Limited angle motor angle redundancy detection method based on multiple angular displacement sensors

Abstract

The invention belongs to the technical field of motor angle measurement, and provides a finite angle motor angle redundancy detection method based on multiple angular displacement sensors in order to solve the problems that the direction of a detection magnetic field is single and errors exist during installation. The motor angle before the phase change and the motor angle after the phase change are calculated, and motor angle redundancy detection is performed according to the motor angle change, so that the angle error during detection is reduced, the real-time detection of the rotation angle by the limited torque rotation angle motor is realized, and the detection precision of the motor position is effectively improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of motor angle measurement, and particularly relates to a method for redundant detection of the angle of a limited-rotation motor based on multiple angular displacement sensors. Background Art

[0002] A limited-rotation motor is a motor used for limited rotation within a specific range. It can accurately convert current into corresponding torque, achieve precise position control, and since the rotation angle range is limited, it does not require a complex feedback control system. Therefore, limited-rotation motors are commonly used in compact high-precision devices.

[0003] The angle measurement of traditional limited-rotation motors uses mechanical systems, potentiometers, or absolute position encoders. These methods have different disadvantages. Mechanical systems are easily affected by wear and contamination, the accuracy will decrease with the service time, and they are not suitable for high-frequency repeated measurements. Potentiometers are simple to use but are easily affected by noise interference and aging. Absolute position encoders are commonly used for high-precision requirements and have a high cost.

[0004] Currently, angular displacement sensors are often used to measure the rotation angle of the motor by detecting the magnetic field change of the permanent magnet on the rotor. This method has a low cost and is simple in design and implementation, but due to the fact that it can only detect one direction of the magnetic field and there is an installation accuracy, its measurement accuracy and resolution are relatively low. Summary of the Invention

[0005] In order to solve at least one of the above technical problems existing in the prior art, the present invention provides a method for redundant detection of the angle of a limited-rotation motor based on multiple angular displacement sensors.

[0006] The present invention is implemented by adopting the following technical solutions: A method for redundant detection of the angle of a limited-rotation motor based on multiple angular displacement sensors includes the following steps:

[0007] S1: Obtain the first voltage signal of the first angular displacement sensor and the second voltage signal of the second angular displacement sensor;

[0008] S2: Convert the first voltage signal and the second voltage signal into corresponding first digital signal and second digital signal;

[0009] S3: Perform signal processing on the first digital signal and the second digital signal, perform amplitude operation according to the signal processing result, perform amplitude compensation and zero-phase calibration through the amplitude operation result, and determine the first angle of the limited-rotation motor according to the amplitude compensation result and the zero-phase calibration result;

[0010] S4: Adjust the phase positions of the first angular displacement sensor and the second angular displacement sensor, re-collect the corresponding voltage signals, calculate the second angle of the limited rotation angle motor after the phase change based on the newly collected voltage signals, and perform motor angle redundancy detection based on the first angle and the second angle of the limited rotation angle motor.

[0011] Preferably, step S2 includes:

[0012] Amplify the first voltage signal and the second voltage signal through an amplifier circuit, then filter them through a low-pass filter, and finally perform signal conversion to obtain the corresponding first digital signal and second digital signal.

[0013] Preferably, step S3 includes:

[0014] Process the first digital signal and the second digital signal into corresponding function forms, then perform amplitude calculation and amplitude compensation;

[0015] Return the limited rotation angle motor to the zero position, calculate the phase error of the limited rotation angle motor, and perform zero position phase calibration;

[0016] Utilize the phase-locked loop principle and the PI algorithm to determine the angle of the limited rotation angle motor based on the amplitude compensation result and the zero position phase calibration result.

[0017] Preferably, processing the first digital signal and the second digital signal into corresponding function forms, and its function expression is:

[0018]

[0019] In the formula, A and B are the signal amplitudes corresponding to the first voltage signal and the second voltage signal respectively, θ is the motor angle of the limited rotation angle motor, and are the phase angle errors of the corresponding voltage signals respectively, and C and D are the signal amplitude errors.

[0020] Preferably, the formula for amplitude calculation and amplitude compensation is:

[0021]

[0022] In the formula, u' A and u' B are the amplitude compensation values of the corresponding voltage signals respectively.

[0023] Preferably, the formula for phase error calculation is:

[0024]

[0025] Preferably, a PWM wave with a gradually decreasing duty cycle is used to drive the limited-rotation angle motor to return to the zero position.

[0026] Preferably, it further includes: constructing an error compensation model and performing error processing through the error compensation model.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] The present invention discloses a method for redundant detection of the angle of a limited-rotation angle motor based on multiple angular displacement sensors. The redundant detection method is to use multiple angular displacement sensors to measure the change in physical quantities caused by the rotation of the rotor at the stator of the limited-rotation angle motor, so as to obtain the rotor angle, and achieve the redundant detection effect by changing the angle of the angular displacement sensors. The redundant detection method specifically includes determining the layout of the angular displacement sensors, and real-time detecting the voltage signals of two angular displacement sensors; processing the voltage signals output by the angular displacement sensors to convert them into digital signals; processing the obtained digital signals, performing amplitude compensation and zero-phase calibration on them, and calculating the current motor angle through algorithmic estimation; performing error processing, and using an error compensation algorithm to reduce errors. Compared with the prior art, the present invention has higher requirements for detection accuracy, solves the problems of single detection magnetic field direction and errors existing during installation, realizes the real-time detection of the rotation angle of the limited-torque rotation angle motor, and effectively improves the detection accuracy of the motor position. Description of the Drawings

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0030] Figure 1 It is a schematic flowchart of the method for redundant detection of the angle of a limited-rotation angle motor based on multiple angular displacement sensors provided by an embodiment of the present invention;

[0031] Figure 2 It is a block diagram of the rotor angle calculation process provided by an embodiment of the present invention;

[0032] Figure 3 It is a principle block diagram of an orthogonal phase-locked loop provided by an embodiment of the present invention;

[0033] Figure 4 It is a principle block diagram of a symmetric phase-locked loop provided by an embodiment of the present invention;

[0034] Figure 5 It is a layout diagram of angular displacement sensors (90° phase) when the rotor of the present invention embodiment has four permanent magnets;

[0035] Figure 6 Layout diagram of angular displacement sensors (180° phase) when the rotor of the embodiment of the present invention has four permanent magnets. Specific implementation manners

[0036] Combined with the accompanying drawings in the embodiments of the present invention, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation manners obtained by those of ordinary skill in the art without creative efforts belong to the scope protected by the present invention.

[0037] It should be noted that the structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those who are familiar with this technology to understand and read, and are not used to limit the limited conditions under which the present invention can be implemented. Therefore, they do not have a substantial technical meaning. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should fall within the scope covered by the technical content disclosed by the present invention. It should be noted that in this specification, relational terms such as first and second are only used to distinguish one entity from several other entities, and do not necessarily require or imply any actual relationship or order between these entities.

[0038] The present invention provides an embodiment:

[0039] As Figure 1 shown, a flowchart of a method for redundant detection of the angle of a limited-rotation motor based on multi-angular displacement sensors is provided, including the following steps:

[0040] S1: Obtain a first voltage signal of a first angular displacement sensor and a second voltage signal of a second angular displacement sensor;

[0041] S2: Convert the first voltage signal and the second voltage signal into corresponding first digital signal and second digital signal;

[0042] S3: Perform signal processing on the first digital signal and the second digital signal, perform amplitude operation according to the signal processing result, perform amplitude compensation and zero-phase calibration through the amplitude operation result, and determine the first angle of the limited-rotation motor according to the amplitude compensation result and the zero-phase calibration result;

[0043] S4: Adjust the phase positions of the first angular displacement sensor and the second angular displacement sensor, re-collect the corresponding voltage signals, calculate the second angle of the limited rotation angle motor after the phase change based on the newly collected voltage signals, and perform motor angle redundancy detection based on the first angle and the second angle of the limited rotation angle motor.

[0044] In this embodiment, Hall elements are selected for the first angular displacement sensor and the second angular displacement sensor, and the two sensors are arranged in a 90° phase layout. The specific layout is as Figure 5 shown. There are four permanent magnets on the rotor of the limited rotation angle motor, and the two angular displacement sensors are accurately arranged in a 90° phase around the rotor.

[0045] Optionally, step S2 includes: amplifying the first voltage signal and the second voltage signal through an amplifier circuit, then filtering through a low-pass filter, and finally performing signal conversion to obtain the corresponding first digital signal and second digital signal.

[0046] In this embodiment, an amplifier circuit is used to amplify the first voltage signal and the second voltage signal to enhance the signal strength of the corresponding voltage signals and reduce the influence of noise on the voltage signals. Then, a low-pass filter is used for filtering to reduce signal noise and interference, and the first voltage signal and the second voltage signal are converted into the corresponding first digital signal and second digital signal.

[0047] Optionally, step S3 includes: processing the first digital signal and the second digital signal into corresponding function forms, then performing amplitude calculation and amplitude compensation; returning the limited rotation angle motor to the zero position, calculating the phase error of the limited rotation angle motor, and performing zero position phase calibration; using the phase-locked loop principle and the PI algorithm to determine the angle of the limited rotation angle motor based on the amplitude compensation result and the zero position phase calibration result.

[0048] In this embodiment, as Figure 2 shown, a schematic flow chart for determining the angle of the limited rotation angle motor is provided. First, the first digital signal and the second digital signal are represented in function form, then amplitude calculation is performed, amplitude compensation is performed according to the amplitude calculation result, zero position phase calibration is performed according to the new signal after amplitude compensation to obtain the phase error, then the error of the motor rotor position and the rotor angle is calculated using the phase-locked loop principle, and finally the angle of the limited rotation angle motor is calculated based on the error of the motor rotor position and the rotor angle.

[0049] The detailed calculation process is as follows:

[0050] Specifically, let the two trigonometric function signals obtained after processing by the first angular displacement sensor and the second angular displacement sensor be A(t) and B(t) respectively. At this time, the first angular displacement sensor and the second angular displacement sensor are arranged with a 90° phase difference. Then:

[0051]

[0052] where A and B are the signal amplitudes corresponding to the first voltage signal and the second voltage signal respectively, θ is the motor angle of the limited rotation angle motor, and are the phase angle errors of the corresponding voltage signals respectively, and C and D are the signal amplitude errors.

[0053] Perform amplitude operation to achieve amplitude compensation. Specifically, represent the amplitude compensation value of the trigonometric function as:

[0054]

[0055] where u Amax and u Amin are the maximum signal amplitude and the minimum signal amplitude corresponding to the first voltage signal respectively, u Bmax and u Bmin are the maximum signal amplitude and the minimum signal amplitude corresponding to the second voltage signal respectively, and τ is the amplitude ratio.

[0056] According to the above expression of the amplitude compensation value, convert u A and u B into:

[0057]

[0058]

[0059] Use a PWM wave with a gradually decreasing duty cycle to drive the limited rotation angle motor to return to the 0 position. At this time, θ in u' A and u' B is 0.

[0060] Then, assume that the values at the intersection with the θ = 0 axis at this time are U A and U B , and the following can be obtained:

[0061]

[0062] The phase error when installing the first angular displacement sensor and the second angular displacement sensor is obtained as:

[0063]

[0064] According to Figure 3The schematic diagram of the principle of the quadrature phase-locked loop is shown. The process of calculating the angle of the limited rotation angle motor using the quadrature phase-locked loop principle can be expressed as follows:

[0065] e = sinθcosθ′ - cosθsinθ′

[0066]

[0067] where e is the angle error of the limited rotation angle motor, is the corresponding motor speed, k p is the proportionality coefficient, mod is the modulo operation, k i is the integral coefficient, and θ′ is the position of the electronic rotor.

[0068] Through the PI (Proportional-Integral) regulator, the angle error of the limited rotation angle motor is adjusted to 0. At this time, θ′ and θ are equal, but when the phase is non-orthogonal, there will be a certain error between θ′ and θ.

[0069] According to the quadrature phase-locked loop principle and the PI algorithm, the motor rotation angle is obtained, and then the error Δθ of the compensated rotor angle is calculated according to the non-orthogonal error that appears when calculating θ′θ′ γ .

[0070] Specifically, the non-orthogonality causes an error of a direct current and a double fundamental frequency in the calculated motor rotation angle position, that is:

[0071]

[0072]

[0073] In this embodiment, the Δθ in the cosine function is ignored γ , and the following is obtained:

[0074]

[0075] Combining the above formulas, the compensated angle of the limited rotation angle motor is determined as:

[0076]

[0077] In this embodiment, as Figure 6 shown, the layout of the first angular displacement sensor and the second angular displacement sensor is adjusted, and the two angular displacement sensors are adjusted to a phase difference of 180°.

[0078] The corresponding voltage signals at this time are respectively:

[0079]

[0080] where, and are the corresponding phase angle errors respectively, and θ is the angle of the limited rotation motor.

[0081] In this embodiment, the solving process of the phase error during installation is the same as that of solving the phase error at 90° phase. Therefore, according to the foregoing calculation process, the installation phase error when the phase difference is 180° is:

[0082]

[0083] In this embodiment, as Figure 4 shown is the principle block diagram of the symmetric phase-locked loop used when the phase difference is 180°. Its position calculation principle and process can be expressed as:

[0084] e = sin 2 θ - sin 2 θ′

[0085]

[0086] Then, using the phase-locked loop principle and the PI algorithm, estimate the asymmetric error Δθ for compensation when asymmetry occurs γ2 , and obtain the corresponding motor rotor angle after compensation:

[0087]

[0088] Perform redundant detection based on the motor rotor angles obtained when the first angular displacement sensor and the second angular displacement sensor are at 90° phase and 180° phase respectively.

[0089] Optionally, it further includes: constructing an error compensation model and performing error processing through the error compensation model.

[0090] In this embodiment, by collecting error data under different conditions, an error compensation model is established, and this model is applied to compensate the corresponding errors. In practical applications, the established error compensation model includes data collection, and the established error compensation model is trained and optimized. The compensated errors include temperature error and nonlinear error.

[0091] The embodiment of the present invention provides a rotor layout of four permanent magnets as shown in Figure 5 , Figure 6 shown. It can also be applied to other magnetic field structures, or similar motor and rotating part angle detections. The present invention is not limited thereto.

[0092] The present invention discloses a method for redundant detection of the angle of a limited-rotation motor based on a multi-angle displacement sensor. The redundant detection method is to use the multi-angle displacement sensor to measure the change in physical quantity caused by the rotation of the rotor at the stator of the limited-rotation motor, so as to obtain the rotor angle, and achieve the redundant detection effect by changing the angle of the angle displacement sensor. The specific steps of the redundant detection method include determining the layout of the angle displacement sensors and detecting the voltage signals of two angle displacement sensors in real time; processing the voltage signals output by the angle displacement sensors to convert them into digital signals; processing the obtained digital signals, performing amplitude compensation and zero-phase calibration on them, and calculating the current motor angle through algorithmic estimation; and performing error processing and using an error compensation algorithm to reduce errors. Compared with the prior art, the present invention has higher requirements for detection accuracy, solves the problems of single magnetic field direction detection and installation errors, realizes the real-time detection of the rotation angle of the limited-torque rotation motor, and effectively improves the detection accuracy of the motor position.

[0093] As described above, the above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A method for redundant detection of the angle of a limited-rotation motor based on a multi-angle displacement sensor, characterized in that It includes the following steps: S1: Obtain the first voltage signal of the first angular displacement sensor and the second voltage signal of the second angular displacement sensor; S2: Convert the first voltage signal and the second voltage signal into corresponding first digital signal and second digital signal; S3: Process the first digital signal and the second digital signal, perform amplitude operation according to the signal processing result, perform amplitude compensation and zero-phase calibration through the amplitude operation result, and determine the first angle of the limited rotation angle motor according to the amplitude compensation result and the zero-phase calibration result; S4: Adjust the phase positions of the first angular displacement sensor and the second angular displacement sensor, re-collect the corresponding voltage signals, calculate the second angle of the limited rotation angle motor after phase change according to the newly collected voltage signals, and perform motor angle redundancy detection according to the first angle of the limited rotation angle motor and the second angle of the limited rotation angle motor.

2. The method for redundant detection of the angle of a limited rotation motor based on a multi-angle displacement sensor according to claim 1, characterized in that Step S2 includes: Amplify the first voltage signal and the second voltage signal through an amplifier circuit, then filter through a low-pass filter, and finally perform signal conversion to obtain the corresponding first digital signal and second digital signal.

3. The method for detecting the angle redundancy of a limited rotation angle motor based on a multi-angle displacement sensor according to claim 1, wherein Step S3 includes: Process the first digital signal and the second digital signal into corresponding function forms, then perform amplitude operation, and perform amplitude compensation; Return the limited rotation angle motor to the zero position, calculate the phase error of the limited rotation angle motor, and perform zero-phase calibration; Determine the angle of the limited rotation angle motor based on the amplitude compensation result and the zero-phase calibration result using the phase-locked loop principle and the PI algorithm.

4. The method for redundant detection of the angle of a limited rotation motor based on a multi-angle displacement sensor according to claim 3, characterized in that The processing of the first digital signal and the second digital signal into corresponding function forms has the following function expression: Where A and B are the signal amplitudes corresponding to the first voltage signal and the second voltage signal respectively, and θ is the motor angle of the limited rotation angle motor, and are the phase angle errors of the corresponding voltage signals respectively, and C and D are the signal amplitude errors.

5. The method for detecting the angle redundancy of a limited rotation angle motor based on a multi-angle displacement sensor according to claim 3, characterized in that, The formula for performing amplitude operation and performing amplitude compensation is: where u' A and u' B are the amplitude compensation values of the corresponding voltage signals, respectively.

6. The method for detecting the angular redundancy of a limited rotation angle motor based on a multi-angle displacement sensor according to claim 3, wherein The formula for calculating the phase error is: where U A is the value of the first intersection point of θ with the 0 axis, and U B is the value of the second intersection point of θ with the 0 axis.

7. The method for detecting the angle redundancy of a limited-rotation motor based on a multi-angle displacement sensor according to claim 3, wherein Drive the limited rotation angle motor to return to the zero position using a PWM wave with a gradually decreasing duty cycle.

8. The method for finite rotation angle motor angle redundancy detection based on a multi-angle displacement sensor according to claim 1, wherein It also includes: Construct an error compensation model and perform error processing through the error compensation model.

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