Joint friction torque characteristic identification method, device, equipment, medium and product

Abstract

The invention discloses a joint friction torque characteristic identification method, device and equipment, a medium and a product. The method comprises the steps that motor electrical parameters of a target joint in a current injection state are obtained; joint motor temperature and joint state data of the target joint at each instruction angular velocity during cyclic operation are obtained; wherein the cycle operation is to control the target joint to operate for a preset duration at each instruction angular velocity and operation mode; according to the motor electrical parameters and the joint state data, the friction torque of the target joint at each instruction angular velocity is determined; and according to the joint motor temperature and the friction torque corresponding to each instruction angular velocity, determining a corresponding friction torque characteristic identification result. By introducing the joint motor temperature, the friction torque characteristic identification result containing the incidence relation of the instruction angular speed, the friction torque and the joint motor temperature is generated, the accuracy of friction torque characteristic identification can be improved, and therefore optimization of the control performance of the joint is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of modular joints, and in particular, to a method, device, equipment, medium and product for identifying the friction torque characteristics of joints. Background Art

[0002] Identifying the friction torque characteristics of modular joints helps to optimize the control performance of the joints. In the prior art, since the temperature of the joint motor is not effectively considered in the test, the generated identification result of the friction torque characteristics is not accurate enough, thus affecting the control performance of the joints. Summary of the Invention

[0003] The present invention provides a method, device, equipment, medium and product for identifying the friction torque characteristics of joints. By introducing the temperature of the joint motor, accurate identification of the friction torque characteristics of modular joints is achieved, which helps to optimize the control performance of the joints.

[0004] According to one aspect of the present invention, there is provided a method for identifying the friction torque characteristics of joints, the method comprising:

[0005] Obtaining the electrical parameters of the motor of the target joint in the current injection state;

[0006] Obtaining the temperature of the joint motor and the joint state data at each commanded angular velocity when the target joint is running in a cycle; wherein, the cyclic operation is to control the target joint to run for a preset duration at each commanded angular velocity and operation mode;

[0007] Determining the friction torque of the target joint at each commanded angular velocity according to the electrical parameters of the motor and the joint state data;

[0008] Determining the corresponding identification result of the friction torque characteristics according to the temperature of the joint motor and the friction torque corresponding to each commanded angular velocity.

[0009] According to another aspect of the present invention, there is provided a device for identifying the friction torque characteristics of joints, the device comprising:

[0010] A parameter acquisition module, configured to acquire the electrical parameters of the motor of the target joint in the current injection state;

[0011] A data acquisition module, configured to acquire the temperature of the joint motor and the joint state data at each commanded angular velocity when the target joint is running in a cycle; wherein, the cyclic operation is to control the target joint to run for a preset duration at each commanded angular velocity and operation mode;

[0012] A friction torque determination module, configured to determine the friction torque of the target joint at each commanded angular velocity according to the electrical parameters of the motor and the joint state data;

[0013] An identification result determination module, configured to determine a corresponding identification result of the friction torque characteristic according to the joint motor temperature and the friction torque corresponding to each commanded angular velocity.

[0014] According to another aspect of the present invention, there is provided an electronic device, the electronic device comprising:

[0015] At least one processor; and

[0016] A memory communicatively connected to the at least one processor; wherein,

[0017] The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the joint friction torque characteristic identification method according to any embodiment of the present invention.

[0018] According to another aspect of the present invention, there is provided a computer-readable storage medium storing computer instructions for causing a processor to implement the joint friction torque characteristic identification method according to any embodiment of the present invention when executed.

[0019] According to another aspect of the present invention, there is provided a computer program product comprising a computer program which, when executed by a processor, implements the joint friction torque characteristic identification method according to any embodiment of the present invention.

[0020] The technical solution of the embodiment of the present invention is as follows: obtaining the motor electrical parameters of the target joint in the current injection state; obtaining the joint motor temperature and the joint state data at each commanded angular velocity when the target joint is running in a cycle; wherein, the cycle operation is to control the target joint to run for a preset duration at each commanded angular velocity and operation mode respectively; determining the friction torque of the target joint at each commanded angular velocity according to the motor electrical parameters and the joint state data; and determining the corresponding identification result of the friction torque characteristic according to the joint motor temperature and the friction torque corresponding to each commanded angular velocity. The joint friction torque characteristic identification method provided by the embodiment of the present invention can improve the accuracy of the friction torque characteristic identification by introducing the joint motor temperature and generating an identification result of the friction torque characteristic including the correlation among the commanded angular velocity, the friction torque and the joint motor temperature, thereby contributing to optimizing the control performance of the joint.

[0021] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. Description of the Drawings

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0023] Figure 1 is a flowchart of a method for identifying the joint friction torque characteristics provided in Embodiment 1 of the present invention;

[0024] Figure 2 is a schematic diagram of a two-phase circuit of a joint motor provided in Embodiment 1 of the present invention;

[0025] Figure 3 is a schematic structural diagram of a device for identifying the joint friction torque characteristics provided in Embodiment 2 of the present invention;

[0026] Figure 4 is a schematic structural diagram of an electronic device for implementing the method for identifying the joint friction torque characteristics of the embodiments of the present invention. Detailed Embodiments

[0027] In order to enable those skilled in the art to better understand the solutions of the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0028] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or are inherent to these processes, methods, products, or devices.

[0029] Embodiment 1

[0030] Figure 1The following is a flowchart of a method for identifying the friction torque characteristics of a joint provided in Embodiment 1 of the present invention. This embodiment is applicable to the situation of identifying the friction torque characteristics of a modular joint. This method can be executed by a joint friction torque characteristic identification device, which can be implemented in the form of hardware and / or software, and can be configured in an electronic device. As Figure 1 shown, a method for identifying the friction torque characteristics of a joint provided in Embodiment 1 specifically includes the following steps:

[0031] S110. Obtain the electrical parameters of the motor of the target joint in the current injection state.

[0032] Among them, the target joint can refer to the modular joint to be identified for friction torque characteristics, and a joint motor is configured in the target joint. The electrical parameters of the motor can refer to the electrical parameters corresponding to the joint motor, which can include phase resistance, phase inductance, etc.

[0033] The current injection state can be understood as a state in which a specific current signal is injected into the motor winding of the joint motor through an external circuit or a control algorithm during the test of the target joint. In the current injection state, by measuring the response of the joint motor, the electrical parameters of the joint motor can be identified.

[0034] In the embodiment of the present invention, a specific current signal can be injected into the target joint to be identified through an external circuit or a control algorithm. For example, it can be a sinusoidal current with a specific current amplitude, frequency, duration, and sampling rate. Then, the response data of the joint motor in the target joint in the current injection state is collected, such as phase current, bus voltage, phase voltage, etc. Finally, the phase resistance, phase inductance, and other electrical parameters of the joint motor are determined according to the collected response data and the motor circuit principle. Among them, the current injection methods can include but are not limited to: ① Using an external power supply to inject current into the target joint; ② Controlling the injected current of the target joint by adjusting the duty cycle of the Pulse Width Modulation (PWM) signal.

[0035] In one embodiment, the current injection test of the target joint can be performed for multiple current injection control cycles, and the cycles with relatively stable injected currents in the last few cycles can be selected for the identification of the electrical parameters of the motor, so as to improve the identification accuracy of the electrical parameters of the motor, thereby effectively improving the accuracy of the subsequent identification of the friction torque characteristics of the joint.

[0036] It should be understood that step S110 is to identify the relevant electrical parameters of the joint motor through the static test method of current injection, which can provide the required parameter data for the subsequent calculation of the friction torque of the target joint.

[0037] S120. Obtain the joint motor temperature and joint status data of the target joint at each commanded angular velocity during cyclic operation; where the cyclic operation is to control the target joint to operate for a preset duration at each commanded angular velocity and operating mode.

[0038] Among them, the cyclic operation can be understood as a dynamic test on the target joint, that is, controlling the target joint to be identified to operate for a certain preset duration at each preset commanded angular velocity and operating mode, and synchronously collecting the joint motor temperature and joint status data of the target joint at each commanded angular velocity. The joint motor temperature can be selected as the average value of the joint motor temperature collected during a certain preset duration when the joint motor operates at the commanded angular velocity. The joint status data can also be selected as the average value of the joint status parameters collected during a certain preset duration when the joint motor operates at the commanded angular velocity. The joint status data can include but is not limited to: motor torque current, motor speed, bus voltage, and phase voltage coefficient, etc.

[0039] Before performing the cyclic operation test on the target joint, different commanded angular velocity gradients and the preset duration of operation can be preset according to the rated angular velocity of the joint; at the same time, the joint operating mode can also be set. For example, it can include: the joint only operates forward, the joint only operates backward, the joint first operates forward for a preset duration and then operates backward for a preset duration, the joint first operates backward for a preset duration and then operates forward for a preset duration, etc. This embodiment does not make specific limitations on this.

[0040] In the embodiment of the present invention, after performing a static test of current injection on the target joint, a dynamic test can be further performed on it. Specifically, the target joint can be controlled according to the preset commanded angular velocity and operating mode, and the joint motor temperature and joint status data of the target joint at each commanded angular velocity can be synchronously collected.

[0041] In one embodiment, a dynamic test of multiple cyclic operation control cycles can be performed on the target joint, and the joint motor temperature and joint status data corresponding to each cyclic operation control cycle can be recorded, which helps to determine the friction torque characteristics of the target joint subsequently.

[0042] S130. Determine the friction torque of the target joint at each commanded angular velocity according to the motor electrical parameters and joint status data.

[0043] In the embodiment of the present invention, based on the motor electrical parameters and joint status data obtained from the foregoing tests, the back electromotive force constant of the joint motor can be first identified, and then the torque coefficient of the joint motor can be identified based on the back electromotive force constant. Further, based on the torque coefficient and torque current, the friction torque of the target joint at each commanded angular velocity can be identified.

[0044] S140. Determine the corresponding friction torque characteristic identification result according to the joint motor temperature and friction torque corresponding to each commanded angular velocity.

[0045] Among them, the friction torque characteristic identification result includes the correlation relationships among different commanded angular velocities, joint motor temperatures, and friction torques. The friction torque characteristic identification result can be represented in forms such as, but not limited to, a friction torque characteristic table, a friction torque characteristic curve, and a friction torque characteristic function.

[0046] In an embodiment of the present invention, after testing the joint motor temperature and friction torque of the target joint at each commanded angular velocity, a friction torque characteristic table, a friction torque characteristic curve, a friction torque characteristic function, etc., formed based on the correlation relationships among the commanded angular velocity, friction torque, and joint motor temperature can be used as the final friction torque characteristic identification result. Further, after obtaining the friction torque characteristic identification result, relevant control parameters of the target joint can be optimized and adjusted based on this friction torque characteristic identification result, thereby improving the control performance of the target joint.

[0047] The technical solution of the embodiment of the present invention includes: obtaining the motor electrical parameters of the target joint in the current injection state; obtaining the joint motor temperature and joint state data of the target joint at each commanded angular velocity during cyclic operation, where cyclic operation is to control the target joint to operate for a preset duration at each commanded angular velocity and operation mode; determining the friction torque of the target joint at each commanded angular velocity according to the motor electrical parameters and joint state data; and determining the corresponding friction torque characteristic identification result according to the joint motor temperature and friction torque corresponding to each commanded angular velocity. The joint friction torque characteristic identification method provided by the embodiment of the present invention can improve the accuracy of friction torque characteristic identification by introducing the joint motor temperature and generating a friction torque characteristic identification result including the correlation relationships among the commanded angular velocity, friction torque, and joint motor temperature, thereby helping to optimize the control performance of the joint.

[0048] Further, based on the above embodiment of the invention, obtaining the motor electrical parameters of the target joint in the current injection state in S110 specifically includes the following steps:

[0049] S1101. Obtain a pre-set cosine constant sequence, sine constant sequence, duty ratio adjustment coefficient, current loop period, and period sampling points;

[0050] S1102. Determine the first duty ratio signal as the product of the cosine constant sequence and the duty ratio adjustment coefficient, and determine the second duty ratio signal as the product of the sine constant sequence and the duty ratio adjustment coefficient;

[0051] S1103. During each current injection control cycle of the target joint, control the disconnection of the first target phase of the joint motor within the target joint, and inject currents into the second target phase and the third target phase of the joint motor by using the first pulse width modulation signal and the second pulse width modulation signal respectively, and synchronously collect the bus voltage and the phase current of the second target phase; wherein, the first pulse width modulation signal is generated based on the first duty ratio signal, and the second pulse width modulation signal is generated based on the second duty ratio signal;

[0052] S1104. Exclude the first preset number of current injection control cycles in the front, and determine the cosine current accumulation value and the sine current accumulation value based on the phase currents corresponding to the sampling points in the subsequent second preset number of current injection control cycles, the cosine constant sequence and the sine constant sequence, and record the ratio of the cosine current accumulation value to the second preset number as the cosine current average value, and record the ratio of the sine current accumulation value to the second preset number as the sine current average value;

[0053] S1105. Determine the current fundamental wave phasor corresponding to the second target phase based on the cosine current average value and the sine current average value;

[0054] S1106. Determine the voltage phasor by multiplying the bus voltage by the duty ratio adjustment coefficient, and determine the impedance phasor by taking the ratio of the voltage phasor to the current fundamental wave phasor;

[0055] S1107. Determine the current injection frequency based on the current loop period and the number of cycle sampling points;

[0056] S1108. Determine the corresponding phase resistance and phase inductance based on the circuit impedance calculation formula of the joint motor in the current injection state, the impedance phasor and the current injection frequency, and use the phase resistance and the phase inductance as the motor electrical parameters.

[0057] In the embodiment of the present invention, the process of performing the current injection static test on the target joint is as follows:

[0058] ① Obtain the pre-set cosine constant sequence COS_ARRAY, sine constant sequence SIN_ARRAY, duty ratio adjustment coefficient α, current loop period T and number of cycle sampling points N; wherein, the cosine constant sequence COS_ARRAY and the sine constant sequence SIN_ARRAY can be expressed as follows:

[0059] COS_ARRAY = [cos(0), cos(1 * 2pi / N), …, cos((N - 2) * 2pi / N), cos((N - 1) * 2pi / N)] SIN_ARRAY = [sin(0), sin(1 * 2pi / N), …, sin((N - 2) * 2pi / N), sin((N - 1) * 2pi / N)]

[0060] Among them, both the cosine constant sequence and the sine constant sequence have a period of N, and N can be assigned according to needs. The two constant sequences can be used to control the two phases of the joint motor to change sinusoidally.

[0061] ② Multiply the cosine constant sequence COS_ARRAY(i) (i ∈ [1, N - 1]) and the sine constant sequence SIN_ARRAY(i) by the duty cycle adjustment coefficient α respectively to obtain the corresponding first duty cycle signal and second duty cycle signal.

[0062] ③ In this embodiment, the joint motor is illustrated by taking a surface-mounted brushless DC motor as an example. In each current injection control cycle of the target joint, use the first duty cycle signal and the second duty cycle signal to generate the corresponding first PWM signal and second PWM signal, and while keeping the first target phase of the joint motor disconnected, use the generated first PWM signal and second PWM signal to inject corresponding current signals into the second target phase and the third target phase of the joint motor respectively, and synchronously collect the bus voltage and the phase current of the second target phase during the current injection. Exemplarily, the W phase of the joint motor can be controlled to be disconnected, and sinusoidal currents are injected into the V phase and the U phase of the joint motor through the first PWM signal and the second PWM signal respectively, and the phase current Current_v(i) of the V phase is collected using a current sensor, and the bus voltage U is collected using a voltage sensor dc The sampling period is the current loop period T for both.

[0063] It should be understood that since the phase resistances and phase inductances of the three phases in the joint motor are approximately equal, in the current injection test, only the phase current of any one of the second target phase and the third target phase needs to be sampled for subsequent identification of the phase resistance and phase inductance. Further, the phase currents of the second target phase and the third target phase can also be sampled. For example, the phase current of the V phase can be used for identification of the phase resistance and phase inductance, and the phase current of the U phase can be used to verify the identification of the phase resistance and phase inductance obtained previously, so as to improve the accuracy of the identification of the phase resistance and phase inductance.

[0064] ④ Since the injected current in the first few current injection control cycles in the current injection test is not stable, which will affect the accuracy of the subsequent identification results, the sampling data collected in the first preset number of current injection control cycles in the front can be discarded, and the sampling data in the second preset number of current injection control cycles in the back are selected for processing. Specifically, the phase current Current_v(i) (taking the V phase as an example here) corresponding to each sampling point in the G current injection control cycles in the back, as well as the cosine constant sequence COS_ARRAY(i) and the sine constant sequence SIN_ARRAY(i) are used for calculation to obtain the corresponding cosine current accumulation value Sum_v_cos and sine current accumulation value Sum_v_sin as follows:

[0065]

[0066] Wherein, M represents the total number of sampling points in G current injection control cycles, that is, M = G * N.

[0067] Next, the ratio of the cosine current cumulative value Sum_v_cos to the second preset quantity G can be denoted as the cosine current average value C1 = Sum_v_cos / G, and the ratio of the sine current cumulative value Sum_v_sin to the second preset quantity can be denoted as the sine current average value C2 = Sum_v_sin / G.

[0068] ⑤ It can be achieved that the current fundamental wave phasor Iv(1) of the V-phase current phasor Iv with a specific length is expressed as follows:

[0069]

[0070] Wherein, DFT represents the discrete Fourier transform.

[0071] Therefore, by using the cosine current average value C1 and the sine current average value C2, the current fundamental wave phasor Iv(1) corresponding to the second target phase, i.e., the V phase, can be determined.

[0072] ⑥ Since the impedance phasor Z can be expressed as the ratio of the voltage phasor U L to the current fundamental wave phasor Iv(1), thus Z = U L / Iv(1), where the voltage phasor U L can be obtained by multiplying the bus voltage U dc by the duty cycle adjustment coefficient α, that is, U L = α * U dc .

[0073] ⑦ Figure 2 This is the schematic diagram of the two-phase circuit of the joint motor provided in the first embodiment of the present invention. Based on this circuit schematic diagram, the circuit impedance calculation formula of the joint motor in the current injection state can be obtained as follows:

[0074] Z = 2 * R p + j * 2pi * f s *(2 * L p )

[0075] Wherein, the current injection frequency f s can be calculated from the current loop period T and the period sampling points N, that is, f s = 1 / (T * N); R p and L p respectively represent the phase resistance and the phase inductance.

[0076] It can be seen from the above circuit impedance calculation formula that the real part of the impedance phasor Z corresponds to the resistance component, and the imaginary part corresponds to the inductance component. Therefore, the phase resistance R p and the phase inductance L p can be calculated as follows:

[0077]

[0078] After the above static current injection test on the target joint, the corresponding motor electrical parameters, namely the phase resistance R p and the phase inductance L p can be identified.

[0079] Furthermore, based on the above embodiments of the invention, in S120, the joint motor temperature and joint state data at each commanded angular velocity during the cyclic operation of the target joint are obtained, which specifically include the following steps:

[0080] S1201. In each cyclic operation control period of the target joint, in the order of increasing commanded angular velocity, control the target joint to first run forward at a constant speed for a preset duration and then run backward at a constant speed for a preset duration at each commanded angular velocity, and synchronously collect the joint motor temperature and joint state data during the constant-speed operation at each commanded angular velocity; wherein, the joint state data includes: motor torque current, motor speed, bus voltage, and phase voltage coefficient;

[0081] S1202. Statistically collect and store the joint motor temperature and joint state data of the third preset number of cyclic operation control periods.

[0082] In the embodiments of the present invention, the process of performing a cyclic operation dynamic test on the target joint is as follows:

[0083] ① The commanded angular velocity gradient and the preset duration of operation can be initialized according to the rated angular velocity of the joint. Examples of the commanded angular velocity gradient and duration are as follows:

[0084] Angular velocity number Commanded angular velocity (rad / s) Duration (s) Velocity 1 0.01 10 Velocity 2 0.1 10 Velocity 3 0.5 10 Velocity 4 1.57 10 Velocity 5 2.36 10 Velocity 6 3.14 10

[0085] ② In each cyclic operation control period of the target joint, control the target joint to first run forward at a constant speed for a preset duration and then run backward at a constant speed for a preset duration at the first commanded angular velocity, and then switch to the next commanded angular velocity and repeat the execution until all commanded angular velocities have been run, which is confirmed as one cyclic operation control period; then switch to the next cyclic operation control period and repeat the execution until the preset number of cycle operations is reached. During the operation of each cyclic operation control period, it is necessary to collect the joint motor temperature and joint state data of the target joint during the constant-speed operation at each commanded angular velocity. Among them, the joint state data can include: motor torque current I Torq , motor speed Ω, bus voltage Udc and the phase voltage coefficient PhaseVoltFactor. Among them, for the joint motor temperature and joint status data, the average value of the corresponding sampling data of the target joint running at a constant commanded angular velocity for a certain preset duration can be selected. Exemplarily, during the period when the control target joint runs at a constant speed of 1 for 10 seconds, multiple joint motor temperatures and motor torque currents can be sampled. The average values can be taken for these multiple joint motor temperatures and multiple motor torque currents respectively, and then the obtained average joint motor temperature and average motor torque current are used as the joint motor temperature and motor torque current of the target joint at the corresponding commanded angular velocity.

[0086] ③ After completing the test of the third preset number of cycle operation control periods, the collected joint motor temperature and joint status data can be stored. Further, the corresponding flag bit can be set to stop the data storage operation.

[0087] In one embodiment, the dynamic test of the cycle operation control period can be continuously executed until the joint running-in duration is completed. During the production process or the initial operation stage of the modular joint, a certain period of running-in operation is required to enable each component to gradually adapt to the working conditions. This period of running-in operation is called the joint running-in duration. By setting the cycle operation dynamic test during the joint running-in stage, both the running-in of the target joint and the automatic identification of the friction torque characteristics can be achieved, killing two birds with one stone.

[0088] Further, based on the above invention embodiments, in S130, according to the motor electrical parameters and joint status data, determining the friction torque of the target joint at each commanded angular velocity specifically includes the following steps:

[0089] S1301. For each cycle operation control period of the target joint, obtain the motor torque current, motor speed, bus voltage, and phase voltage coefficient corresponding to the maximum commanded angular velocity in the joint status data;

[0090] S1302. Determine the phase voltage amplitude based on the bus voltage and the phase voltage coefficient;

[0091] S1303. Based on the phase voltage amplitude and the preset voltage phasor equation, determine the corresponding back electromotive force constant;

[0092] S1304. Based on the back electromotive force constant, call the preset torque coefficient calculation formula to determine the corresponding torque coefficient;

[0093] S1305. For each commanded angular velocity, determine the friction torque as the product of the motor torque current corresponding to the commanded angular velocity and the torque coefficient.

[0094] In the embodiments of the present invention, the determination process of the friction torque is as follows:

[0095] ① Considering that the higher the command angular velocity, the identified reverse electromotive force constant K e The more accurate it is, the joint state data corresponding to the maximum command angular velocity in each cycle control period (such as velocity 6 in the velocity gradient table above) can be selected to calculate the reverse electromotive force constant K. e Identification.

[0096] ② Taking vector torque control as an example, when the joint motor is running at a constant speed and steady state, the corresponding preset voltage phasor equation can be expressed as:

[0097]

[0098] Among them, the phase voltage amplitude U ph The bus voltage U dc And the phase voltage coefficient PhaseVoltFactor is determined, that is, U ph =1.15*(U dc / 2)*PhaseVoltFactor.

[0099] Phase U d and phase U q They are respectively expressed as follows:

[0100] U d =R p *I Torq +K e *Ω

[0101] U q =2*pi*Freq*L p *I Torq

[0102] Wherein, the motor electrical frequency Freq = Ω*P / 60, P is the number of motor pole pairs.

[0103] By combining the above preset voltage phasor equation, phasor U d Calculation formula and phase U q The calculation formula can be solved to obtain the reverse electromotive force constant K e .

[0104] ③ Based on the obtained reverse electromotive force constant K e , you can use the following preset torque coefficient calculation formula to determine the corresponding torque coefficient K T :

[0105]

[0106] ④ Based on the determined torque coefficient K T , the friction torque T corresponding to different command angular velocities can be determined f= K T *I Torq . The examples are as follows:

[0107] Angular velocity number Friction torque current Friction torque Velocity 1 <![CDATA[I Torq1 > <![CDATA[K T* I Torq1 > Velocity 2 <![CDATA[I Torq2 > <![CDATA[K T* I Torq2 > Velocity 3 <![CDATA[I Torq3 > <![CDATA[K T* I Torq3 > Velocity 4 <![CDATA[I Torq4 > <![CDATA[K T* I Torq4 > Velocity 5 <![CDATA[I Torq5 > <![CDATA[K T* I Torq5 > Velocity 6 <![CDATA[I Torq6 > <![CDATA[K T* I Torq6 >

[0108] In summary, for each cycle operation control period, a friction torque T can be identified f .

[0109] Further, on the basis of the above-mentioned invention embodiments, in S140, according to the joint motor temperature and the friction torque corresponding to each commanded angular velocity, the corresponding friction torque characteristic identification result is determined, which specifically includes the following steps:

[0110] S1401. For each cycle operation control period of the target joint, draw a corresponding friction torque characteristic table according to the joint motor temperature and the friction torque corresponding to each commanded angular velocity, and use the friction torque characteristic table as the friction torque characteristic identification result.

[0111] In the embodiments of the present invention, for each cycle operation control period of the target joint, the joint motor temperature and the friction torque obtained in the foregoing test can be used to draw a friction torque characteristic table composed of the correlation relationship among the commanded angular velocity, the friction torque, and the joint motor temperature respectively, and use this friction torque characteristic table as the friction torque characteristic identification result of the target joint. It can be understood that a friction torque characteristic table can be drawn for each cycle operation control period. For example, for the first cycle operation control period and the last cycle operation control period, the friction torque characteristic tables of the target joint in the cold state and the hot state can be drawn. The following is an example of the friction torque characteristic table corresponding to a certain cycle operation control period:

[0112]

[0113]

[0114] It should be understood that the above form of using the friction torque characteristic table as the friction torque characteristic identification result is only an example. In practical applications, other forms such as relationship curves and function expressions can also be used, and this embodiment does not make specific limitations on this.

[0115] Further, on the basis of the above-mentioned invention embodiments, a method for identifying the joint friction torque characteristic provided by the embodiments of the present invention further includes:

[0116] Optimizing the control parameters of the target joint based on the friction torque characteristic identification result.

[0117] In an embodiment of the present invention, after obtaining the friction torque characteristic identification result, relevant control parameters of the target joint can also be optimized and adjusted based on the friction torque characteristic identification result. For example, corresponding friction compensation can be added or corrected in the motor control algorithm based on the identified friction torque characteristic, so as to reduce the influence of friction on the joint motor and improve the control accuracy, dynamic response, and energy efficiency of the joint.

[0118] Embodiment 2

[0119] Figure 3 FIG. is a schematic structural diagram of a joint friction torque characteristic identification device provided in Embodiment 2 of the present invention. As Figure 3 shown, the device includes:

[0120] A parameter acquisition module 21, configured to acquire the motor electrical parameters of the target joint in the current injection state;

[0121] A data acquisition module 22, configured to acquire the joint motor temperature and joint state data at each commanded angular velocity when the target joint runs in a cycle; wherein, the cyclic operation is to control the target joint to run for a preset duration at each commanded angular velocity and operation mode;

[0122] A friction torque determination module 23, configured to determine the friction torque of the target joint at each commanded angular velocity according to the motor electrical parameters and the joint state data;

[0123] An identification result determination module 24, configured to determine the corresponding friction torque characteristic identification result according to the joint motor temperature and the friction torque corresponding to each commanded angular velocity.

[0124] Further, based on the above-mentioned embodiment of the invention, the parameter acquisition module 21 includes:

[0125] A parameter acquisition unit, configured to acquire a preset cosine constant sequence, sine constant sequence, duty ratio adjustment coefficient, current loop period, and period sampling points;

[0126] A duty ratio signal determination unit, configured to determine the first duty ratio signal by multiplying the cosine constant sequence by the duty ratio adjustment coefficient, and determine the second duty ratio signal by multiplying the sine constant sequence by the duty ratio adjustment coefficient;

[0127] A current injection unit, configured to control the disconnection of the first target phase of the joint motor in the target joint during each current injection control period, and inject currents into the second target phase and the third target phase of the joint motor by using the first pulse width modulation signal and the second pulse width modulation signal respectively, and synchronously collect the bus voltage and the phase current of the second target phase; wherein, the first pulse width modulation signal is generated based on the first duty ratio signal, and the second pulse width modulation signal is generated based on the second duty ratio signal;

[0128] An average current determination unit, configured to exclude the first preset number of current injection control cycles at the front, and based on the phase currents corresponding to each sampling point, the cosine constant sequence, and the sine constant sequence in the second preset number of current injection control cycles at the back, determine the cosine current accumulation value and the sine current accumulation value, and record the ratio of the cosine current accumulation value to the second preset number as the cosine current average value, and record the ratio of the sine current accumulation value to the second preset number as the sine current average value;

[0129] A fundamental current phasor determination unit, configured to determine the fundamental current phasor corresponding to the second target based on the cosine current average value and the sine current average value;

[0130] An impedance phasor determination unit, configured to determine the product of the bus voltage and the duty cycle adjustment coefficient as the voltage phasor, and determine the ratio of the voltage phasor to the fundamental current phasor as the impedance phasor;

[0131] A current injection frequency determination unit, configured to determine the current injection frequency based on the current loop period and the number of cycle sampling points;

[0132] A motor electrical parameter determination unit, configured to determine the corresponding phase resistance and phase inductance based on the circuit impedance calculation formula of the joint motor in the current injection state, the impedance phasor, and the current injection frequency, and use the phase resistance and the phase inductance as the motor electrical parameters.

[0133] Further, based on the above-mentioned invention embodiment, the data acquisition module 22 includes:

[0134] A cyclic operation control unit, configured to, within each cyclic operation control cycle of the target joint, in a manner of increasing the commanded angular velocity, control the target joint to first run forward at a constant speed for a preset duration and then run backward at a constant speed for a preset duration at each commanded angular velocity, and synchronously collect the joint motor temperature and joint state data during the constant-speed operation at each commanded angular velocity; wherein, the joint state data includes: motor torque current, motor speed, bus voltage, and phase voltage coefficient;

[0135] A data storage unit, configured to count and store the joint motor temperature and joint state data of the third preset number of cyclic operation control cycles.

[0136] Further, based on the above-mentioned invention embodiment, the friction torque determination module 23 includes:

[0137] A data acquisition unit, configured to, for each cyclic operation control cycle of the target joint, acquire the motor torque current, motor speed, bus voltage, and phase voltage coefficient corresponding to the maximum commanded angular velocity in the joint state data;

[0138] A phase voltage amplitude determination unit, configured to determine the phase voltage amplitude based on the bus voltage and the phase voltage coefficient;

[0139] A back electromotive force constant determination unit, configured to determine the corresponding back electromotive force constant based on the phase voltage amplitude and a preset voltage phasor equation;

[0140] A torque coefficient determination unit, configured to call a preset torque coefficient calculation formula to determine the corresponding torque coefficient based on the back electromotive force constant;

[0141] A friction torque determination unit, configured to, for each commanded angular velocity, determine the product of the motor torque current corresponding to the commanded angular velocity and the torque coefficient as the friction torque.

[0142] Further, based on the above-mentioned invention embodiments, the identification result determination module 24 includes:

[0143] An identification result determination unit, configured to, for each cycle operation control period of a target joint, draw a corresponding friction torque characteristic table according to the joint motor temperature and the friction torque respectively corresponding to each commanded angular velocity, and use the friction torque characteristic table as the friction torque characteristic identification result.

[0144] Further, based on the above-mentioned invention embodiments, the joint friction torque characteristic identification device further includes:

[0145] A parameter optimization module, configured to optimize the control parameters of the target joint based on the friction torque characteristic identification result.

[0146] The joint friction torque characteristic identification device provided by the embodiments of the present invention can execute the joint friction torque characteristic identification method provided by any embodiment of the present invention, and has the corresponding functional modules and beneficial effects for executing the method.

[0147] Embodiment III

[0148] Figure 4 FIG. shows a schematic structural diagram of an electronic device 30 that can be used to implement the embodiments of the present invention. The electronic device is intended to represent various forms of digital computers, such as, a laptop computer, a desktop computer, a workbench, a personal digital assistant, a server, a blade server, a mainframe computer, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as, a personal digital processor, a cellular phone, a smart phone, a wearable device (such as a helmet, glasses, a watch, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the present invention described herein and / or claimed.

[0149] As Figure 4As shown, the electronic device 30 includes at least one processor 31 and a memory communicatively connected to the at least one processor 31, such as a read-only memory (ROM) 32, a random access memory (RAM) 33, etc. The memory stores a computer program executable by the at least one processor. The processor 31 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 32 or the computer program loaded from the storage unit 38 into the random access memory (RAM) 33. In the RAM 33, various programs and data required for the operation of the electronic device 30 can also be stored. The processor 31, the ROM 32, and the RAM 33 are connected to each other via a bus 34. An input / output (I / O) interface 35 is also connected to the bus 34.

[0150] Multiple components in the electronic device 30 are connected to the I / O interface 35, including: an input unit 36, such as a keyboard, a mouse, etc.; an output unit 37, such as various types of displays, speakers, etc.; a storage unit 38, such as a magnetic disk, an optical disk, etc.; and a communication unit 39, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 39 allows the electronic device 30 to exchange information / data with other devices via a computer network such as the Internet and / or various telecommunication networks.

[0151] The processor 31 can be various general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the processor 31 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 31 executes the various methods and processes described above, such as the joint friction torque characteristic identification method.

[0152] In some embodiments, the joint friction torque characteristic identification method can be implemented as a computer program tangibly embodied in a computer-readable storage medium, such as the storage unit 38. In some embodiments, part or all of the computer program can be loaded and / or installed onto the electronic device 30 via the ROM 32 and / or the communication unit 39. When the computer program is loaded into the RAM 33 and executed by the processor 31, one or more steps of the joint friction torque characteristic identification method described above can be executed. Alternatively, in other embodiments, the processor 31 can be configured to execute the joint friction torque characteristic identification method in any other appropriate manner (e.g., by means of firmware).

[0153] The various embodiments of the systems and techniques described above in this document can be implemented in digital electronic circuitry, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on a chip (SOCs), complex programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments can include: being implemented in one or more computer programs that are executable and / or interpretable on a programmable system including at least one programmable processor, which can be a special-purpose or general-purpose programmable processor that receives data and instructions from a storage system, at least one input device, and at least one output device, and transmits the data and instructions to the storage system, the at least one input device, and the at least one output device.

[0154] In some embodiments, the joint friction torque characteristic identification method can be implemented as a computer program that is invisibly contained in a computer program product. The computer program, when executed by a processor, implements the joint friction torque characteristic identification method of the present invention. The computer program product can be understood as a software product that mainly implements its solution through the computer program. The computer program for implementing the method of the present invention can be written in any combination of one or more programming languages. These computer programs can be provided to the processor of a general-purpose computer, a special-purpose computer, or other programmable data processing devices, such that when the computer program is executed by the processor, the functions / operations specified in the flowchart and / or block diagram are implemented. The computer program can be executed entirely on the machine, partially on the machine, executed partially on the machine as an independent software package and partially on a remote machine, or executed entirely on a remote machine or server.

[0155] In the context of the present invention, a computer-readable storage medium can be a tangible medium that can contain or store a computer program for use by or in connection with an instruction execution system, apparatus, or device. The computer-readable storage medium can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. Alternatively, the computer-readable storage medium can be a machine-readable signal medium. More specific examples of the machine-readable storage medium would include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0156] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or a trackball) through which the user can provide input to the electronic device. Other kinds of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0157] The systems and techniques described herein can be implemented in a computing system including backend components (e.g., as a data server), or a computing system including middleware components (e.g., an application server), or a computing system including frontend components (e.g., a user computer having a graphical user interface or a web browser through which the user can interact with an implementation of the systems and techniques described herein), or a computing system including any combination of such backend components, middleware components, or frontend components. The components of the system can be interconnected to each other by digital data communication in any form or medium (e.g., a communication network). Examples of communication networks include: local area network (LAN), wide area network (WAN), blockchain network, and the Internet.

[0158] A computing system can include a client and a server. The client and the server are generally far from each other and typically interact through a communication network. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or a cloud host, which is a host product in the cloud computing service system, and solves the defects of difficult management and weak business scalability existing in traditional physical hosts and VPS services.

[0159] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps recited in the present invention can be executed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved, and no limitation is imposed herein.

[0160] The above specific embodiments do not constitute a limitation on the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for identifying joint friction torque characteristics, characterized in that: The method comprises: Obtain the motor electrical parameters of the target joint under current injection state; Acquire the joint motor temperature and joint state data of the target joint at each command angular velocity during cyclic operation; wherein the cyclic operation is to control the target joint to run for a preset time at each command angular velocity and operation mode; Determining the friction torque of the target joint at each command angular velocity according to the motor electrical parameters and the joint state data; According to the joint motor temperature and the friction torque corresponding to each of the command angular velocities, a corresponding friction torque characteristic identification result is determined.

2. The method according to claim 1, characterized in that: The step of obtaining the motor electrical parameters of the target joint under the current injection state includes: Obtain the preset cosine constant sequence, sine constant sequence, duty cycle adjustment coefficient, current loop period and period sampling points; Determine the product of the cosine constant sequence and the duty cycle adjustment coefficient as a first duty cycle signal, and determine the product of the sine constant sequence and the duty cycle adjustment coefficient as a second duty cycle signal; In each current injection control cycle of the target joint, the first target phase of the joint motor in the target joint is controlled to be disconnected, and the first pulse width modulation signal and the second pulse width modulation signal are used to inject current into the second target phase and the third target phase of the joint motor respectively, and the bus voltage and the phase current of the second target phase are synchronously collected; wherein the first pulse width modulation signal is generated based on the first duty cycle signal, and the second pulse width modulation signal is generated based on the second duty cycle signal; Eliminating the first preset number of the current injection control cycles, determining the cosine current cumulative value and the sine current cumulative value based on the phase current corresponding to each sampling point in the second preset number of the current injection control cycles and the cosine constant sequence and the sine constant sequence, and recording the ratio of the cosine current cumulative value to the second preset number as the cosine current average value, and recording the ratio of the sine current cumulative value to the second preset number as the sine current average value; Determine a current fundamental phasor corresponding to the second target based on the cosine current average value and the sine current average value; Determine the product of the bus voltage and the duty cycle adjustment coefficient as a voltage phasor, and determine the ratio of the voltage phasor to the current fundamental wave phasor as an impedance phasor; Determining a current injection frequency based on the current loop period and the number of sampling points in the period; Based on the circuit impedance calculation formula of the joint motor in the current injection state, the impedance phasor and the current injection frequency, the corresponding phase resistance and phase inductance are determined, and the phase resistance and the phase inductance are used as the motor electrical parameters.

3. The method according to claim 1, characterized in that The step of obtaining the joint motor temperature and joint state data of the target joint at each command angular velocity during cyclic operation includes: In each cyclic operation control period of the target joint, the target joint is controlled to first run forward at a constant speed for a preset time period and then run reverse at a constant speed for a preset time period at each command angular velocity in a manner of increasing the command angular velocity, and the joint motor temperature and the joint state data under the constant speed operation at each command angular velocity are synchronously collected; wherein the joint state data includes: motor torque current, motor speed, bus voltage and phase voltage coefficient; The joint motor temperature and the joint status data of a third preset number of the cyclic operation control cycles are counted and stored.

4. The method according to claim 1, characterized in that: The step of determining the friction torque of the target joint at each command angular velocity according to the motor electrical parameters and the joint state data comprises: For each cyclic operation control period of the target joint, the motor torque current, motor speed, bus voltage and phase voltage coefficient corresponding to the maximum command angular velocity in the joint state data are obtained; determining a phase voltage amplitude based on the bus voltage and the phase voltage coefficient; Determining a corresponding back electromotive force constant based on the phase voltage amplitude and a preset voltage phasor equation; Based on the back electromotive force constant, a preset torque coefficient calculation formula is called to determine a corresponding torque coefficient; For each of the command angular velocities, the friction torque is determined as a product of a motor torque current corresponding to the command angular velocity and the torque coefficient.

5. The method according to claim 1, characterized in that The determining of the corresponding friction torque characteristic identification result according to the joint motor temperature and the friction torque corresponding to each of the command angular velocities includes: For each cyclic operation control cycle of the target joint, a corresponding friction torque characteristic table is drawn according to the joint motor temperature and the friction torque corresponding to each command angular velocity, and the friction torque characteristic table is used as the friction torque characteristic identification result.

6. The method according to claim 1, characterized in that Also includes: The control parameters of the target joint are optimized based on the friction torque characteristic identification result.

7. A joint friction torque characteristic identification device, characterized in that: The device comprises: A parameter acquisition module is used to obtain the motor electrical parameters of the target joint under the current injection state; A data acquisition module, used to acquire the joint motor temperature and joint state data of the target joint at each command angular velocity during cyclic operation; wherein the cyclic operation is to control the target joint to run for a preset time at each command angular velocity and operation mode; A friction torque determination module, used for determining the friction torque of the target joint at each command angular velocity according to the motor electrical parameters and the joint state data; The identification result determination module is used to determine the corresponding friction torque characteristic identification result according to the joint motor temperature and the friction torque corresponding to each of the command angular velocities.

8. An electronic device, characterized in that: The electronic device comprises: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can perform the joint friction torque characteristic identification method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the joint friction torque characteristic identification method according to any one of claims 1 to 6 when executed.

10. A computer program product, characterized in that The computer program product comprises a computer program, and when the computer program is executed by a processor, the method for identifying joint friction torque characteristics according to any one of claims 1 to 6 is implemented.

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