figure 4 As shown, in some embodiments, between step S300 and step S800, the following steps are further included:

[0065] S400, observe the joint torque motor rotor in real time through the motor rotor position observer, and obtain the joint torque motor rotor electrical angle θ e .

[0066] In some embodiments, the motor rotor position observer is a back electromotive force observer, a flux observer or a sliding film observer.

[0067] Of course, the motor position observer can also be other observers, as long as it can directly observe the electrical angle θ of the joint torque motor rotor. e That's it.

[0068] Please refer to Figure 5 As shown, in some embodiments, between step S400 and step S800, the following steps are further included:

[0069] S500, the electrical angle θ calculated by the electrical angle calculation formula e Defined as the calculated electrical angle θ e1 , the electrical angle θ obtained by the motor rotor position observer e Defined as the observed electrical angle θ e2;

[0070] S600. The driver determines whether the rotational speed of the torque motor is higher than the set value;

[0071] S700. Select the calculated electrical angle θ e1 , the observed electrical angle θ e2 or the value obtained by combining the two as the electrical angle θ e for subsequent calculations.

[0072] Please refer to Figure 6 shown. In some embodiments, step S700 includes:

[0073] S710. The driver determines whether the observed electrical angle θ e2 and the calculated electrical angle θ e1 tend to be equal;

[0074] S720. If the two values tend to be equal and the rotational speed of the torque motor is higher than the set value, then select the observed electrical angle θ e2 as the electrical angle θ of the rotor of the joint torque motor e ; if the two values tend to diverge and the rotational speed of the torque motor is higher than the set value, then the motor rotor position observer re - observes or the robot joint stops and reports an error; if the rotational speed of the torque motor is lower than the set value, then select the calculated electrical angle θ e1 as the electrical angle θ of the rotor of the joint torque motor e .

[0075] By selecting the electrical angle obtained through different paths when the rotational speed of the torque motor is different, the observed electrical angle θ e , the electrical angle θ of the motor rotor within the full - speed range can be accurately obtained e , so as to facilitate the detection of the motor rotor position and the estimation of the speed within the full - speed range through subsequent calculations, and further realize the servo control of the torque motor in the case of no encoder at the motor end.

[0076] Please refer to Figure 7 shown. In some embodiments, step S600 includes:

[0077] S610. Set a first set rotational speed and a second set rotational speed, where the first set rotational speed is less than the second set rotational speed;

[0078] S620. Determine whether the rotational speed of the torque motor is higher than the first set rotational speed and the second set rotational speed.

[0079] In the above - mentioned embodiments, step S700 includes:

[0080] If the rotational speed of the torque motor is lower than the first set rotational speed, then select the calculated electrical angle θ e1 as the electrical angle θ of the rotor of the joint torque motor e ; if the rotational speed of the torque motor is between the first set rotational speed and the second set rotational speed, then through the calculated electrical angle θ e1 , the observed electrical angle θ e2 and the weight coefficient smooth switching formula to calculate the electrical angle θ of the joint motor rotor e ; if the rotational speed of the torque motor is higher than the second set rotational speed, then select the observed electrical angle θ e2 as the electrical angle θ of the rotor of the joint torque motor e .

[0081] In this application, when the rotational speed of the torque motor is between the first set rotational speed and the second set rotational speed, based on the weight coefficient smooth switching formula, the weight coefficient is adjusted in real time according to the rotational speed change, and it is possible to complete the smooth transition between the calculated electrical angle θ e1 and the observed electrical angle θ e2 .

[0082] Please refer to Figure 8 shown. In some embodiments, the weight coefficient smooth calculation formula is wherein, is a function of the speed .

[0083] Please refer to Figure 9 shown. A second aspect of this application provides a robot joint, including an input housing 10, an output housing 20 and a harmonic reducer 30. The input housing 10 is rotatably connected to the output housing 20, and the harmonic reducer 30 is located therebetween; a torque motor 11 is arranged in the input housing 10, and a motor shaft 12 is arranged in the torque motor 11; a flexspline shaft 21 is arranged in the output housing 20; the harmonic reducer 30 includes a wave generator 31, a flexspline 32 and a rigid gear 33. The rigid gear 33 is fixed to the input housing 10, the wave generator 31 is fixed to one end of the motor shaft 12, the flexspline 32 is sleeved on the outer peripheral surface of the wave generator 31 and is fixedly connected to one end of the flexspline shaft 21. The outer peripheral surface of the flexspline 32 can mesh with the inner peripheral wall of the rigid gear 33; a torque sensor 22 is arranged at the other end of the flexspline shaft 21, and an output end encoder 23 is arranged on the outer peripheral surface of the flexspline shaft 21; a joint driver is fixedly arranged at one end of the input housing 10 away from the output housing 20, and the joint driver has interfaces corresponding to the torque sensor 22 and the output end encoder 23 of another robot joint.

[0084] By arranging the output end encoder 23 inside the output housing 20, the actual displacement and absolute position of the output end can be directly detected. At the same time, relying on the above-mentioned torque motor drive control method, the detection of the torque motor rotor position and speed estimation can be calculated. In the case of no encoder at the motor end output, the full closed-loop control of the robot joint can be realized, and the system structure is simple, the cost is low, and the reliability is high.

[0085] Specifically, a torque motor 11 is provided inside the input housing 10. The motor shaft 12 driven by the torque motor 11 has a power output end at the inner port of the input housing 10. The power output end of the motor shaft 12 drives the output housing 20 to make a relative rotational movement through a harmonic reducer 30.

[0086] Two sets of parallel bearing seats 13 are provided in the inner cavity of the input housing 10. The motor shaft 12 is rotatably arranged at the center of the input housing 10 through the first bearing 14 on the bearing seat 13. The stator 11a of the torque motor 11 is fixed between the two sets of bearing seats 13, and the rotor 11b of the torque motor 11 is fixedly connected to the outer wall of the motor shaft 12.

[0087] The steel wheel 33 of the harmonic reducer 30 is fixed at the inner port of the input housing 10. The flexible wheel 32 of the harmonic reducer 30 is connected to the flexible wheel shaft 21 inside the output housing 20. The wave generator 31 of the harmonic reducer 30 is installed at the power output end of the motor shaft 12.

[0088] The motor shaft 12 has two shoulders 12a fitted with the first bearing 14. The rotor 11b is installed between the two shoulders 12a. The power output end of the motor shaft 12 is fixedly connected to the wave generator 31 by screws, and a brake 15 is provided at the other end of the motor shaft 12.

[0089] The output housing 20 has a flange connection part 20a sleeved outside the input housing 10 and a body part 20b with a reduced diameter and axially extending. The flange connection part 20a is rotationally matched with the outer wall of the input housing 10 through the second bearing 24. The flexible wheel shaft 21 is located at the center of the body part 20b. One end of the flexible wheel shaft 21 is fixedly connected to the end face of the flexible wheel 32, and the other end of the flexible wheel shaft 21 is connected with a torque sensor 22 for detecting the external load.

[0090] An encoder connecting part 25 is arranged on the outer periphery of the flexible wheel shaft 21. The encoder connecting part 25 is provided with an output end encoder 23 for detecting the position signal of the flexible wheel connecting shaft. The output end encoder 23 is an absolute encoder.

[0091] A driver is provided at the outer end of the input housing 10. The driver is provided with corresponding interfaces for the aforementioned torque sensor 22 and output end encoder 23, and performs corresponding speed, position processing and operation control according to the received torque signal and output end encoder displacement signal.

[0092] In some embodiments, a motor rotor position observer is further provided in the input housing 10.

[0093] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0094] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the patent protection scope of the present application shall be subject to the appended claims.

Claims

1. A torque motor drive control method, characterized in that, The steps include the following: The driver reads the torque T collected by the torque sensor L and the joint rotation angle θ collected by the encoder at the output end r ; The driver calculates the deformation θ0 of the torque sensor and the deformation θ1 of the harmonic reducer based on the torque T L ​ The driver calculates the electrical angle θ of the joint torque motor rotor through the electrical angle calculation formula e , and the electrical angle calculation formula is θ e = (θ r - θ0 - θ1) * γ / p, where γ is the reduction ratio and p is the number of pole pairs of the torque motor; The motor rotor of the joint torque motor is observed in real time through a motor rotor position observer, and the electrical angle θ of the motor rotor of the joint torque motor is obtained e ; The electrical angle θ calculated through the electrical angle calculation formula e is defined as the calculated electrical angle θ e1 , and the electrical angle θ observed through the motor rotor position observer e is defined as the observed electrical angle θ e2 ; The driver determines whether the rotational speed of the torque motor is higher than the set value; Select the calculated electrical angle θ based on the judgment result e1 , the observed electrical angle θ e2 or the value obtained by combining the two as the electrical angle θ e for subsequent calculations; and The driver performs torque motor vector control and motor rotor speed calculation based on the electrical angle θ of the joint torque motor e to achieve the full closed-loop control of the robot joint; The step of selecting the electrical angle θ according to the judgment result e includes: the driver judges the observed electrical angle θ e2 and the calculated electrical angle θ e1 to determine whether they tend to be equal; If the two values tend to be equal and the speed of the torque motor is higher than the set value, then select the observed electrical angle θ e2 as the electrical angle θ of the rotor of the joint torque motor e ; If the two values tend to diverge and the rotational speed of the torque motor is higher than the set value, the motor rotor position observer re-observes or the robot joint stops and reports an error; If the rotational speed of the torque motor is lower than the set value, select the calculated electrical angle θ e1 as the electrical angle θ of the rotor of the joint torque motor e .

2. The torque motor drive control method according to claim 1, characterized in that The steps of calculating the deformation θ0 of the torque sensor and the deformation θ1 of the harmonic reducer include: According to the torque T L , calculate the deformation θ0 of the torque sensor, where K0 is the torsional stiffness of the torque sensor; According to the torque T L , calculate the deformation θ1 of the harmonic reducer Among them, K1, K2, and K3 are all spring constants when the torque of the harmonic reducer changes, and T1, T2, and T3 are the three-stage torque thresholds corresponding to K1, K2, and K3.

3. The torque motor drive control method according to claim 1, characterized in that The motor rotor position observer is a back electromotive force observer, a magnetic flux observer or a sliding mode observer.

4. The torque motor drive control method according to claim 1, wherein, The steps of determining whether the rotational speed of the torque motor is higher than the set value include: Set a first set rotational speed and a second set rotational speed, where the first set rotational speed is less than the second set rotational speed; Determine whether the rotational speed of the torque motor is higher than the first set rotational speed and the second set rotational speed.

5. The torque motor drive control method according to claim 4, wherein Select the electrical angle θ according to the judgment result e The steps include: If the rotational speed of the torque motor is lower than the first set rotational speed, then select the calculated electrical angle θ e1 as the electrical angle θ of the rotor of the joint torque motor e ; If the rotational speed of the torque motor is between the first set rotational speed and the second set rotational speed, then the electrical angle θ obtained through calculation e1 , the observed electrical angle θ e2 and the electrical angle θ of the rotor of the joint torque motor calculated by the weighted coefficient smooth switching formula e ; If the rotational speed of the torque motor is higher than the second set rotational speed, then select the observed electrical angle θ e2 as the electrical angle θ of the rotor of the joint torque motor e .

6. The torque motor drive control method according to claim 5, wherein, The weight coefficient smoothing calculation formula is where is the speed is a function of...

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