An encoder device based on linear hall sensors and a fault-tolerant control method

Abstract

The application discloses an encoder device based on linear Hall sensors, comprising a linear Hall sensor module, a signal analysis module and a magnetic ring module; the linear Hall sensor module comprises four linear Hall sensors, and adjacent two linear Hall sensors are distributed at a 90-degree included angle; the linear Hall sensors are used for acquiring the intensity of a magnetic field in the magnetic ring module; the signal analysis module is connected with the linear Hall sensor module, and is used for processing the electric signal output by the linear Hall sensors and obtaining an angle; and the magnetic ring module is sleeved on a rotor and is used for generating a magnetic field which changes with the electric signal. Different fault control methods are adopted for different damage problems, so that the efficiency is improved, and the stability of the motor is ensured.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of permanent magnet synchronous motors, in particular to an encoder device based on linear Hall sensors and a fault-tolerant control method. BACKGROUND

[0002] An encoder is a device that encodes or converts signals or data into a signal form that can be used for communication, transmission and storage. The encoder can convert angular displacement or linear displacement into an electrical signal, so the encoder is widely used in the fields of measurement, automation, computers and information technology.

[0003] A traditional encoder usually obtains absolute position by a mechanical method, and converts mechanical geometric displacement on an output shaft into pulses and digital quantities through a grating and photoelectric conversion. However, the precision of this method is not high, and it is seriously affected in a large range and in a harsh environment. In addition, wear caused by long-time contact leads to deviation, and also causes certain light pollution. Secondly, according to the Hall effect, the encoder generates four sinusoidal waves with a phase difference of 90 degrees through four orthogonal Hall devices, and obtains information by analyzing the waveforms. However, electromagnetic interference and temperature changes can cause position deviation, thereby causing errors.

[0004] The application provides an encoder device based on linear Hall sensors and a fault-tolerant control method, which selects different angle calculation methods according to different states of the Hall device, and provides accurate rotor position for the motor. SUMMARY

[0005] The application provides an encoder device based on linear Hall sensors and a fault-tolerant control method, which solves the problem of deviation caused by errors of the Hall sensor in the traditional encoder.

[0006] The application provides an encoder device based on linear Hall sensors, which comprises a linear Hall sensor module, a signal analysis module and a magnetic ring module.

[0007] The linear Hall sensor module comprises four linear Hall sensors, and adjacent two linear Hall sensors are distributed at an angle of 90 degrees. The linear Hall sensor is used to obtain the strength of the magnetic field in the magnetic ring module.

[0008] The signal analysis module is connected with the linear Hall sensor module, and is used to process the electrical signal output by the linear Hall sensor and obtain an angle.

[0009] The magnetic ring module is sleeved on the rotor, and is used to generate a magnetic field that changes with the electrical signal.

[0010] The application further provides an encoder device fault-tolerant control method based on linear Hall sensors, comprising the following steps:

[0011] Step 1: obtaining the output waveform of the four linear Hall sensors, and obtaining the phase difference and amplitude difference between the four linear Hall sensors according to the output waveform;

[0012] Step 2: judging the error type of the linear Hall sensors according to the phase difference and amplitude difference;

[0013] Step 3: selecting different angle calculation methods according to different error types; obtaining at least one angle as the output angle of the encoder to adjust the rotation angle of the motor, so that the motor rotates smoothly.

[0014] Further, the error types in step 2 include:

[0015] Error type 1: one linear Hall sensor is damaged; error type 2: two opposite linear Hall sensors are damaged; error type 3: two adjacent linear Hall sensors are damaged; error type 4: three linear Hall sensors are damaged; and error type 5: all four linear Hall sensors are damaged.

[0016] Further, the judgment method of the error type 1 is:

[0017] When there is only one output phase difference of 90°, it is error type 1;

[0018] The judgment method of the error type 2 is:

[0019] When there is no output phase difference of 90°, and the output phase difference of the opposite linear Hall sensor is 180°, it is error type 2;

[0020] The judgment method of the error type 3 is:

[0021] When there is only one output phase difference of 90°, and the output phase difference of the opposite linear Hall sensor is not 180°, it is error type 3;

[0022] The judgment method of the error type 4 is:

[0023] When there is no output phase difference of 90°, and the output phase difference of the opposite linear Hall sensor is not 180°, it is error type 4;

[0024] The judgment method of the error type 5 is:

[0025] When there is no output, it is judged as error type 5.

[0026] Further, the specific method of error compensation according to different error types in step 3 is as follows:

[0027] When it is error type 1, two sets of orthogonal signals are taken from the output signals of the remaining three linear Hall sensors, two angles are calculated by using the quadrature phase-locked loop calculation method, and the arithmetic mean of the two angles is taken as the accurate angle;

[0028] When it is error type 2, the amplitude information of the output signals of the remaining two linear Hall sensors is compensated with each other, one angle is obtained by using the direct calculation method, and the obtained angle is taken as the accurate angle;

[0029] When it is error type 3, the remaining two mutually orthogonal Hall signals are calculated by using the quadrature phase-locked loop calculation method to obtain one angle, and the obtained angle is taken as the accurate angle;

[0030] When it is error type 4, the output signal of the remaining one linear Hall sensor is used, one angle is obtained by using the direct calculation method, and the obtained angle is taken as the accurate angle.

[0031] Further, the quadrature phase-locked loop calculation method is as follows:

[0032]

[0033] x β (t)=A sinω0t

[0034]

[0035]

[0036] wherein, x β (t) is the measurement signal of the quadrature linear Hall sensor, ω0 is the frequency of the measurement signal, A is the amplitude of the measurement signal, and ε(t) is the phase detection output, is the angular frequency of the measurement signal after quadrature phase-locked loop processing, is the angular position of the measurement signal after quadrature phase-locked loop processing.

[0037] Further, the direct calculation method is as follows:

[0038]

[0039]

[0040]

[0041]

[0042] Wherein, A is the amplitude of the linear Hall sensor output signal, K is the offset of the linear Hall sensor output signal, x(t) is the current value of the linear Hall sensor output signal, The final measured signal is obtained.

[0043] The beneficial effects of the present application are:

[0044] 1. The present application does not involve hardware disassembly, and has no special requirements for the installation precision of the linear Hall sensor, reducing the operation difficulty during installation.

[0045] 2. The present application reduces mechanical contact and increases the life of the encoder.

[0046] 3. The linear Hall sensor used in the present application has high precision and low cost.

[0047] 4. The present application uses different fault-tolerant control methods for different damage problems to improve efficiency and ensure the stability of the motor. BRIEF DESCRIPTION OF DRAWINGS

[0048] The features and advantages of the present application will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the present application, in which:

[0049] Figure 1 The present application is based on a linear Hall sensor device schematic diagram;

[0050] Figure 2 The present application is based on a linear Hall sensor encoder fault-tolerant control method flow chart. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0052] As shown in Figure 1 , 2 The present application provides a linear Hall sensor-based encoder device, comprising: a linear Hall sensor module, a signal analysis module, and a magnetic ring module.

[0053] The linear Hall sensor module includes four linear Hall sensors, as Figure 1As shown, H1, H2, H3, H4 are linear Hall sensors, H1 and H3, H2 and H4 are installed at opposite positions with a magnetic ring as the center, H1 and H2, H2 and H3, H3 and H4, H4 and H1 have a mutual orthogonal position relationship, the magnetic ring module is installed axially with the motor rotor shaft, and is in the same horizontal plane with the linear Hall module, the linear Hall sensor is used to obtain the strength of the magnetic field in the magnetic ring module;

[0054] The signal analysis module is connected with the linear Hall sensor module, and the signal analysis module is used for processing the electric signal output by the linear Hall sensor;

[0055] The magnetic ring module is sleeved on the rotor, and the magnetic ring module is used to generate a magnetic field that changes with the electric signal.

[0056] The application also provides a kind of encoder device fault-tolerant control method based on linear Hall sensor, including the following steps:

[0057] Step 1: obtain the output waveform of four linear Hall sensors, and obtain the phase difference and amplitude difference between the four linear Hall sensors according to the output waveform;

[0058] Step 2: determine the error type of the linear Hall sensor according to the phase difference and amplitude difference;

[0059] Wherein, the error type includes: error type 1: one linear Hall sensor is damaged; error type 2: two opposite linear Hall sensors are damaged; error type 3: two adjacent linear Hall sensors are damaged; error type 4: three linear Hall sensors are damaged; error type 5: four linear Hall sensors are damaged;

[0060] Each error type determination method is as follows:

[0061] The error type 1 determination method is as follows:

[0062] When there are only two output phase differences of 90°, it is error type 1;

[0063] The error type 2 determination method is as follows:

[0064] When there is no output phase difference of 90°, and the output phase difference of the opposite linear Hall sensor is 180°, it is error type 2;

[0065] The error type 3 determination method is as follows:

[0066] When there is only one output phase difference of 90°, and the output phase difference of the opposite linear Hall sensor is not 180°, it is error type 3;

[0067] The error type 4 determination method is as follows:

[0068] When there is no output phase difference of 90°, and the output phase difference of the relative linear Hall sensor is not 180°, it is error type 4;

[0069] The judgment method of error type 5 is:

[0070] When there is no output, it is judged as error type 5;

[0071] In addition to the five error types, there is a normal type:

[0072] Four linear Hall sensors are not damaged, that is, the phase difference of the four output waveforms is 90°;

[0073] Step 3: Select different angle calculation methods according to different error types; obtain the accurate angle according to one or several angles calculated, adjust the motor angle, and make the motor rotate smoothly, as follows:

[0074] When it is error type 1, take two sets of orthogonal signals in the output signals of the remaining three linear Hall sensors, and use the quadrature phase-locked loop calculation method to calculate two angles, and take the arithmetic mean of the two angles as the accurate angle;

[0075] When it is error type 2, the amplitude information of the output signals of the remaining two linear Hall sensors is compensated, and an angle is obtained by direct calculation method, and the obtained angle is used as the accurate angle for error compensation;

[0076] When it is error type 3, the remaining two mutually orthogonal Hall signals are calculated by using the quadrature phase-locked loop calculation method to obtain an angle, and the obtained angle is used as the accurate angle;

[0077] When it is error type 4, the output signal of the remaining one linear Hall sensor is used, and an angle is obtained by direct calculation method, and the obtained angle is used as the accurate angle;

[0078] When it is error type 5, output a fault signal;

[0079] When it is a normal type, in the output of the four linear Hall sensors, four sets of two-by-two orthogonal output signals are calculated by using the quadrature phase-locked loop calculation method to obtain four angles, and the four angles are the accurate angles.

[0080] Among them, the quadrature phase-locked loop calculation method is:

[0081]

[0082] x β (t)=A sinω0t

[0083]

[0084]

[0085] wherein, x β (t) is the measurement signal of the quadrature linear Hall sensor, ω0 is the frequency of the measurement signal, A is the amplitude of the measurement signal, and ε(t) is the phase discrimination output, is the angular frequency of the measurement signal after quadrature phase-locked loop processing, is the angular position of the measurement signal after quadrature phase-locked loop processing.

[0086] The direct calculation method is:

[0087]

[0088]

[0089]

[0090]

[0091] wherein, A is the amplitude of the linear Hall sensor output signal, K is the offset of the linear Hall sensor output signal, and x(t) is the current value of the linear Hall sensor output signal, is the final obtained angular position of the measurement signal;

[0092] Step 4: feedback the error compensation signal to the phase-locked loop, adjust the motor coefficient, and make the motor rotate smoothly.

[0093] Although the embodiments of the present application are described in conjunction with the drawings, various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and changes fall within the scope defined by the appended claims.

Claims

1. A fault-tolerant control method of a linear Hall sensor-based encoder device, wherein, The linear Hall sensor-based encoder device comprises a linear Hall sensor module, a signal analysis module, and a magnetic ring module. The linear Hall sensor module comprises four linear Hall sensors, and adjacent two linear Hall sensors are distributed at an angle of 90°. The signal analysis module is connected to the linear Hall sensor module, and is configured to process the electrical signals output by the linear Hall sensors and obtain an angle. The magnetic ring module is sleeved on a rotor, and is configured to generate a magnetic field that changes with the electrical signals. The fault-tolerant control method of the linear Hall sensor-based encoder device comprises the following steps: Step 1: obtaining the output waveforms of the four linear Hall sensors, and obtaining the phase difference and amplitude difference between the four linear Hall sensors according to the output waveforms; Step 2: determining the error type of the linear Hall sensors according to the phase difference and amplitude difference, wherein the error type comprises: Error type 1: one linear Hall sensor is damaged; Error type 2: two opposite linear Hall sensors are damaged; Error type 3: two adjacent linear Hall sensors are damaged; Error type 4: three linear Hall sensors are damaged; Error type 5: all four linear Hall sensors are damaged; Step 3: selecting different angle calculation methods according to different error types, and obtaining at least one angle as the output angle of the encoder to adjust the rotation angle of the motor and make the motor rotate smoothly, and the specific method is as follows:

2. The linear Hall sensor based encoder device fault-tolerant control method of claim 1, wherein, When the error type is error type 1, two sets of orthogonal signals are taken from the output signals of the remaining three linear Hall sensors, and two angles are calculated by using the quadrature phase-locked loop calculation method, and the arithmetic mean of the two angles is taken as the accurate angle; When the error type is error type 2, the amplitude information of the output signals of the remaining two linear Hall sensors is compensated, and one angle is obtained by using the direct calculation method, and the obtained angle is taken as the accurate angle; When the error type is error type 3, one angle is calculated by using the quadrature phase-locked loop calculation method, and the obtained angle is taken as the accurate angle; When the error type is error type 4, one angle is obtained by using the direct calculation method, and the obtained angle is taken as the accurate angle. The judgment method of error type 1 is as follows: When there are only two output phase differences of 90°, it is error type 1; The judgment method of error type 2 is as follows: When there is no output phase difference of 90°, and the output phase difference of the opposite linear Hall sensor is 180°, it is error type 2; The judgment method of error type 3 is as follows: When there is only one output phase difference of 90°, and the output phase difference of the opposite linear Hall sensor is not 180°, it is error type 3; The judgment method of error type 4 is as follows: When there is no output phase difference of 90°, and the output phase difference of the opposite linear Hall sensor is not 180°, it is error type 4; The judgment method of error type 5 is as follows: When there is no output, it is judged as error type 5.

3. The linear Hall sensor based encoder device fault-tolerant control method of claim 1, wherein, The calculation method of the quadrature phase-locked loop is: ； ； ； ； wherein , is a measurement signal of a quadrature linear Hall sensor, is a frequency of the measurement signal, A is an amplitude of the measurement signal, is a phase-detect output, is an angular frequency of the measurement signal after quadrature phase-locked loop processing, is an angular position of the measurement signal after quadrature phase-locked loop processing.

4. The linear Hall sensor based encoder device fault-tolerant control method of claim 1, wherein, The direct calculation method is: ； ； ； ； where A is the amplitude of the linear Hall sensor output signal, K is the offset of the linear Hall sensor output signal, is the current value of the linear Hall sensor output signal, is the final determined angular position of the measurement signal.

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