Disconnection detection system and angle compensation method of rotary transformer

Abstract

The invention discloses a broken line detection system and angle compensation method for a rotary transformer, and the system is characterized in that the system comprises an amplification module, a filtering module, a signal conditioning module and a detection module, and the amplification module and the filtering module are used for amplifying and filtering an output signal of the rotary transformer; the signal conditioning module generates a detection signal according to the filtered differential signal, and the detection module obtains a broken line detection result and an angle compensation method based on the broken line detection result according to the detection signal; the method has the advantages that a hardware circuit is simple in structure, low in cost and fast in response to disconnection of the rotary transformer, errors between a mechanical angle estimated by a software level during disconnection and an actual mechanical angle of the rotary transformer can be eliminated after angle compensation, and normal operation of a motor is guaranteed; and meanwhile, the current of the driver cannot generate large fluctuation in the whole disconnection time.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of motor control, and in particular to a broken wire detection system and angle compensation method for a resolver. BACKGROUND

[0002] A resolver, short for resolver, is an electromechanical position sensor that measures rotational angle or speed using electromagnetic induction principles. It is widely used in high-precision position detection in harsh environments due to its non-contact, high reliability, and strong anti-interference characteristics. In the industrial motion control field, servo systems have strict requirements for encoder signal integrity. However, during motor operation, the motor driver may cause encoder signal interruption due to wire harness or connector breakage. Breakage usually refers to the interruption or failure of connections in sensor or control signal lines, resulting in abnormal or complete disappearance of encoder signals, which may directly affect the operation of the motor and even cause system loss of control.

[0003] Chinese patent CN117008010A discloses a resolver break detection circuit. In the technical solution, whether a break occurs is determined by detecting whether the difference between the feedback signal and the single-ended circuit output signal value is less than 0V. This solution requires a power supply system for the operational amplifier to include positive and negative power supplies, or a rail-to-rail operational amplifier to output 0V in a single power supply system. This has great limitations for power supply design and operational amplifier selection.

[0004] Currently, after detecting the break of the resolver output signal, the following control methods are commonly used:

[0005] (1) Safe shutdown. This method is the most commonly used safety control strategy. Once the controller detects a resolver fault, it immediately stops PWM output and turns off the inverter. The motor gradually stops rotating under the resistance of the load. This method is suitable for high safety requirements such as elevators and large industrial robots, but not for continuous rotation of the motor.

[0006] (2) Degraded operation. This method can control the motor to continue running in open-loop mode for a short time. The advantages are that the system does not immediately shut down, allowing some time to complete the current task or move to a safe position. The disadvantages are that the control accuracy drifts over time, the estimated angle gradually deviates from the actual angle due to the lack of feedback, the torque control ability is poor, which may cause loss of synchronization or overcurrent, and it can only be maintained for a very short time (a few seconds to tens of seconds), and usually requires reducing speed and torque (de-rating operation).

[0007] (3) Switch to sensorless observer control mode. This method can maintain the motor to continue running at high performance for a long time, realize seamless switching control, but the disadvantage is that the algorithm is extremely complex and requires high processor performance. SUMMARY

[0008] The technical problem to be solved by the present application is to provide a simple structure, which can quickly and accurately detect whether the output signal of the resolver is disconnected, and an angle compensation method, so that the motor can work stably and the speed will not jump greatly to cause error shutdown.

[0009] The technical solution adopted by the present application to solve the above technical problems is: a resolver disconnection detection system, comprising an amplification module, a filtering module, a signal conditioning module and a detection module, the amplification module is used for amplifying a pair of differential signals output by the resolver, the filtering module filters the amplified differential signals, the signal conditioning module is used for generating a detection signal according to the filtered differential signals, and the detection module is used for obtaining a disconnection detection result according to the detection signal.

[0010] The signal conditioning module comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor and an operational amplifier, one end of the first resistor, one end of the second resistor and one end of the fourth resistor are connected and used for receiving a positive differential signal in the filtered differential signal, the other end of the first resistor is grounded, the other end of the fourth resistor and one end of the fifth resistor are connected and used for receiving a negative differential signal in the filtered differential signal, the other end of the second resistor, one end of the third resistor and the inverting voltage input end of the operational amplifier are connected, the other end of the fifth resistor, one end of the sixth resistor and the non-inverting voltage input end of the operational amplifier are connected, the other end of the sixth resistor is connected to a DC bias voltage signal, and the other end of the third resistor and the output end of the operational amplifier are connected and output the detection signal.

[0011] Compared with the prior art, the application has the advantages that the signal conditioning module generates a detection signal according to the positive differential signal, the negative differential signal and the DC bias voltage signal in the filtered differential signal; the detection module obtains a wire break detection result according to the detection signal, so as to facilitate timely response processing of the wire break condition of the input signal and the output signal of the resolver; wherein the input signal of the resolver is a pair of excitation signals, the resolver outputs a pair of sine differential signals and a pair of cosine differential signals, the sine differential signal corresponds to a wire break detection system, the cosine differential signal corresponds to another wire break detection system, the circuit structures and principles in the two wire break detection systems are basically the same, so when the pair of output sine differential signals and the pair of output cosine differential signals are detected to occur wire break at the same time, it is judged that the input signal of the resolver occurs wire break; a conventional response processing method such as immediately generating a fault signal, triggering system safety shutdown, and reporting the specific fault type, facilitates timely maintenance; or keeping the last reliable position value and outputting an invalid position signal, the system can control the motor to slow down based on the invalid position value according to a preset parking curve, instead of losing all control at once; the circuit structure of the signal conditioning module is relatively simple, by setting the resistance between the differential signal input end in the original signal conditioning module and the operational amplifier, introducing the DC bias voltage signal and setting the corresponding resistance, the output detection signal can be used to accurately reflect the wire break condition of the resolver, and the operational amplifier can be selected to be powered by a common single power supply, the scheme has high implementation feasibility, the overall circuit structure is simple, and the cost is low.

[0012] Specifically, the detection module comprises an AD conversion module and a result judging module, the AD conversion module converts the detection signal into a digital signal and sends it to the result judging module, the result judging module samples the peak voltage value and the trough voltage value of the digital signal, obtains the average value of the sum of the peak voltage value and the trough voltage value of the digital signal and takes it as the final detection result; the result judging module is provided with a broken line judging voltage value and a normal judging voltage value, if the final detection result is equal to the broken line judging voltage value, the result judging module generates a broken line result judging signal; if the final detection result is equal to the normal judging voltage value, the result judging module generates a normal result judging signal. Due to the circuit structure design of the signal conditioning module, the voltage values of each part can be obtained according to the voltage value of a pair of input differential signals and the direct current bias voltage signal, the voltage of the detection signal is related to the difference between the positive differential signal and the negative differential signal in the filtered differential signal and the ratio of the third resistor to the second resistor. The average value of the sum of the peak voltage value and the trough voltage value of the digital signal is taken as the final detection result, under normal conditions, the voltage of the final detection result is equal to the direct current bias voltage signal; when the broken line occurs in the resolver output signal, the detection voltage value is only related to the first resistor, the second resistor, the third resistor in the signal conditioning module and the direct current bias voltage signal and outputs a fixed voltage, so that it can be detected and compared and taken as the broken line judging basis, and is independent of the voltage of the filtered differential signal input into the signal conditioning module.

[0013] Preferably, in the signal conditioning module, the resistance value r2 of the second resistor and the resistance value r5 of the fifth resistor satisfy: r2=r5, the resistance value r3 of the third resistor and the resistance value r6 of the sixth resistor satisfy: r3=r6, the resistance value r1 of the first resistor and the resistance value r4 of the fourth resistor satisfy: r1=r4, and the direct current bias voltage signal V R =1.65V, at this time, the normal judging voltage value V 正常 =V R =1.65V. At this time, the broken line judging voltage value has different results according to the different organizations of each resistor, but can also be directly calculated according to the resistance values of each resistor.

[0014] Further, in the signal conditioning module, the resistance value r2 of the second resistor and the resistance value r5 of the fifth resistor satisfy: r2=r5=5.99KΩ, the resistance value r3 of the third resistor and the resistance value r6 of the sixth resistor satisfy: r3=r6=10KΩ, the resistance value r1 of the first resistor and the resistance value r4 of the fourth resistor satisfy: r1=r4=10KΩ, and the direct current bias voltage signal V R =1.65V, at this time, the normal judging voltage value V 正常= V R = 1.65V, the broken line judgment voltage value V 断 = 2.09V.

[0015] The angle compensation method of the broken line detection system using the above-mentioned resolver comprises the following steps:

[0016] P1, a decoding control module, an angle compensation module and an error reporting module are set, the decoding control module is internally provided with a broken line event record module for generating a broken line event record value, the angle compensation module receives a broken line result determination signal or a normal result determination signal generated by the result determination module, when the angle compensation module receives the normal result determination signal and the broken line event record value of the broken line event record module is zero, the decoding control module is used to control the decoding module of the external motor control system to normally decode the detection signal output by the signal conditioning module; when the angle compensation module receives the broken line result determination signal, the decoding control module is used to control the decoding module to pause the decoding process, the first angle θ1 decoded by the decoding module at the time of broken line is recorded by the angle compensation module, and the angle compensation module sends a broken line state signal to the speed control module in the external motor control system, after receiving the broken line state signal, the speed control module controls the motor to continue running at the average speed v1 at the current time in an open-loop mode, at the same time, the broken line event record module sets the broken line event record value to 1 and starts counting at a fixed counting period, and step P2 is executed;

[0017] P2, the broken line event record module sets a maximum broken line counting threshold, when the counting value of the broken line event record module exceeds the set maximum broken line counting threshold, the broken line event record module generates an error reporting signal and sends it to the error reporting module to generate corresponding error information; if the angle compensation module has received the normal result determination signal before the counting value of the broken line event record module reaches the maximum broken line counting threshold, the broken line event record module clears the counting value and sets the broken line event record value to zero, the angle compensation module obtains the total rotation angle θ2 of the resolver in the time period from the time T1 when the broken line result determination signal is received to the time T2 when the normal result determination signal is received, θ2 = v1 × t1, and then step P3 is executed;

[0018] P3, at the time T2, the decoding control module is used to control the decoding module to restart the decoding process and obtain the second angle θ3 at the time T2;

[0019] P4, the angle compensation module obtains a compensation angle θ4, θ4 = mod(θ3-θ1-θ2, 360°), wherein mod is a modulus function;

[0020] P5, the speed control module takes the sum of θ4 and a preset angle increment θ5 of the next control period at T2 as a new angle increment, continues to control the motor to rotate, and the new angle increment θ6 satisfies: θ6=θ4+θ5.

[0021] The above angle compensation method mainly keeps the current motion state of the motor unchanged after detecting that the wire breakage occurs until the signal of the rotary transformer returns to normal; after detecting that the signal returns to normal, the error between the estimated position and the actual position of the rotary transformer is calculated and compensated, and is used as a compensation amount to compensate in the next control period after returning to normal, and the subsequent control periods return to normal control, so that the error between the estimated mechanical angle and the actual mechanical angle of the rotary transformer at the software level during the wire breakage can be eliminated, and the motor can continue to operate normally; at the same time, the current of the driver can be prevented from generating large fluctuations during the entire wire breakage time. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 The system principle block diagram in the embodiment one of the application;

[0023] Figure 2 The circuit principle diagram of the signal conditioning module in the embodiment one of the application;

[0024] Figure 3 The module principle block diagram used in the angle compensation method in the embodiment two of the application;

[0025] Figure 4 The collection diagram of each detection waveform corresponding to the test method proposed in the embodiment of the application. DETAILED DESCRIPTION

[0026] The application will be further described in detail below with reference to the embodiments of the drawings.

[0027] Embodiment one: as shown in Figure 1 , Figure 2 A wire breakage detection system of a rotary transformer, including an amplification module 2, a filter module 3, a signal conditioning module 4 and a detection module 5, the amplification module 2 is used for amplifying a pair of differential signals output by the rotary transformer 1, the filter module 3 filters the amplified differential signals, the signal conditioning module 4 is used for generating a detection signal according to the filtered differential signals, and the detection module 5 is used for obtaining a wire breakage detection result according to the detection signal.

[0028] The signal conditioning module 4 comprises a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6 and an operational amplifier U1A, one end of the first resistor R1, one end of the second resistor R2 and one end of the fourth resistor R4 are connected and used for receiving a positive differential signal in the filtered differential signal, the other end of the first resistor R1 is grounded, the other end of the fourth resistor R4 and one end of the fifth resistor R5 are connected and used for receiving a negative differential signal in the filtered differential signal, the other end of the second resistor R2, one end of the third resistor R3 and an inverting voltage input end of the operational amplifier U1A are connected, the other end of the fifth resistor R5, one end of the sixth resistor R6 and a non-inverting voltage input end of the operational amplifier U1A are connected, the other end of the sixth resistor R6 is connected to a direct current bias voltage signal, and the other end of the third resistor R3 is connected to an output end of the operational amplifier U1A and outputs a detection signal. The scheme utilizes a PWM output module in a common master control chip to output a square wave signal with a duty cycle of 50% and a working frequency of 8 kHz to generate a sine excitation signal, and each resistor in the signal conditioning module 4 is selected from common resistance values.

[0029] The detection module 5 comprises an AD conversion module 51 and a result determination module 52, the AD conversion module 51 converts the detection signal into a digital signal and sends it to the result determination module 52, the result determination module 52 samples a peak voltage value and a trough voltage value of the digital signal, obtains an average value of a sum of the peak voltage value and the trough voltage value of the digital signal and takes it as a final detection result, sets a broken line judgment voltage value and a normal judgment voltage value in the result determination module 52, if the final detection result is equal to the broken line judgment voltage value, the result determination module 52 generates a broken line result determination signal, and if the final detection result is equal to the normal judgment voltage value, the result determination module 52 generates a normal result determination signal. The detection module specifically adopts a DSP chip with a model number of TMS320F28377, and other DSP chips with similar functions can also be adopted to realize it.

[0030] As shown in Figure 2 VR is a direct current bias voltage signal, the signal conditioning circuit outputs a detection signal SIN, V1 represents a voltage at one end of the fourth resistor R4, V2 represents a voltage at the other end of the fourth resistor R4, Vn represents a voltage at an inverting voltage input end of the operational amplifier U1A, Vp represents a voltage at a non-inverting voltage input end of the operational amplifier U1A, and V3 represents a voltage at an output end of the operational amplifier U1A.

[0031] In a specific embodiment, in the signal conditioning module 4, the resistance r2 of the second resistor R2 and the resistance r5 of the fifth resistor R5 satisfy: r2 = r5 = 5.99KΩ, the resistance r3 of the third resistor R3 and the resistance r6 of the sixth resistor R6 satisfy: r3 = r6 = 10KΩ, the resistance r1 of the first resistor R1 and the resistance r4 of the fourth resistor R4 satisfy: r1 = r4 = 10KΩ, and the DC bias voltage signal has a value VR = 1.65V. At this time, the normal judgment voltage value V 正常 = VR = 1.65V, and the broken line judgment voltage value V 断 = 2.09V.

[0032] Taking the sine differential signal output by the resolver as an example, when normally input to the signal conditioning module 4, the virtual short and virtual open concept of the operational amplifier is used, Vp = Vn, that is: Therefore, we have: It can be seen that the output voltage V3 is related to the difference between the input voltages V2 and V1 and the ratio of the third resistor R3 to the second resistor R2. The result determination module 52 samples the peak voltage value V and the trough voltage value V of the digital signal, obtains the average value of the sum of the peak voltage value and the trough voltage value of the digital signal as the final detection result, and the average value V3 均 = VR = 1.65V.

[0033] When the positive differential signal SIN+ in the filtered differential signal or the negative differential signal SIN- in the filtered differential signal is broken, the virtual short and virtual open concept of the operational amplifier is also used, Vp = Vn, that is: Using the node current method, the current flowing through the first resistor R1 is equal to the sum of the currents flowing through the second resistor R2 and the fourth resistor R4, that is: When the resistances have values r2 = r5, r3 = r6, and r1 = r4, we have: It can be seen that at this time, the value of V3 is only related to the resistance values in the circuit and the value VR of the DC bias voltage signal, and is independent of the input signals V1 and V2. The output is a fixed voltage. When the resistances have the values in the above embodiment, V3 = 2.09V, the average value of the sum of the peak voltage value and the trough voltage value of the digital signal is obtained as the final detection result, and the average value V3 均 = 2.09V.

[0034] According to the final detection result, the result determination module 52 determines whether the line is broken. If the final detection result is 1.65V, it is determined to be normal, and if the final detection result is 2.09V, it is determined to be broken. Therefore, it can be determined in real time whether the output signal of the resolver 1 has a broken line fault.

[0035] Example 2: Figure 3 As shown, the angle compensation method using the above-mentioned open circuit detection system for rotary transformers includes the following steps:

[0036] P1. Set up a decoding control module 61, an angle compensation module 62, and an error reporting module 63. The decoding control module 61 has a built-in disconnection event recording module 64 for generating disconnection event record values. The angle compensation module 62 receives the disconnection result judgment signal or normal result judgment signal generated by the result judgment module 52. When the angle compensation module 62 receives the normal result judgment signal and the disconnection event record value of the disconnection event recording module 64 is zero, the decoding control module 61 controls the decoding module 71 in the external motor control system to perform normal decoding of the detection signal output by the signal conditioning module 4. When the angle compensation module 62 receives the normal result judgment signal and the disconnection event record value of the disconnection event recording module 64 is zero, the decoding control module 61 controls the decoding module 71 in the external motor control system to perform normal decoding of the detection signal output by the signal conditioning module 4. When block 62 receives the disconnection result judgment signal, it controls the decoding module 71 to pause the decoding process through the decoding control module 61. The angle compensation module 62 records the first angle θ1 decoded by the decoding module 71 at the time of disconnection. The angle compensation module 62 sends the disconnection status signal to the speed control module 72 in the external motor control system. After receiving the disconnection status signal, the speed control module 72 controls the motor to continue running at the current average speed v1 in open-loop mode. At the same time, the disconnection event recording module 64 sets the disconnection event recording value to 1 and starts counting at a fixed counting period, and executes step P2.

[0037] P2. The disconnection event recording module 64 sets a maximum disconnection count threshold. When the count value of the disconnection event recording module 64 exceeds the set maximum disconnection count threshold, the disconnection event recording module 64 generates an error signal and sends it to the error reporting module 63 to generate corresponding error information. If the angle compensation module 62 has received a normal result judgment signal before the count value of the disconnection event recording module 64 reaches the maximum disconnection count threshold, the disconnection event recording module 64 clears the count value to zero and sets the disconnection event recording value to zero. The angle compensation module 62 obtains the total rotation angle θ2 of the rotary transformer 1 during the time period t1 from the time T1 when the disconnection result judgment signal is received to the time T2 when the normal result judgment signal is received. θ2 = v1 × t1. Then, step P3 is executed.

[0038] P3. At time T2, the decoding module 71 is controlled by the decoding control module 61 to restart the decoding process and decode to obtain the second angle θ3 at time T2.

[0039] P4, Angle Compensation Module 62 obtains the compensation angle θ4, θ4 = mod(θ3 - θ1 - θ2, 360°), where mod is the modulo function;

[0040] P5, the speed control module 72 takes the sum of θ4 and the preset angle increment θ5 of the next control period at T2 as a new angle increment, and continues to control the motor to rotate, and the new angle increment θ6 satisfies: θ6 = θ4 + θ5.

[0041] In general, the actual mechanical angle of the resolver 1 can be calculated by decoding through the decoding module 71, and during the wire breakage, the actual mechanical angle cannot be obtained, and only an estimated angle can be obtained through the previous average speed, and there is an error between the actual mechanical angle and the estimated angle; after compensation, the error between the actual mechanical angle and the mechanical angle in the software level can be eliminated, and the normal operation of the motor is ensured.

[0042] Based on the above specific implementation scheme, the wire breakage of the driver carrying a heavy object in the actual working condition is simulated, and a test platform for simulating wire breakage is built by using two servo drivers, one of which is used as a test driver, and the other is used as a load driver and is only enabled without setting other parameters, and is used to provide load for the test driver. The specific test process is as follows:

[0043] S1, a relay is connected to one of the encoder output signal lines of the resolver 1, and the closing and opening of the relay are used to simulate a signal wire breakage;

[0044] S2, the waveform of one channel of the signal generator is set as a pulse signal, and the pulse width of the set pulse signal is used to control the time of the relay disconnection, and here the setting is to trigger a 40ms wire breakage every 5 seconds;

[0045] S3, the other channel of the signal generator is connected to the throttle simulation signal, and the waveform of the throttle simulation signal is set as a triangular wave to simulate the acceleration and deceleration of the throttle;

[0046] S4, after half an hour of testing, the driver has been disconnected for 360 times, and the zero position of the test driver is found, and the zero position is not lost, which indicates that the above angle compensation method will not cause the cumulative error of the encoder, and finally lead to the situation that the encoder cannot find the zero position.

[0047] As Figure 4 shown, the horizontal axis represents the time axis, the unit is millisecond, the A1 waveform is the Track A signal of the encoder, the A2 waveform is the actual mechanical angle, the A3 waveform is the actual speed of the motor, and the A4 waveform represents the actual torque current Iq of the encoder.

[0048] It can be seen that when the Track A signal is disconnected, the algorithm successfully detects the disconnection and keeps the motor speed unchanged during the signal loss period; after the signal is restored, there is a slight jump between 60ms and 65ms on the A2 waveform, which is the compensation of the angle error. Since the angle error is compensated, the current on the A4 waveform has a small fluctuation. As can be seen from the current change before and after the disconnection of the A4 waveform, the compensation error indeed causes the actual torque current Iq to increase, and the actual torque current Iq fluctuation can be controlled within an acceptable range through the angle compensation method.

[0049] Through the above test, it is shown that the disconnection detection system and the angle compensation method proposed in the embodiment can realize disconnection detection during encoder disconnection and compensation of error angle after signal recovery. In the process, no error is accumulated, and the current is not too large.

Claims

1. A broken wire detection system for a rotary transformer, characterized by The application discloses a signal detection device for detecting wire breakage, which comprises an amplification module, a filtering module, a signal conditioning module and a detection module. The signal conditioning module comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor and an operational amplifier.

2. The open-winding detection system of claim 1, wherein The detection module comprises an AD conversion module and a result judging module. The result judging module judges whether the final detection result is equal to the wire breakage judging voltage value or the normal judging voltage value. The result judging module generates a wire breakage result judging signal when the final detection result is equal to the wire breakage judging voltage value.

3. A broken wire detection system for a rotary transformer as claimed in claim 2, wherein The signal conditioning module, the resistance r2 of the second resistor and the resistance r5 of the fifth resistor satisfy: r2=r5, the resistance r3 of the third resistor and the resistance r6 of the sixth resistor satisfy: r3=r6, the resistance r1 of the first resistor and the resistance r4 of the fourth resistor satisfy: r1=r4, the direct current bias voltage signal V R =1.65V, at this time the normal judgment voltage value V 正常 =V R =1.65V.

4. A broken wire detection system for a rotary transformer as claimed in claim 3, characterized in that The signal conditioning module, the resistance r2 of the second resistor and the resistance r5 of the fifth resistor satisfy: r2=r5=5.99KΩ, the resistance r3 of the third resistor and the resistance r6 of the sixth resistor satisfy: r3=r6=10KΩ, the resistance r1 of the first resistor and the resistance r4 of the fourth resistor satisfy: r1=r4=10KΩ, the direct current bias voltage signal V R =1.65V, at this time the normal judgment voltage value V 正常 =V R =1.65V, the broken line judgment voltage value V 断 =2.09V.

5. An angle compensation method of a broken wire detection system using the resolver as claimed in claim 2, characterized in that The result judging module generates a normal result judging signal when the final detection result is equal to the normal judging voltage value. The application further discloses a signal detection method for detecting wire breakage. P1, a decoding control module, an angle compensation module and an error reporting module are provided. The decoding control module is internally provided with a wire breakage event record module for generating a wire breakage event record value. The angle compensation module receives the wire breakage result judging signal or the normal result judging signal generated by the result judging module. When the angle compensation module receives the normal result judging signal and the wire breakage event record value of the wire breakage event record module is zero, the decoding control module is used to control a decoding module in an external motor control system to normally decode the detection signal output by the signal conditioning module. When the angle compensation module receives the broken line result determination signal, the decoding process is paused by the decoding control module, the first angle θ1 decoded by the decoding module at the time of broken line is recorded by the angle compensation module, and the broken line state signal is sent to the speed control module in the external motor control system. After receiving the broken line state signal, the speed control module controls the motor to continue running at the average speed v1 at the current time in open loop mode. Meanwhile, the broken line event recording module sets the broken line event recording value to 1 and starts counting at a fixed counting period, and step P2 is performed. P2, the broken line event recording module sets the maximum broken line counting threshold. When the counting value of the broken line event recording module exceeds the set maximum broken line counting threshold, the broken line event recording module generates an error signal and sends it to the error module to generate corresponding error information. If the angle compensation module has received a normal result determination signal before the counting value of the broken line event recording module reaches the maximum broken line counting threshold, the broken line event recording module clears the counting value and sets the broken line event recording value to zero. The angle compensation module obtains the total rotation angle θ2 of the resolver in the time period from the time T1 when the broken line result determination signal is received to the time T2 when the normal result determination signal is received, θ2=v1×t1, and then step P3 is performed. P3, at time T2, the decoding process is restarted by the decoding control module and the second angle θ3 at time T2 is obtained by decoding; P4, the angle compensation module obtains the compensation angle θ4, θ4=mod(θ3-θ1-θ2, 360°), where mod is the modulus function; P5, the speed control module takes the sum of θ4 and the preset original angle increment θ5 of the next control period at time T2 as the new angle increment, and continues to control the motor to rotate. The new angle increment θ6 satisfies: θ6=θ4+θ5.

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