Signal detection circuit, signal detection method and servo driver

Abstract

The invention discloses a signal detection circuit, a signal detection method and a servo driver, and the signal detection circuit comprises a first signal adjustment module, a detection module and a control module. The first signal adjusting module is used for receiving a first differential signal sent by a motor encoder and adjusting the first differential signal to obtain a second differential signal; the detection module is connected with the first signal adjustment module and is used for detecting the second differential signal to obtain a single-end detection signal for judging whether the first differential signal is disconnected or synchronized; the control module is used for acquiring the single-end detection signal and controlling the motor to stop running under the condition of determining that the first differential signal is disconnected or synchronized according to the single-end detection signal; according to the technical scheme, disconnection or synchronization detection can be effectively performed on the differential signal, so that the working state of the motor can be controlled and processed according to the detection result of the differential signal.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of circuit, in particular to a signal detection circuit, a signal detection method and a servo driver. BACKGROUND

[0002] At present, in order to enable the motor to operate normally, the running process of the motor often needs to be monitored by using the motor encoder, and the position parameter of the motor is fed back through the motor encoder; the motor encoder often feeds back the single-ended detection signal in the form of differential signal to the control end, however, the differential signal may appear broken line or synchronization, but the current motor system cannot effectively detect whether the differential signal appears broken line or synchronization, thereby easily affecting the normal work of the motor. SUMMARY

[0003] The embodiments of the present application provide a signal detection circuit, a signal detection method and a servo driver, which can effectively detect the broken line or synchronization of the differential signal, so as to control and process the working state of the motor according to the detection result of the differential signal.

[0004] The embodiments of the first aspect of the present application provide a signal detection circuit, comprising:

[0005] A first signal adjusting module is configured to receive a first differential signal sent by a motor encoder and adjust the first differential signal to obtain a second differential signal;

[0006] A detection module is connected with the first signal adjusting module and configured to detect the second differential signal to obtain a single-ended detection signal for judging whether the first differential signal appears broken line or synchronization;

[0007] A control module is configured to acquire the single-ended detection signal and control the motor to stop running when it is determined that the first differential signal appears broken line or synchronization according to the single-ended detection signal.

[0008] The signal detection circuit according to the first aspect of the present application has at least the following beneficial effects: the first signal adjusting module is configured to receive a first differential signal sent by a motor encoder and adjust the received first differential signal to obtain a second differential signal; the detection module is configured to detect the second differential signal to obtain a single-ended detection signal for judging whether the first differential signal appears broken line or synchronization; and the control module is configured to control the motor to stop running when it is determined that the first differential signal appears broken line or synchronization according to the single-ended detection signal. Through the above technical solution, the broken line or synchronization of the differential signal can be effectively detected, so as to control and process the working state of the motor according to the detection result of the differential signal.

[0009] In some embodiments, the signal detection circuit further comprises a signal conversion module, which is arranged between the first signal adjustment module and the control module, and is configured to convert the second differential signal into a single-ended control signal, and send the single-ended control signal to the control module.

[0010] The control module is further configured to acquire the single-ended control signal, and control the working state of the motor according to the single-ended control signal when it is determined that the first differential signal has no disconnection or synchronization according to the single-ended detection signal.

[0011] In some embodiments, the signal detection circuit further comprises a second signal adjustment module, which is arranged between the signal conversion module and the control module, and is configured to perform signal shaping on the single-ended control signal to obtain a motor control signal, and send the motor control signal to the control module, so that the control module controls the working state of the motor according to the motor control signal.

[0012] In some embodiments, the first signal adjustment module comprises at least one of the following:

[0013] A first resistor and a first capacitor, which are connected in parallel between a first signal line and a first reference power supply, and a first signal input end of the signal conversion module and a first signal input end of the detection module are both connected to the first signal line.

[0014] A second resistor and a second capacitor, which are connected in parallel between the first signal line and a second signal line, and a first signal input end of the signal conversion module and a first signal input end of the detection module are both connected to the first signal line, and a second signal input end of the signal conversion module and a second signal input end of the detection module are both connected to the second signal line.

[0015] A third resistor and a third capacitor, which are connected in parallel between the second signal line and a reference ground, and a second signal input end of the signal conversion module and a second signal input end of the detection module are both connected to the second signal line.

[0016] In some embodiments, the detection module comprises a fourth capacitor, a fourth resistor, a fifth resistor and a comparator, one end of the fourth capacitor is connected between the first comparison input and the second comparison input of the comparator, the other end of the fourth capacitor is connected to the first reference power source through the fourth resistor, the other end of the fourth capacitor is connected to the reference ground through the fifth resistor, the first comparison input and the second comparison input of the comparator are used to receive the second differential signal, and the output end of the comparator is used to output the single-end detection signal.

[0017] In some embodiments, the detection module further comprises a rectifier bridge, a sixth resistor and a seventh resistor, the rectifier bridge comprises a first input end, a second input end, a first output end and a second output end, the first input end of the rectifier bridge is connected to the first signal output end of the first signal adjustment module through the sixth resistor, the second input end of the rectifier bridge is connected to the second signal output end of the first signal adjustment module through the seventh resistor, the first output end of the rectifier bridge is connected between the fourth resistor and the fourth capacitor, and the second output end of the rectifier bridge is connected between the fifth resistor and the fourth capacitor.

[0018] In some embodiments, the second signal adjustment module comprises a Schmitt trigger, the signal input end of the Schmitt trigger is connected to the output end of the signal conversion module, the signal output end of the Schmitt trigger is connected to the control module, the bias end of the Schmitt trigger is connected to the second reference power source, and the ground end of the Schmitt trigger is connected to the reference ground.

[0019] The second aspect embodiment of the present application provides a signal detection method, applied to a signal detection circuit, the signal detection circuit comprising a first signal adjustment module and a detection module, the first signal adjustment module being connected to the detection module;

[0020] The method comprises:

[0021] obtaining a single-end detection signal sent by the detection module, wherein the single-end detection signal is obtained by detecting a second differential signal sent by the first signal adjustment module, and the second differential signal is obtained by adjusting and processing a first differential signal sent by a motor encoder by the first signal adjustment module;

[0022] determining whether the first differential signal appears a wire breakage or synchronization according to the single-end detection signal, and controlling the motor to stop running when it is determined that the first differential signal appears a wire breakage or synchronization according to the single-end detection signal.

[0023] In some embodiments, the determining whether the first differential signal has a disconnection or synchronization condition according to the single-end detection signal comprises:

[0024] When the voltage amplitude of the single-end detection signal is equal to a first preset amplitude, it is determined that the first differential signal has a disconnection or synchronization condition;

[0025] When the voltage amplitude of the single-end detection signal is equal to a second preset amplitude, it is determined that the first differential signal does not have a disconnection or synchronization condition;

[0026] The second preset amplitude is greater than the first preset amplitude.

[0027] In some embodiments, the signal detection circuit further comprises a signal conversion module, which is arranged between the first signal adjustment module and the control module.

[0028] The method further comprises:

[0029] obtaining the single-end control signal sent by the signal conversion module, wherein the single-end control signal is obtained by signal conversion of the second differential signal sent by the first signal adjustment module by the signal conversion module;

[0030] When it is determined according to the single-end detection signal that the first differential signal does not have a disconnection or synchronization condition, the working state of the motor is controlled according to the single-end control signal.

[0031] The third aspect embodiment of the present application provides a servo driver, which comprises the signal detection circuit of the first aspect embodiment.

[0032] Other features and advantages of the present application will be illustrated in the following description, and some will become apparent from the description, or will be understood by those skilled in the art. The purpose and other advantages of the present application can be achieved and obtained by the structure specifically pointed out in the specification, claims and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is a circuit principle schematic diagram of the signal detection circuit provided by the embodiment of the present application;

[0034] Figure 2 is a circuit principle schematic diagram of the signal detection circuit provided by another embodiment of the present application;

[0035] Figure 3 is a specific circuit principle diagram of the signal detection circuit provided by the embodiment of the present application;

[0036] Figure 4is a flow chart of a signal detection method provided by an embodiment of the present application;

[0037] Figure 5 is a flow chart of detecting a single-ended detection signal provided by an embodiment of the present application;

[0038] Figure 6 is a flow chart of a signal detection method provided by another embodiment of the present application.

[0039] Reference signs:

[0040] The motor encoder 100, the first signal adjustment module 200, the detection module 300, the signal conversion module 500, the control module 400, the second signal adjustment module 600, and the common-mode signal filtering module 700. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application. In addition, the features, operations or characteristics described in the specification can be combined in any appropriate manner to form various embodiments. At the same time, the steps or actions in the method description can also be sequentially changed or adjusted in a manner obvious to those skilled in the art. Therefore, the order in the specification and the drawings is only for clear description of an embodiment and does not mean a necessary order, unless otherwise stated that a certain order must be followed.

[0042] In the description of the present application, one or more is meant to be one or more, more than two is meant to be more than two, greater than, less than, more than, etc. are understood to not include the number, above, below, etc. are understood to include the number. If it is described as first, second, it is only used to distinguish technical features for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or implicitly indicating the sequence of indicated technical features.

[0043] In this paper, the serial number of the component itself, such as "first", "second", etc., is only used to distinguish the described object, and does not have any order or technical meaning. Unless otherwise specified, the "connection" and "coupling" in the present application include direct and indirect connection (coupling).

[0044] At present, in order to enable the motor to operate normally, the motor encoder is often used to monitor the operation process of the motor, and the position parameter of the motor is fed back through the motor encoder; the motor encoder often uses the form of differential signal to feed back the single-end detection signal to the control end, however, the differential signal may appear broken line or signal synchronization, but the current motor system cannot effectively detect whether the differential signal appears broken line or signal synchronization, thereby easily affecting the normal work of the motor.

[0045] Based on this, the embodiment of the application provides a signal detection circuit, a signal detection method and a servo driver, which can effectively detect the broken line or synchronization of the differential signal, so as to adjust and control the working state of the motor according to the detection result of the differential signal.

[0046] The following will be described with reference to the drawings:

[0047] With reference to Figure 1 The signal detection circuit provided by the embodiment of the application comprises a first signal adjustment module 200, a detection module 300 and a control module 400; the first signal adjustment module 200 can receive and process the first differential signal sent by the motor encoder 100, and then the first signal adjustment module 200 can perform signal shaping processing on the first differential signal to obtain a second differential signal; the detection module 300 can detect and process the second differential signal to obtain a single-end detection signal; the control module 400 can receive and process the single-end detection signal, analyze and process the received single-end detection signal to obtain a detection result, and then when the detection result represents that the first differential signal appears broken line or signal synchronization, the control module 400 will immediately stop the motor from operating; through the above technical solution, the broken line or synchronization of the differential signal can be effectively detected, so that the working state of the motor can be adjusted and controlled according to the detection result of the differential signal, and the control process of the motor can be more stable and reliable.

[0048] Specifically, in the process of motor operation, the motor encoder 100 is used to measure and monitor the speed and position of the rotating shaft of the motor, and then converts the detected detection condition into a first differential signal, which is used to represent the current operation condition of the motor; in order to further improve the anti-interference characteristic of the first differential signal, the first signal adjustment module 200 can be used to filter and shape the first differential signal to obtain a second differential signal; wherein the first differential signal and the second differential signal are both differential signals, and they belong to the same type of signal, and the use of "first" and "second" is only for better description and illustration of the technical solution of the application, and does not mean that they belong to different types of signals.

[0049] It can be understood that, in order to improve the anti-interference characteristics of the first differential signal, the first signal adjusting module 200 can filter and shape the first differential signal sent by the motor encoder 100, so that the first differential signal can be adjusted to the second differential signal, and the subsequent signal detection is prepared.

[0050] Specifically, based on the detection of the second differential signal by the detection module 300, a single-ended detection signal can be obtained; wherein, the second differential signal is mainly detected to detect whether the first differential signal has a broken line or signal synchronization condition. When the single-ended detection signal detected by the detection module 300 represents that the received first differential signal has a broken line or signal synchronization condition, the control module 400 will control the motor to stop working, so as to prevent the abnormal working condition of the motor from occurring.

[0051] It can be understood that, when the control module 400 receives the single-ended detection signal, the control module 400 can analyze the single-ended detection signal; when the single-ended detection signal represents that the received first differential signal has a broken line or signal synchronization condition, the control module 400 will control the operation of the motor according to the received single-ended detection signal; through the above technical solution, the broken line or signal synchronization condition of the first differential signal can be effectively detected, so that the control process of the motor can be more reliable and reasonable.

[0052] It is worth noting that the control module 400 can be an arithmetic device, in the embodiment of the present application, the control module 400 can be a single-chip microcomputer control chip, a digital conversion chip and other electronic devices with arithmetic function, which is not limited here.

[0053] It is worth noting that the motor encoder 100 is a kind of sensor for measuring mechanical rotation or displacement; it can measure the displacement position or speed of mechanical components during rotation or linear motion and convert it into a series of electrical signals. According to the monitoring principle, the motor encoder 100 can be classified into photoelectric encoder and Hall encoder. The photoelectric encoder is a sensor that converts the mechanical geometric displacement on the output shaft into pulse or digital quantity through photoelectric conversion. It is the most widely used sensor at present, and the photoelectric encoder is composed of a light source, a light code disc and a photosensitive element. The Hall encoder is a sensor that converts the mechanical geometric displacement on the output shaft into pulse or digital quantity through magnetic-electric conversion. The Hall encoder is composed of a Hall code disc (magnetic ring) and a Hall element. According to the output signal, the motor encoder 100 can be divided into incremental encoder and absolute encoder. The incremental encoder converts the displacement information of the device during movement into continuous pulse signals, and the number of pulses represents the size of the displacement. The absolute encoder is similar in overall structure to the incremental encoder, and is composed of a code disc, a detection device and an amplification shaping circuit. However, the specific code disc structure and output signal meaning are different. It converts the displacement information of the device during movement into digital quantity directly output through binary encoding (special code disc). For the incremental encoder, the signals of each channel are independently output, and the output circuit forms are usually collector open circuit output, push-pull output, differential output, etc. For the absolute encoder, since it directly outputs dozens of binary numbers, in order to ensure the transmission rate and signal quality, it generally adopts serial output or bus type output, and a part of it is parallel output. The output circuit form is the same as that of the incremental encoder. The motor encoder 100 in the embodiment of the application can be selected according to actual needs.

[0054] With reference to Figure 2 The signal detection circuit can further include a signal conversion module 500, which can perform signal conversion processing on the second differential signal sent by the first signal adjustment module 200 to obtain a single-ended control signal. The signal conversion module 500 sends the single-ended control signal obtained by signal conversion to the control module 400. In the case that the first differential signal is not disconnected or the signals are synchronized, the control module 400 will adjust and control the working state of the motor according to the received single-ended control signal, so that the control process of the motor can be more stable and reliable.

[0055] Specifically, the signal conversion module 500 and the first signal adjustment module 200 are electrically connected, and then the signal conversion module 500 can receive the second differential signal sent by the first signal adjustment module 200, and can also convert the received second differential signal into a single-ended control signal to adjust and control the working state of the motor by using the single-ended control signal. Wherein, the single-ended control signal only uses one line to transmit the signal, plus a reference line, which can be a ground wire; the cost of single-ended control signal is low, and the signal transmitted on the single-ended control signal line is the potential difference between the signal line and the ground line. It is worth noting that single-ended signal is used in low-frequency circuit, which is suitable for high-amplitude signal, but not for low-amplitude signal. Differential signal is often used in high-speed circuit, differential signal is two signal lines, differential is also called differential function or differential operation, the result of differential reflects the change between discrete quantities; the two transmission lines of the differential signal change with the ground at the same time, so the difference is fixed, so the anti-interference ability of the differential signal is relatively strong, and the noise is also loaded on the two transmission lines at the same time, the difference is zero; in addition, the two lines of the differential signal are close and the signal amplitude is equal, which makes the coupling electromagnetic field between the two lines and the ground line equal, and the signal polarity is opposite, the electromagnetic field cancels out each other, and the electromagnetic interference to the outside is relatively small.

[0056] It can be understood that when the control module 400 receives the single-ended detection signal and the single-ended control signal, the control module 400 can comprehensively analyze the single-ended detection signal and the single-ended control signal; in the case that the single-ended detection signal represents that the received first differential signal has a broken line or signal synchronization, the control module 400 will control the operation of the motor according to the received single-ended detection signal, and will not control the operation state of the motor by using the received single-ended control signal; when the single-ended detection signal represents that the received first differential signal does not have a broken line or signal synchronization, the control module 400 will control the operation of the motor according to the received single-ended detection signal; through the above technical solution, the control process of the motor can be more reliable and reasonable.

[0057] Referring to Figure 2 , the signal detection circuit further comprises a second signal adjustment module 600, the signal input end of the second signal adjustment module 600 is connected with the signal output end of the signal conversion module 500, and the signal output end of the second signal adjustment module 600 is connected with the signal input end of the control module 400, so that the second signal adjustment module 600 can perform shaping processing on the single-ended control signal output by the signal conversion module 500, to further improve the anti-interference characteristic of the signal, so that the control process of the motor can be more stable and reliable.

[0058] Specifically, in order to further improve the anti-interference ability of the signal, the single-ended control signal output by the signal conversion module 500 can be further subjected to signal shaping processing to filter out the distortion in the signal, so as to obtain a motor control signal; finally, the obtained motor control signal is sent to the control module 400, so that the control module 400 can use the motor control signal to adjust and control the working state of the motor when there is no disconnection or signal synchronization in the first differential signal, thereby further improving the stability and reliability of the motor control.

[0059] Specifically, the second signal adjustment module 600 can effectively identify the signal distortion of the single-ended control signal output by the signal conversion module 500, improve the signal transmission quality, and can well ensure the correctness of the single-ended control signal. The first signal adjustment module 200 and the second signal adjustment module 600 can improve the anti-interference capability, thereby improving the reliability of the signal detection circuit. It is worth noting that in some embodiments of the present application, the second signal adjustment module 600 is used to shape the single-ended control signal, so that the deformed signal in the single-ended control signal output by the signal conversion module 500 can be adjusted and processed well, so as to well eliminate the deformed signal in the single-ended control signal, so that the subsequent motor control process can be more stable.

[0060] In some embodiments of the present application, the signal detection circuit may further include a common-mode signal filtering module 700, which is electrically connected to the first signal adjustment module 200. When the common-mode noise in the first differential signal output by the motor encoder 100 passes through the common-mode signal filtering module 700, the common-mode signal filtering module 700 will filter the common-mode noise in the first differential signal, so that the first differential signal input into the first signal adjustment module 200 will not be interfered by the common-mode noise, and the subsequent signal shaping process can be more stable and accurate.

[0061] Specifically, in some embodiments of the present application, the common-mode signal filtering module 700 can be a common-mode inductor, which is also called a common-mode choke. The common-mode inductor can filter common-mode electromagnetic interference signals; the common-mode inductor can also play a filtering role, used to suppress the electromagnetic waves generated on the high-speed signal line from radiating outward. It is worth noting that the first differential signal includes a first differential sub-signal and a second differential sub-signal. The first differential sub-signal and the second differential sub-signal pass through the common-mode inductor, and the common-mode noise in the first differential sub-signal and the second differential sub-signal can be filtered out, so that the common-mode noise in the first differential sub-signal and the second differential sub-signal is filtered out, further improving the anti-interference ability of the signal. The first differential sub-signal and the second differential sub-signal have equal amplitudes, a phase difference of 180 degrees, and opposite polarities.

[0062] ReferenceFigure 3 In some embodiments of the present application, the first signal adjustment module 200 can include a first resistor R1 and a first capacitor C1, one end of the first capacitor C1 is connected with one end of the first resistor R1, and the other end of the first capacitor C1 is connected with the other end of the first resistor R1; one end of the first capacitor C1 and one end of the first resistor R1 are both connected with the first reference power supply, and the other end of the first capacitor C1 and the other end of the first resistor R1 are also both connected with the first signal input end of the signal conversion module 500, and the other end of the first capacitor C1 and the other end of the first resistor R1 are also both connected with the first signal input end of the detection module 300; through the above technical solution, the first differential signal input by the motor encoder 100 can be subjected to signal shaping and filtering processing through the first resistor R1 and the first capacitor C1, so as to improve the anti-interference ability of the signal. It is worth noting that the first resistor R1 and the first capacitor C1 are connected in parallel between the first signal line and the first reference power supply, the first signal line is the signal line to which the other end of the first capacitor C1 and the other end of the first resistor R1 are connected, and the first signal line is used for transmitting the differential signal.

[0063] In some embodiments of the present application, the first signal adjustment module 200 can further include a second resistor R2 and a second capacitor C2, one end of the second resistor R2 and one end of the second capacitor C2 are connected, and the other end of the second resistor R2 and the other end of the second capacitor C2 are connected; one end of the second resistor R2 and one end of the second capacitor C2 are also connected with the first signal input end of the signal conversion module 500, and one end of the second resistor R2 and one end of the second capacitor C2 are also connected with the first signal input end of the detection module 300; the other end of the second resistor R2 and the other end of the second capacitor C2 are also connected with the second signal input end of the signal conversion module 500, and the other end of the second resistor R2 and the other end of the second capacitor C2 are also connected with the second signal input end of the detection module 300. Through the above technical solution, the first differential signal input by the motor encoder 100 is subjected to signal shaping and filtering processing by the second resistor R2 and the second capacitor C2. It is worth noting that the first resistor R1 is also connected with the second resistor R2, and the first capacitor C1 is also connected with the second capacitor C2, further improving the signal shaping and filtering capability of the first signal adjustment module 200. It is worth noting that the second resistor R2 and the second capacitor C2 are connected in parallel between the first signal line and the second signal line, the second signal line is the signal line to which the other end of the second resistor R2 and the other end of the second capacitor C2 are connected, and the second signal line is also used for transmitting the differential signal.

[0064] In some embodiments of the present application, the first signal adjustment module 200 can further include a third capacitor C3 and a third resistor R3, one end of the third capacitor C3 and one end of the third resistor R3 are connected with the reference ground, the other end of the third resistor R3 and the other end of the third capacitor C3 are connected, the other end of the third resistor R3 and the other end of the third capacitor C3 are also connected with the second signal input end of the signal conversion module 500, and the other end of the third resistor R3 and the other end of the third capacitor C3 are also connected with the second signal input end of the detection module 300; through the above technical solution, the first differential signal input by the motor encoder 100 can also be subjected to signal shaping and filtering processing through the third resistor R3 and the third capacitor C3, so as to well improve the anti-interference ability of the signal. It is worth noting that the other end of the third resistor R3 is also connected with the second resistor R2, and the other end of the third capacitor C3 is also connected with the second capacitor C2; through the above technical solution, the signal shaping and filtering performance of the first signal adjustment module 200 is further improved. It is worth noting that the third resistor R3 and the third capacitor C3 are connected in parallel between the second signal line and the reference ground.

[0065] With reference to Figure 3 In some embodiments of the present application, the detection module 300 includes a fourth capacitor C4, a fourth resistor R4, a fifth resistor R5 and a comparator U3A, one end of the fourth capacitor C4 is connected to the first comparison input end of the comparator U3A, and the other end of the fourth capacitor C4 is connected to the second comparison input end of the comparator U3A; one end of the fourth capacitor C4 is also connected with one end of the fourth resistor R4, the other end of the fourth resistor R4 is also connected with the first reference power supply, the other end of the fourth capacitor C4 is also connected with one end of the fifth resistor R5, and the other end of the fifth resistor R5 is also connected with the reference ground; wherein the fourth resistor R4 and the fifth resistor R5 provide a bias voltage for the two ends of the fourth capacitor C4, and the comparator U3A can control the output of the single-ended detection signal according to the voltage at the two ends of the fourth capacitor C4, so that the detection of the first differential signal can be more accurate and reliable.

[0066] With reference to Figure 3In some embodiments of the present application, the detection module 300 further comprises a rectifier bridge D1, a sixth resistor R6 and a seventh resistor R7. The rectifier bridge D1 comprises a first input end, a second input end, a first output end and a second output end. The first input end of the rectifier bridge D1 is connected to one end of the sixth resistor R6, and the other end of the sixth resistor R6 is further connected to the first signal output end of the first signal adjustment module 200. The second input end of the rectifier bridge D1 is connected to one end of the seventh resistor R7, and the other end of the seventh resistor R7 is further connected to the second signal output end of the first signal adjustment module 200. The first output end of the rectifier bridge D1 is connected between the fourth resistor R4 and the fourth capacitor C4, and the second output end of the rectifier bridge D1 is connected between the fifth resistor R5 and the fourth capacitor C4. The second differential signal comprises a third differential sub-signal and a fourth differential sub-signal. The first signal output end of the first signal adjustment module 200 can output the third differential sub-signal, and correspondingly the second signal output end of the first signal adjustment module 200 can output the fourth differential sub-signal. Alternatively, the first signal output end of the first signal adjustment module 200 can output the fourth differential sub-signal, and correspondingly the second signal output end of the first signal adjustment module 200 can output the third differential sub-signal. Through the above technical solution, the third differential sub-signal and the fourth differential sub-signal first need to be rectified and deformed by the rectifier bridge D1, and then input to both ends of the fourth capacitor C4. The voltage across the fourth capacitor C4 will change according to the third differential sub-signal and the fourth differential sub-signal. The comparator U3A can control the output end according to the voltage change across the fourth capacitor C4. The subsequent control module 400 can determine whether the first differential signal output by the motor encoder 100 has a wire breakage or signal synchronization condition according to the voltage output by the comparator U3A, so that the control module 400 can control the working state of the motor. When it is judged that the first differential signal has a wire breakage or signal synchronization condition, the control module 400 will immediately control the motor to stop working. When it is judged that the first differential signal does not have a wire breakage or signal synchronization condition, the control module 400 will control the working state of the motor according to the single-ended control signal converted by the signal conversion module 500, so that the control of the motor can be more stable and reliable.

[0067] Specifically, the rectifier bridge D1 can perform signal rectification processing on the second differential signal. The fourth capacitor C4 acts as a filter capacitor. When the first differential signal output by the motor encoder 100 has a wire breakage or signal synchronization condition, the voltage across the fourth capacitor C4 will decrease. When the voltage across the fourth capacitor C4 decreases to the point that the differential input end voltage difference of the comparator U3A is reversed, the output level of the comparator U3A will change, so that the single-ended detection signal output by the detection module 300 will also change, and the control module 400 can control the working state of the motor according to the received detection result.

[0068] Specifically, the rectifier bridge in the present application can be connected by four independent diodes, or can be made together into a rectifier bridge element using semiconductor materials. The rectifier bridge generally has a large inductive load, so the rectifier bridge does not appear to be current discontinuous. Generally, the rectifier bridge is applied to the load end of the smoothing reactor, so the load can be considered as a constant current source; multiple sets of three-phase rectifier bridges are connected to each other, so that the harmonics generated by the rectifier bridge circuit cancel each other out. The rectification of the rectifier bridge is completed by the unidirectional conduction principle of the diode. In simple terms, the diode is forward biased and reverse biased, that is, the diode only allows the positive electrode to enter the positive electricity and the negative electrode to enter the negative electricity. The diode only allows current to flow in one direction, so when it is connected to an alternating current circuit, it can make the current in the circuit flow in only one direction; the rectifier is usually composed of four diodes for single-phase bridge full-wave rectifiers and six diodes for three-phase bridge full-wave rectifiers; used in single-phase and three-phase rectification; for single-phase bridge full-wave rectifiers, only two diodes work at the same time in each working cycle of the rectifier bridge, and through the unidirectional conduction function of the diode, the alternating current is converted into a unidirectional direct current pulsed voltage.

[0069] Reference Figure 3 In some embodiments of the present application, the second signal adjustment module 600 can be a Schmitt trigger U2A, the output end of the signal conversion module 500 and the signal input end of the Schmitt trigger U2A are connected, the signal output end of the Schmitt trigger U2A is connected to the signal input end of the control module 400, the bias end of the Schmitt trigger U2A is connected with the second reference power supply, and the ground end of the Schmitt trigger U2A is connected with the reference ground, so that the Schmitt trigger U2A can further perform signal shaping processing on the single-ended signal output by the signal conversion module 500, so that the output single-ended signal has stronger anti-interference characteristics, thereby being able to more stably control and process the working state of the motor. The Schmitt trigger U2A is a comparator U3A circuit with hysteresis, which is realized by applying positive feedback to the non-inverting input end of the comparator U3A or the differential amplifier, the Schmitt trigger U2A uses two input different threshold voltage levels to avoid noise in the input signal, and the function of this double threshold is called hysteresis; the Schmitt trigger U2A is a bistable circuit, when the input reaches a certain designed threshold voltage level, the output swings between two stable voltage levels (high and low).

[0070] Reference Figure 4 The signal detection method provided by the embodiment of the present application is applied to a signal detection circuit, and the signal detection circuit comprises a first signal adjustment module and a detection module, and the first signal adjustment module and the detection module are connected. The signal detection method can include but is not limited to steps S100 and S200.

[0071] Step S100, obtaining a single-ended detection signal sent by a detection module, wherein the single-ended detection signal is obtained by the detection module detecting a second differential signal sent by a first signal adjustment module, and the second differential signal is obtained by the first signal adjustment module adjusting and processing a first differential signal sent by a motor encoder;

[0072] Step S200, judging whether the first differential signal appears a wire breakage or synchronization according to the single-ended detection signal, and stopping the motor from running when it is determined that the first differential signal appears a wire breakage or synchronization according to the single-ended detection signal.

[0073] In some embodiments of the present application, the first signal adjustment module in the signal detection circuit receives the first differential signal sent by the motor encoder, and then the first signal adjustment module performs signal shaping processing on the first differential signal to obtain the second differential signal. The detection module can also detect the second differential signal obtained by shaping to obtain a single-ended detection signal to identify whether there is a wire breakage or signal synchronization in the first differential signal, and the motor is stopped from running when the first differential signal appears a wire breakage or synchronization. Specifically, the single-ended detection signal represents that there is a wire breakage or signal synchronization in the first differential signal, and the control module controls the motor to stop working. Specifically, the signal detection method of the embodiments of the present application is executed by the control module in the signal detection circuit.

[0074] Referring to Figure 5 judging whether the first differential signal appears a wire breakage or synchronization according to the single-ended detection signal can include but is not limited to step S210 and step S220.

[0075] Step S210, determining that the first differential signal appears a wire breakage or synchronization when a voltage amplitude of the single-ended detection signal is equal to a first preset amplitude.

[0076] Step S220, determining that the first differential signal does not appear a wire breakage or synchronization when the voltage amplitude of the single-ended detection signal is equal to a second preset amplitude; wherein the second preset amplitude is greater than the first preset amplitude.

[0077] In some embodiments of the present application, the voltage amplitude of the single-ended detection signal is compared with the first preset amplitude and the second preset amplitude respectively, in the case that the voltage amplitude of the single-ended detection signal is equal to the first preset amplitude, it is determined that the first differential signal appears the wire breakage or signal synchronization condition; in the case that the voltage amplitude of the single-ended detection signal is equal to the second preset amplitude, it is determined that the first differential signal does not exist the wire breakage or signal synchronization condition. Exemplarily, the second preset amplitude is 3.3V, the first preset amplitude is 0V, in the case that the voltage amplitude of the single-ended detection signal is equal to 0V, it can be determined that the first differential signal appears the wire breakage or synchronization condition; in the case that the voltage amplitude of the single-ended detection signal is equal to 3.3V, it can be determined that the first differential signal does not appear the wire breakage or synchronization condition.

[0078] Referring to Figure 6 The signal detection circuit further comprises a signal conversion module, which is arranged between the first signal adjustment module and the control module; the signal detection method can further comprise, but is not limited to, steps S300 and S400.

[0079] In step S300, a single-ended control signal sent by the signal conversion module is acquired, wherein the single-ended control signal is obtained by signal conversion of the second differential signal sent by the first signal adjustment module by the signal conversion module;

[0080] In step S400, when it is determined according to the single-ended detection signal that the first differential signal does not exist the wire breakage or signal synchronization condition, the working state of the motor is controlled and processed according to the single-ended control signal.

[0081] In some embodiments of the present application, the first signal adjustment module in the signal detection circuit receives the first differential signal sent by the motor encoder; then the first signal adjustment module performs signal shaping processing on the first differential signal to obtain the second differential signal; the signal conversion module can also perform conversion processing on the second differential signal to obtain the single-ended control signal; the detection module can also perform detection processing on the second differential signal obtained by shaping to obtain the single-ended detection signal, so as to identify whether the first differential signal exists the wire breakage or signal synchronization condition; finally, the control module controls and processes the subsequent working state of the motor based on the single-ended control signal and the single-ended detection signal. Specifically, the single-ended detection signal represents that the first differential signal exists the wire breakage or signal synchronization condition, the control module controls the motor to stop working, and the control module does not control the motor to work according to the single-ended control signal at this time; when the single-ended detection signal represents that the first differential signal does not exist the wire breakage or signal synchronization condition, the control module controls and processes the working state of the motor according to the single-ended control signal, so that the control process of the motor can be more stable and reliable.

[0082] It is worth noting that after the second differential signal is processed by the signal conversion module to obtain a single-ended control signal, the second signal adjustment module can be used to further perform signal shaping processing on the single-ended control signal, so as to better filter out abnormal signals in the signal and enhance the anti-interference characteristics of the single-ended control signal.

[0083] In some embodiments of the present application, when the first differential signal is disconnected or signal synchronization occurs, the control module will control the motor to stop working, and will also send an alarm information to the monitoring end to remind the user that the current motor operation has failed. Through the above technical solution, the user can quickly know the running condition of the motor, which brings great convenience to the user.

[0084] In order to more clearly describe the signal detection method of the present application, a specific embodiment will be described below.

[0085] Referring to Figure 3 , the motor encoder outputs a first differential signal to the first signal adjustment module, the first signal adjustment module filters and shapes the first differential signal to output a second differential signal, and the second differential signal is transmitted to the differential signal converter and the disconnection detection circuit. The differential signal converter converts the second differential signal into a first single-ended signal and outputs it to the second signal adjustment module, and the second signal adjustment module outputs the shaped signal as a second single-ended signal. The operation device receives the second single-ended signal and performs operation processing and controls the motor to run stably. At the same time, the disconnection detection circuit identifies the signal of the second differential signal. If the first differential signal output by the motor encoder has disconnection or signal synchronization, the signal of the second differential signal will also be out of synchronization. At this time, the disconnection detection circuit identifies and outputs a disconnection detection signal to the operation device, the operation device stops the motor from running and sends an alarm information to prompt the user of the error. If the first differential signal has no disconnection or signal synchronization, the disconnection detection signal is invalid, the system will not alarm, and the operation device receives the second single-ended signal and controls the motor to run normally. The operation device in the embodiment of the present application can be used as the control module in the above embodiment. The first single-ended signal is the single-ended control signal, and the disconnection detection circuit is the detection module.

[0086] Specifically, the motor encoder outputs differential signals A and B to the first signal adjustment module, and the first signal adjustment module filters and shapes the differential signals A and B and outputs them to the differential-to-single-ended device U1 and the disconnection detection circuit. The differential signal converter U1 converts the differential signals into a single-ended signal and outputs it to the Schmidt trigger U2A. The U2A outputs the shaped signal AB to the operation device, and the operation device receives the single-ended signal AB and performs operation processing and controls the motor to run stably.

[0087] Meanwhile, the broken line detection circuit rectifies and filters the received differential signal, if the differential signal A, B output by the motor encoder has a broken line or signal synchronization phenomenon, the voltage across the filter capacitor C4 will decrease, when the voltage across C4 decreases to the point that the differential input of U3A flips, the output voltage of U3A changes from 3.3V to 0V. After the broken line detection circuit identifies, it outputs a 0V broken line detection signal to the operation device, the FAIL signal is valid, the operation device will stop the motor running and send an alarm information to prompt the user that there is an error. If the differential signal A, B has no broken line or signal synchronization, the broken line detection signal is high level 3.3V, the FAIL signal is invalid, the system will not alarm and stop, the operation device receives the single-ended signal AB and controls the normal running of the motor.

[0088] In addition, the embodiment of the present application further provides a servo driver, comprising the signal detection circuit.

[0089] The device embodiments described above are merely illustrative, wherein the units described as separate components can or can not be physically separate, i.e., can be located in one place, or can be distributed to multiple network nodes. Part or all of the modules can be selected according to actual needs to achieve the purpose of the embodiment.

[0090] Those skilled in the art can understand that all or some steps in the above disclosed method and system can be implemented as software, firmware, hardware and appropriate combination thereof. Some or all physical components can be implemented as software executed by a processor such as a central processing unit, a digital signal processor or a microprocessor, or as hardware, or as an integrated circuit such as an application specific integrated circuit. Such software can be distributed on a computer readable medium, which can include a computer readable storage medium (or non-transitory medium) and a communication medium (or transitory medium). As known to those skilled in the art, the term computer readable storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. The computer readable storage medium includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disk (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and can be accessed by a computer. In addition, as known to those skilled in the art, communication media generally includes computer readable instructions, data structures, program modules or other data in modulated data signals such as carrier waves or other transmission mechanisms, and can include any information delivery medium.

[0091] The above describes the preferred embodiments of the present application, but the present application is not limited to the above embodiments, and those skilled in the art can make various equivalent modifications or replacements without departing from the spirit of the present application, and these equivalent modifications or replacements are all included in the scope defined by the claims of the present application.

Claims

1. A signal detection circuit, characterized by, The application relates to a signal detection circuit. The signal detection circuit comprises a first signal adjusting module, a detection module and a control module. The first signal adjusting module is used for receiving a first differential signal sent by a motor encoder and adjusting the first differential signal to obtain a second differential signal. The detection module is connected with the first signal adjusting module and is used for detecting the second differential signal to obtain a single-end detection signal used for judging whether the first differential signal appears wire breakage or synchronization.

2. The signal detection circuit of claim 1, wherein, The control module is used for acquiring the single-end detection signal and controlling the motor to stop running when it is determined according to the single-end detection signal that the first differential signal appears wire breakage or synchronization. The signal detection circuit further comprises a signal conversion module which is arranged between the first signal adjusting module and the control module and is used for converting the second differential signal into a single-end control signal and sending the single-end control signal to the control module.

3. The signal detection circuit of claim 2, wherein, The control module is further used for acquiring the single-end control signal and controlling the working state of the motor according to the single-end control signal when it is determined according to the single-end detection signal that the first differential signal does not appear wire breakage or synchronization.

4. The signal detection circuit of claim 2, wherein, The signal detection circuit further comprises a second signal adjusting module which is arranged between the signal conversion module and the control module and is used for signal shaping the single-end control signal to obtain a motor control signal and sending the motor control signal to the control module so that the control module controls the working state of the motor according to the motor control signal. The first signal adjusting module comprises at least one of the following: A first resistor and a first capacitor which are connected in parallel between a first signal line and a first reference power supply, a first signal input end of the signal conversion module and a first signal input end of the detection module are both connected to the first signal line; A second resistor and a second capacitor which are connected in parallel between the first signal line and a second signal line, a first signal input end of the signal conversion module and a first signal input end of the detection module are both connected to the first signal line, a second signal input end of the signal conversion module and a second signal input end of the detection module are both connected to the second signal line; 5. The signal detection circuit of claim 1, wherein, A third resistor and a third capacitor which are connected in parallel between the second signal line and a reference ground, a second signal input end of the signal conversion module and a second signal input end of the detection module are both connected to the second signal line. The detection module comprises a fourth capacitor, a fourth resistor, a fifth resistor and a comparator, the fourth capacitor is connected between a first comparison input end and a second comparison input end of the comparator, one end of the fourth capacitor is connected with a first reference power supply through the fourth resistor, the other end of the fourth capacitor is connected with a reference ground through the fifth resistor, the first comparison input end and the second comparison input end of the comparator are used for receiving the second differential signal, and an output end of the comparator is used for outputting the single-end detection signal.

6. The signal detection circuit of claim 5, wherein, The detection module further comprises a rectifier bridge, a sixth resistor and a seventh resistor, the rectifier bridge comprises a first input end, a second input end, a first output end and a second output end, the first input end of the rectifier bridge is connected with the first signal output end of the first signal adjustment module through the sixth resistor, the second input end of the rectifier bridge is connected with the second signal output end of the first signal adjustment module through the seventh resistor, the first output end of the rectifier bridge is connected between the fourth resistor and the fourth capacitor, and the second output end of the rectifier bridge is connected between the fifth resistor and the fourth capacitor.

7. The signal detection circuit according to claim 3, wherein: The second signal adjustment module comprises a Schmitt trigger, a signal input end of the Schmitt trigger is connected with the output end of the signal conversion module, a signal output end of the Schmitt trigger is connected with the control module, a bias end of the Schmitt trigger is connected with a second reference power supply, and a ground end of the Schmitt trigger is connected with a reference ground.

8. A signal detection method, characterized by, The signal detection circuit is applied to signal detection, and the signal detection circuit comprises a first signal adjustment module and a detection module, the first signal adjustment module is connected with the detection module. The method comprises: obtaining a single-end detection signal sent by the detection module, wherein the single-end detection signal is obtained by detecting a second differential signal sent by the first signal adjustment module, and the second differential signal is obtained by adjusting and processing a first differential signal sent by a motor encoder by the first signal adjustment module; determining whether the first differential signal appears a wire breakage or synchronization according to the single-end detection signal, and controlling the motor to stop running when it is determined that the first differential signal appears a wire breakage or synchronization according to the single-end detection signal.

9. The signal detection method of claim 8, wherein, The method of determining whether the first differential signal appears a wire breakage or synchronization according to the single-end detection signal comprises: when a voltage amplitude of the single-end detection signal is equal to a first preset amplitude, it is determined that the first differential signal appears a wire breakage or synchronization; when the voltage amplitude of the single-end detection signal is equal to a second preset amplitude, it is determined that the first differential signal does not appear a wire breakage or synchronization; wherein the second preset amplitude is greater than the first preset amplitude.

10. The signal detection method of claim 8, wherein, The signal detection circuit further comprises a signal conversion module, and the signal conversion module is arranged between the first signal adjustment module and the control module. The method further comprises: obtaining the single-end control signal sent by the signal conversion module, wherein the single-end control signal is obtained by signal conversion of the second differential signal sent by the first signal adjustment module by the signal conversion module; controlling the working state of the motor according to the single-end control signal when it is determined that the first differential signal does not appear a wire breakage or synchronization according to the single-end detection signal.

11. A servo driver, characterized by comprising: The signal detection circuit comprises any one of claims 1 to 7. The signal detection circuit comprises any one of claims 1 to 7.

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