Driver overcurrent protection circuit, driver overcurrent protection device and robot

Abstract

The utility model belongs to the technical field of robots, and provides a driver overcurrent protection circuit, a driver overcurrent protection device and a robot. A current sampling module is used for sampling current on a main loop power bus of a driver to obtain a current sampling signal; and the differential amplification module performs center voltage bias and signal amplification processing on the current sampling signal so as to obtain a differential amplification signal after center voltage bias. The voltage comparison module compares the differential amplification signal with a preset threshold voltage range and outputs an over-current protection signal when the differential amplification signal exceeds the preset threshold voltage range, and the master control module controls the driver to enter an over-current protection state according to the over-current protection signal. Therefore, hardware overcurrent protection action can be completed in time when overcurrent is caused by faults of the driver, the driver is prevented from being damaged, and the stability and reliability of the robot are improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of robots, and particularly relates to a driver overcurrent protection circuit, a driver overcurrent protection device and a robot. BACKGROUND

[0002] Driver short-circuit overcurrent protection is an important part of ensuring product reliability. However, in current hardware design, phase current resistance sampling has a small detection fault coverage range, such as a part of the bridge arm short circuit, which cannot be detected, and at the same time, software current sampling calculation control and short-circuit protection function need to be considered, so the current sampling range is large and the precision is poor, thereby affecting the control performance of the driver and the accuracy of the current protection point. CONTENT OF THE UTILITY MODEL

[0003] In order to solve the above technical problems, the embodiments of the application provide a driver overcurrent protection circuit, a driver overcurrent protection device and a robot, which aim to improve the response speed and reliability of overcurrent protection monitoring.

[0004] The first aspect of the embodiments of the application provides a driver overcurrent protection circuit, which comprises:

[0005] A current sampling module connected in series with a main loop power bus of a driver, used for sampling a current on the main loop power bus to obtain a current sampling signal;

[0006] A differential amplification module connected with the current sampling module, used for receiving the current sampling signal and performing center voltage biasing and signal amplification processing on the current sampling signal to obtain a differential amplification signal after center voltage biasing;

[0007] A voltage comparison module connected with the differential amplification module, used for comparing the differential amplification signal with a preset threshold voltage range, and outputting an overcurrent protection signal in the case that the differential amplification signal exceeds the preset threshold voltage range;

[0008] A main control module connected with the voltage comparison module and the driver, used for receiving the overcurrent protection signal and controlling the driver to enter an overcurrent protection state according to the overcurrent protection signal.

[0009] In some embodiments, the current sampling module comprises:

[0010] A bus current sampling unit connected between a negative electrode of the driver and a ground wire, used for sampling a current flowing through the driver to obtain the current sampling signal; the current sampling signal comprises a first sampling signal and a second sampling signal.

[0011] In some embodiments, the differential amplification module comprises:

[0012] a center biasing unit, connected with the bus current sampling unit, configured to perform center voltage biasing processing on the first sampling signal and the second sampling signal according to a first preset reference voltage to obtain a differential signal;

[0013] an operational amplification unit, connected with the center biasing unit, configured to perform amplification processing on the differential signal to obtain the differential amplification signal.

[0014] In some embodiments, the differential amplification module further comprises:

[0015] a filtering unit, connected with the operational amplification unit and the voltage comparison module, configured to perform filtering processing on the differential amplification signal and output the differential amplification signal to the voltage comparison module.

[0016] In some embodiments, the voltage comparison module comprises:

[0017] a threshold voltage setting unit, configured to set an upper threshold voltage and a lower threshold voltage of the preset threshold voltage range according to a second preset reference voltage;

[0018] a first voltage comparison unit, connected with the threshold voltage setting unit and the master control module, configured to perform voltage comparison between the differential amplification signal and the upper threshold voltage to obtain a first voltage comparison signal;

[0019] a second voltage comparison unit, connected with the threshold voltage setting unit and the master control module, configured to perform voltage comparison between the differential amplification signal and the lower threshold voltage to obtain a second voltage comparison signal;

[0020] The master control module determines the overcurrent protection signal according to the first voltage comparison signal and the second voltage comparison signal.

[0021] In some embodiments, the differential amplification module further comprises:

[0022] a voltage follower unit, configured to adjust the first preset reference voltage according to the second preset reference voltage.

[0023] In some embodiments, the driver comprises a first bridge arm, a second bridge arm and a third bridge arm, and the master control module is configured to adjust switching duty cycles of the first bridge arm, the second bridge arm and the third bridge arm according to the overcurrent protection signal.

[0024] In some embodiments, the master control module is further configured to sample currents flowing through the first bridge arm, the second bridge arm and the third bridge arm, and adjust switching duty cycles of the first bridge arm, the second bridge arm and the third bridge arm according to the sampled currents.

[0025] The second aspect of the embodiment of the present application further provides a driver overcurrent protection device, the driver overcurrent protection device comprising: a driver, and the driver overcurrent protection circuit according to any one of the above embodiments.

[0026] The third aspect of the embodiment of the present application further provides a robot, the robot comprising: a driver, and the driver overcurrent protection circuit according to any one of the above embodiments.

[0027] The beneficial effects of the embodiment of the present application are as follows: the current sampling module samples the current on the main loop power bus of the driver to obtain a current sampling signal, the differential amplification module performs center voltage biasing and signal amplification processing on the current sampling signal to obtain a differential amplification signal after center voltage biasing. The voltage comparison module compares the differential amplification signal with a preset threshold voltage range, and outputs an overcurrent protection signal in the case that the differential amplification signal exceeds the preset threshold voltage range, and the main control module controls the driver to enter an overcurrent protection state according to the overcurrent protection signal, thereby ensuring that the driver completes a hardware overcurrent protection action in time when overcurrent occurs due to a fault, avoiding damage to the driver, and improving the stability and reliability of the robot. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a circuit structure schematic of a driver overcurrent protection circuit provided by an embodiment of the present application Figure 1 ;

[0029] Figure 2 is a circuit structure schematic of a driver overcurrent protection circuit provided by an embodiment of the present application Figure 2 ;

[0030] Figure 3 is a circuit structure schematic of a driver overcurrent protection circuit provided by an embodiment of the present application Figure 3 ;

[0031] Figure 4 is a circuit structure schematic of a driver overcurrent protection circuit provided by an embodiment of the present application Figure 4 ;

[0032] Figure 5 is a circuit structure schematic of a driver overcurrent protection circuit provided by an embodiment of the present application Figure 5 ;

[0033] Figure 6 is a circuit structure schematic of a driver overcurrent protection circuit provided by an embodiment of the present application Figure 6 ;

[0034] Figure 7 is a circuit structure schematic of a driver provided by an embodiment of the present application

[0035] Figure 8 FIG. 8 is a schematic diagram of a circuit structure of a differential amplification module according to an embodiment of the present application;

[0036] Figure 9 FIG. 9 is a schematic diagram of a circuit structure of a voltage comparison module according to an embodiment of the present application;

[0037] Figure 10 FIG. 10 is a schematic diagram of a circuit structure of a voltage follower unit according to an embodiment of the present application. DETAILED DESCRIPTION

[0038] In order to make the technical problems solved by the present application, the technical solutions and the beneficial effects clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and should not be used to limit the present application.

[0039] It should be noted that when an element is referred to as being "fixed" or "set" on another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or indirectly connected to the other element.

[0040] It should be understood that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0041] In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is one or more than one, unless otherwise specifically limited.

[0042] In the current overcurrent protection scheme, the phase current resistance sampling has a small fault detection coverage, such as a part of the bridge arm through cannot be detected, and at the same time needs to consider the software current sampling calculation control and the implementation of the short circuit protection function, so the current sampling range is large and the precision is poor, thereby affecting the control performance of the driver and the accuracy of the current protection point. The power tube voltage drop detection scheme is greatly affected by other factors, such as temperature rise will affect the internal resistance of the power tube and cause the voltage drop to change, so it is difficult to accurately reflect the relationship between the current and the voltage drop, and the device integration of this scheme is high and the cost is also high.

[0043] To solve the above technical problems, the embodiment of the application provides a driver overcurrent protection circuit, referring to Figure 1 The driver overcurrent protection circuit includes: a current sampling module 200, a differential amplification module 300, a voltage comparison module 400, and a main control module 500. The current sampling module 200 is connected in series to the main loop power bus of the driver 100, and is used to sample the current on the main loop power bus to obtain a current sampling signal. The differential amplification module 300 is connected with the current sampling module 200, and is used to receive the current sampling signal, and to perform center voltage bias processing on the current sampling signal to obtain a differential signal, and to perform signal amplification processing on the differential signal to obtain a differential amplification signal. The voltage comparison module 400 is connected with the differential amplification module 300, and is used to compare the differential amplification signal with a preset threshold voltage range, and to output an overcurrent protection signal when the differential amplification signal exceeds the preset threshold voltage range. The main control module 500 is connected with the voltage comparison module 400 and the driver 100, and is used to receive the overcurrent protection signal, and to control the driver 100 to enter an overcurrent protection state according to the overcurrent protection signal.

[0044] In the embodiment, the current sampling module 200 samples the current on the main loop power bus of the driver 100 to obtain a current sampling signal, the differential amplification module 300 performs center voltage bias processing on the current sampling signal to obtain a differential signal, and the differential signal is amplified to obtain a differential amplification signal. The voltage comparison module 400 compares the differential amplification signal with a preset threshold voltage range, and outputs an overcurrent protection signal when the differential amplification signal exceeds the preset threshold voltage range. The main control module 500 controls the driver 100 to enter an overcurrent protection state according to the overcurrent protection signal, so as to ensure that the driver 100 completes the hardware overcurrent protection action in time when an overcurrent occurs due to a fault, avoids damage to the driver 100, and improves the stability and reliability of the robot. The overcurrent protection design scheme in the embodiment has the characteristics of few devices, low cost, high reliability, fast response speed, and certain design flexibility. It only needs to calculate and adjust the corresponding sampling resistance value, operational amplifier gain resistance parameter, and overcurrent point setting resistance parameter according to product requirements, and can be transplanted and applied to the servo driver 100 of different power levels of the robot joint. At the same time, the protection scheme is purely realized based on hardware circuit and does not depend on software, so when a large current fault such as bridge arm shoot-through or motor interphase short circuit occurs, the protection can be triggered in time and effectively, and the robot joint servo driver 100 is prevented from being damaged.

[0045] In some embodiments, referring to FIG. 2, Figure 2 As shown in FIG. 2, the current sampling module 200 includes a bus current sampling unit 210 connected between the negative electrode of the driver 100 and the ground wire. The bus current sampling unit 210 is configured to sample the current flowing through the driver 100 to obtain a current sampling signal.

[0046] In the embodiment, the positive electrode of the driver 100 is connected to the positive electrode of the power supply VIN, and the bus current sampling unit 210 is connected in series between the negative electrode of the driver 100 and the ground wire GND. In this way, the current flowing through the driver 100 can be converted into a corresponding current sampling signal.

[0047] In some embodiments, the current sampling signal includes a first sampling signal and a second sampling signal, and the first sampling signal and the second sampling signal are output from both ends of the bus current sampling unit 210.

[0048] In some embodiments, the bus current sampling unit 210 can be a sampling resistor, and the resistance value of the sampling resistor is in the order of milliohms. In this way, the current flowing through the driver 100 can be sampled by a hardware scheme, and the corresponding first sampling signal and second sampling signal can be obtained by differential wiring from both ends of the sampling resistor. The resistance value of the sampling resistor in the embodiment can be set according to the current sampling range, power loss, and operational amplifier ratio of the differential amplification module 300.

[0049] In some embodiments, referring to Figure 3 As shown, the differential amplification module 300 comprises a center bias unit 310 and an operational amplification unit 320. The center bias unit 310 is connected with the bus current sampling unit 210, and is configured to perform center voltage bias processing on the first sampling signal and the second sampling signal according to a first preset reference voltage to obtain a differential signal. The operational amplification unit 320 is connected with the center bias unit 310, and is configured to perform amplification processing on the differential signal to obtain a differential amplification signal.

[0050] In this embodiment, the center bias unit 310 is configured to perform center voltage bias processing on the first sampling signal and the second sampling signal according to the first preset reference voltage to obtain a pair of differential signals. The output signal of the bus current sampling unit 210 is centered on the first preset reference voltage, and the positive and negative currents are symmetrically arranged above and below the first preset reference voltage. The pair of differential signals are output to the non-inverting input terminal and the inverting input terminal of the operational amplification unit 320 for differential amplification, and the corresponding differential amplification signal is obtained. In this embodiment, the center bias unit 310 is configured to perform center voltage bias processing on the first sampling signal and the second sampling signal according to the first preset reference voltage, so that the fluctuation range of the differential signal can be flexibly adjusted, and the overcurrent protection point can be flexibly set according to the power and performance of the driver 100. The overcurrent scheme can be adjusted in time according to the application scenario or working mode of the driver 100.

[0051] In some embodiments, referring to Figure 4 As shown, the differential amplification module 300 further comprises a filtering unit 330. The filtering unit 330 is connected with the operational amplification unit 320 and the voltage comparison module 400, and is configured to perform filtering processing on the differential amplification signal and output the differential amplification signal to the voltage comparison module 400.

[0052] In this embodiment, the filtering unit 330 can perform filtering processing on the differential amplification signal and output the differential amplification signal to the voltage comparison module 400.

[0053] In some embodiments, referring to Figure 5As shown, the voltage comparison module 400 comprises: a threshold voltage setting unit 410, a first voltage comparison unit 420, and a second voltage comparison unit 430. The threshold voltage setting unit 410 is configured to set an upper threshold voltage and a lower threshold voltage of a preset threshold voltage range according to a second preset reference voltage. The first voltage comparison unit 420 is connected to the threshold voltage setting unit 410 and the master control module. The first voltage comparison unit 420 is configured to perform voltage comparison between the differential amplification signal and the upper threshold voltage, and obtain a first voltage comparison signal. The second voltage comparison unit 430 is connected to the threshold voltage setting unit 410 and the master control module. The second voltage comparison unit 430 is configured to perform voltage comparison between the differential amplification signal and the lower threshold voltage, and obtain a second voltage comparison signal. The master control module 500 determines the overcurrent protection signal according to the first voltage comparison signal and the second voltage comparison signal.

[0054] In this embodiment, the threshold voltage setting unit 410 sets the upper threshold voltage and the lower threshold voltage of the preset threshold voltage range according to the second preset reference voltage. The first voltage comparison unit 420 performs voltage comparison between the differential amplification signal and the upper threshold voltage, and obtains the first voltage comparison signal. The second voltage comparison unit 430 performs voltage comparison between the differential amplification signal and the lower threshold voltage, and obtains the second voltage comparison signal. The master control module 500 determines the voltage interval of the differential amplification signal according to the levels of the first voltage comparison signal and the second voltage comparison signal, thereby determining whether the differential amplification signal exceeds the preset threshold interval, i.e., whether the differential amplification signal exceeds the preset threshold voltage range, and generating the overcurrent protection signal in the case where the differential amplification signal exceeds the preset threshold voltage range. In this way, the overcurrent reaction speed can be improved by means of hardware, and the hardware overcurrent protection of the driver 100 is completed.

[0055] In some embodiments, the threshold voltage setting unit 410 performs voltage division on the second preset reference voltage, thereby obtaining the upper threshold voltage and the lower threshold voltage. The upper threshold voltage is greater than the lower threshold voltage, and the voltage thereof can be determined by the resistance ratio of the voltage division resistor.

[0056] In some embodiments, referring to Figure 6 As shown, the differential amplification module 300 further comprises a voltage follower unit 340. The voltage follower unit 340 is configured to adjust the first preset reference voltage according to the second preset reference voltage.

[0057] In this embodiment, the voltage follower unit 340 can establish linkage adjustment between the first preset reference voltage and the second preset reference voltage, thereby realizing voltage following and impedance matching between the first preset reference voltage and the second preset reference voltage.

[0058] In some embodiments, referring to Figure 7As shown, the driver 100 includes a first bridge arm 111, a second bridge arm 121, and a third bridge arm 131, and the master control module 500 is configured to adjust the switching duty cycles of the first bridge arm 111, the second bridge arm 121, and the third bridge arm 131 according to the overcurrent protection signal.

[0059] In this embodiment, the first ends of the first bridge arm 111, the second bridge arm 121, and the third bridge arm 131 are connected to the positive electrode VIN of the power supply, and the second ends of the first bridge arm 111, the second bridge arm 121, and the third bridge arm 131 are connected to the ground GND via the bus current sampling unit 210. The master control module 500 can adjust the switching duty cycles of the first bridge arm 111, the second bridge arm 121, and the third bridge arm 131 according to the overcurrent protection signal, so as to control the forced turn-off of the first bridge arm 111, the second bridge arm 121, and the third bridge arm 131 in the case of overcurrent of the driver 100, thereby preventing damage to the driver 100. Moreover, the driver overcurrent protection circuit can be implemented by a pure hardware circuit, and has the characteristics of fast response speed and high reliability.

[0060] In some embodiments, in combination with Figure 7 As shown, the first bridge arm 111 includes a first switch Q1 and a second switch Q2. The first end of the first switch Q1 is connected to the positive electrode VIN of the power supply, and the second end of the first switch Q1 and the first end of the second switch Q2 are connected to the first-phase current output terminal U2. The second end of the second switch Q2 is connected to the ground GND via the bus current sampling unit 210.

[0061] In some embodiments, in combination with Figure 7 As shown, the second bridge arm 121 includes a third switch Q3 and a fourth switch Q4. The first end of the third switch Q3 is connected to the positive electrode VIN of the power supply, and the second end of the third switch Q3 and the first end of the fourth switch Q4 are connected to the second-phase current output terminal V2. The second end of the fourth switch Q4 is connected to the ground GND via the bus current sampling unit 210.

[0062] In some embodiments, in combination with Figure 7 As shown, the third bridge arm 131 includes a fifth switch Q5 and a sixth switch Q6. The first end of the fifth switch Q5 is connected to the positive electrode VIN of the power supply, and the second end of the fifth switch Q5 and the first end of the sixth switch Q6 are connected to the third-phase current output terminal W2. The second end of the sixth switch Q6 is connected to the ground GND via the bus current sampling unit 210.

[0063] In some embodiments, the bus current sampling unit 210 includes a sampling resistor R0.

[0064] In some embodiments, the second ends of the first bridge arm 111, the second bridge arm 121 and the third bridge arm 131 are connected to a reference ground potential PGND, and the reference ground potential PGND can be grounded via a capacitor.

[0065] In some embodiments, the first bridge arm 111, the second bridge arm 121 and the third bridge arm 131 are connected to the reference ground potential PGND. Figure 7 As shown, the driver 100 further includes a first driving unit 112 and a second driving unit 113, the first driving unit 112 being connected between the master control module 500 and the first switch tube Q1, and the second driving unit 113 being connected between the master control module 500 and the second switch tube Q2, the first driving unit 112 being capable of generating a first driving signal according to a first switch control signal provided by the master control module 500 to control the switching duty cycle of the first switch tube Q1, and the second driving unit 113 being capable of generating a second driving signal according to a second switch control signal provided by the master control module 500 to control the switching duty cycle of the second switch tube Q2.

[0066] In some embodiments, the first bridge arm 111, the second bridge arm 121 and the third bridge arm 131 are connected to the reference ground potential PGND. Figure 7 As shown, the driver 100 further includes a third driving unit 122 and a fourth driving unit 123, the third driving unit 122 being connected between the master control module 500 and the third switch tube Q3, and the fourth driving unit 123 being connected between the master control module 500 and the fourth switch tube Q4, the third driving unit 122 being capable of generating a third driving signal according to a third switch control signal provided by the master control module 500 to control the switching duty cycle of the third switch tube Q3, and the fourth driving unit 123 being capable of generating a fourth driving signal according to a fourth switch control signal provided by the master control module 500 to control the switching duty cycle of the fourth switch tube Q4.

[0067] In some embodiments, the first bridge arm 111, the second bridge arm 121 and the third bridge arm 131 are connected to the reference ground potential PGND. Figure 7 As shown, the driver 100 further includes a fifth driving unit 132 and a sixth driving unit 133, the fifth driving unit 132 being connected between the master control module 500 and the fifth switch tube Q5, and the sixth driving unit 133 being connected between the master control module 500 and the sixth switch tube Q6, the fifth driving unit 132 being capable of generating a fifth driving signal according to a fifth switch control signal provided by the master control module 500 to control the switching duty cycle of the fifth switch tube Q5, and the sixth driving unit 133 being capable of generating a sixth driving signal according to a sixth switch control signal provided by the master control module 500 to control the switching duty cycle of the sixth switch tube Q6.

[0068] In some embodiments, the master control module 500 is further configured to sample the current flowing through the first bridge arm 111, the second bridge arm 121 and the third bridge arm 131, and adjust the switching duty cycles of the first bridge arm 111, the second bridge arm 121 and the third bridge arm 131 according to the sampled current.

[0069] In some embodiments, the first bridge arm 111, the second bridge arm 121 and the third bridge arm 131 are connected to the reference ground potential PGND. Figure 7As shown, the first bridge arm 111 is connected in series with a first sampling resistor Rs1, and the current flowing through the first bridge arm 111 is sampled, and the sampling result is output to the main control module 500.

[0070] In some embodiments, in combination with Figure 7 As shown, the second bridge arm 121 is connected in series with a second sampling resistor Rs2, and the current flowing through the second bridge arm 121 is sampled, and the sampling result is output to the main control module 500.

[0071] In some embodiments, in combination with Figure 7 As shown, the third bridge arm 131 is connected in series with a third sampling resistor Rs3, and the current flowing through the third bridge arm 131 is sampled, and the sampling result is output to the main control module 500.

[0072] In some embodiments, in combination with Figure 7 As shown, the first driving unit 112 includes a first resistor R1, a second resistor R2, a third resistor R3, a first diode D1, a second diode D2, a first capacitor C1, a first end of the first resistor R1 and a cathode of the first diode D1 are connected to a first control end GHU of the main control module 500, an anode of the first diode D1 is connected to a first end of the second resistor R2, a second end of the second resistor R2, a second end of the first resistor R1, a cathode of the second diode D2, a first end of the third resistor R3 and a first end of the first capacitor C1 are connected to a control end of the first switch tube Q1, an anode of the second diode D2, a second end of the third resistor R3 and a second end of the first capacitor C1 are connected to a first feedback end U1, and the first feedback end U1 can be connected to a first phase current output end U2.

[0073] In some embodiments, in combination with Figure 7 As shown, the second driving unit 113 includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a third diode D3, a fourth diode D4, a second capacitor C2, a first end of the fourth resistor R4 and a cathode of the third diode D3 are connected to a second control end GLU of the main control module 500, an anode of the third diode D3 is connected to a first end of the fifth resistor R5, a second end of the fifth resistor R5, a second end of the fourth resistor R4, a cathode of the fourth diode D4, a first end of the sixth resistor R6 and a first end of the second capacitor C2 are connected to a control end of the second switch tube Q2, an anode of the fourth diode D4, a second end of the sixth resistor R6 and a second end of the second capacitor C2 are connected to a positive sampling end ISE_U+ of the first sampling resistor Rs1.

[0074] In some embodiments, in combination with Figure 7As shown, the third driving unit 122 includes a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a fifth diode D5, a sixth diode D6, and a third capacitor C3. The first end of the seventh resistor R7 and the cathode of the fifth diode D5 are connected to the third control end GHV of the master control module 500, the anode of the fifth diode D5 is connected to the first end of the eighth resistor R8, the second end of the seventh resistor R7, the second end of the eighth resistor R8, the cathode of the sixth diode D6, the first end of the ninth resistor R9, and the first end of the third capacitor C3 are connected to the control end of the third switch tube Q3, the anode of the sixth diode D6, the second end of the ninth resistor R9, and the second end of the third capacitor C3 are connected to the second feedback end V1, and the second feedback end V1 can be connected to the second phase current output end V2.

[0075] In some embodiments, in combination with Figure 7 As shown, the fourth driving unit 123 includes a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a seventh diode D7, an eighth diode D8, and a fourth capacitor C4. The first end of the tenth resistor R10 and the cathode of the seventh diode D7 are connected to the fourth control end GLV of the master control module 500, the anode of the seventh diode D7 is connected to the first end of the eleventh resistor R11, the second end of the eleventh resistor R11, the second end of the tenth resistor R10, the cathode of the eighth diode D8, the first end of the fourth capacitor C4, and the first end of the twelfth resistor R12 are connected to the control end of the fourth switch tube Q4, the anode of the eighth diode D8, the second end of the twelfth resistor R12, and the second end of the fourth capacitor C4 are connected to the positive sampling end ISE_V+ of the second sampling resistor Rs2.

[0076] In some embodiments, in combination with Figure 7 As shown, the fifth driving unit 132 includes a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a ninth diode D9, a twelfth diode D10, and a fifth capacitor C5. The cathode of the ninth diode D9 and the first end of the thirteenth resistor R13 are connected to the fifth control end GHW of the master control module 500, the second end of the thirteenth resistor R13, the second end of the fourteenth resistor R14, the cathode of the twelfth diode D10, and the first end of the fifth capacitor C5 are connected to the control end of the fifth switch tube Q5, the anode of the twelfth diode D10, the second end of the fifteenth resistor R15, and the second end of the fifth capacitor C5 are connected to the third feedback end W1, and the third feedback end W1 can be connected to the third phase current output end W2.

[0077] In some embodiments, in combination with Figure 8As shown, the sixth driving unit 133 includes a sixteenth resistor R16, a seventeenth resistor R17, an eighteenth resistor R18, an eleventh diode D11, a twelfth diode D12, and a sixth capacitor C6. The first end of the sixteenth resistor R16 and the cathode of the eleventh diode D11 are connected to the sixth control end GLW of the master control module 500, the first end of the seventeenth resistor R17 is connected to the anode of the eleventh diode D11, the second end of the sixteenth resistor R16, the second end of the seventeenth resistor R17, the cathode of the twelfth diode D12, the first end of the eighteenth resistor R18, and the first end of the sixth capacitor C6 are connected to the control end of the sixth switch tube Q6, and the anode of the twelfth diode D12, the second end of the eighteenth resistor R18, and the second end of the sixth capacitor C6 are connected to the positive sampling end ISE_W+ of the third sampling resistor Rs3.

[0078] In some embodiments, in combination with Figure 8 As shown, the center biasing unit 310 includes a twentieth resistor R20, a twenty-first resistor R21, a twenty-second resistor R22, and a seventh capacitor C7. The first end of the twentieth resistor R20 is connected to the first end of the bus current sampling unit 210 as the positive input end IBUS+ of the center biasing unit 310, the first end of the twenty-first resistor R21 is connected to the second end of the bus current sampling unit 210 as the negative input end IBUS- of the center biasing unit 310, the second ends of the twentieth resistor R20 and the twenty-first resistor R21 are respectively connected to the two ends of the seventh capacitor C7, the first end of the twentieth resistor R20 and the first end of the twenty-second resistor R22 are connected to the non-inverting input end of the operational amplifying unit 320, and the second end of the twenty-second resistor R22 is connected to the first reference voltage end VREF1.

[0079] In this embodiment, the first sampling signal and the second sampling signal are respectively input to the two ends of the seventh capacitor C7, and the first reference voltage end VREF1 provides a first preset reference voltage as a center reference voltage, and the first sampling signal and the second sampling signal are subjected to center voltage biasing processing to obtain a pair of differential signals, which are respectively output to the non-inverting input end and the inverting input end of the operational amplifying unit 320 for differential amplification to obtain corresponding differential amplification signals. In this embodiment, the center biasing unit 310 is used to subject the first sampling signal and the second sampling signal to center voltage biasing processing according to the first preset reference voltage, so that the fluctuation interval of the differential signal can be flexibly adjusted, and the overcurrent protection point can be flexibly set according to the power and performance of the driver 100, and the overcurrent scheme can be adjusted in time according to the application scenario or working mode of the driver 100.

[0080] In some embodiments, in combination with Figure 8As shown, the operational amplification unit 320 includes an operational amplifier U11, an eighth capacitor C8, and a nineteenth resistor R19. The non-inverting input pin of the operational amplifier U11 is connected to the second end of a twentieth resistor R20, the inverting input pin of the operational amplifier U11 is connected to the second end of a twenty-first resistor R21, and the inverting input pin of the operational amplifier U11 is connected to the output pin of the operational amplifier U11 via the nineteenth resistor R19. The positive power supply pin of the operational amplifier U11 is connected to the first end of the eighth capacitor C8, and the second end of the eighth capacitor C8 is grounded. The negative power supply pin of the operational amplifier U11 is grounded.

[0081] In this embodiment, the operational amplifier U11, the eighth capacitor C8, and the nineteenth resistor R19 form a negative feedback operational amplification circuit, which differentially amplifies the differential signal to obtain a corresponding differential amplified signal.

[0082] In some embodiments, in combination with Figure 9 As shown, the filter unit 330 includes a ninth capacitor C9 and a twenty-third resistor R23. The first end of the twenty-third resistor R23 is connected to the output pin of the operational amplifier U11, and the second end of the twenty-third resistor R23 and the first end of the ninth capacitor C9 are connected to the input terminal IBUS_ADC of the voltage comparison module 400. The second end of the ninth capacitor C9 is grounded.

[0083] In this embodiment, the ninth capacitor C9 and the twenty-third resistor R23 form an RC circuit, which filters and outputs the differential amplified signal to the voltage comparison module 400.

[0084] In some embodiments, in combination with Figure 9 As shown, the threshold voltage setting unit 410 includes a twenty-fourth resistor R24, a twenty-fifth resistor R25, a twenty-sixth resistor R26, a tenth capacitor C10, and an eleventh capacitor C11. The twenty-fourth resistor R24, the twenty-fifth resistor R25, and the twenty-sixth resistor R26 are connected in series between the second reference voltage terminal VREF2 and ground. The common node of the twenty-fourth resistor R24 and the twenty-fifth resistor R25 and the first end of the tenth capacitor C10 are connected to the second reference voltage node VREF_OC2, which is connected to the non-inverting input terminal of the second voltage comparison unit 430. The common node of the twenty-fifth resistor R25 and the twenty-sixth resistor R26 and the first end of the eleventh capacitor C11 are connected to the first reference voltage node VREF_OC1, which is connected to the inverting input terminal of the first voltage comparison unit 420. The second end of the tenth capacitor C10 and the second end of the eleventh capacitor C11 are grounded.

[0085] In the embodiment, the twenty-fourth resistor R24, the twenty-fifth resistor R25 and the twenty-sixth resistor R26 are connected in series to form a voltage dividing circuit, and the upper threshold voltage and the lower threshold voltage of the preset threshold voltage range are obtained by dividing the second preset reference voltage provided by the second reference voltage terminal VREF2.

[0086] In some embodiments, the non-inverting input terminal of the first voltage comparison unit 420 and the inverting input terminal of the second voltage comparison unit 430 are connected to the input terminal IBUS_ADC of the voltage comparison module 400.

[0087] In some embodiments, the first voltage comparison unit 420 includes a first voltage comparator U2B, a twenty-seventh resistor R27 and a twenty-eighth resistor R28, as shown in FIG. 4B. Figure 9 The output terminal of the first voltage comparator U2B, the first terminal of the twenty-seventh resistor R27 and the first terminal of the twenty-eighth resistor R28 are connected together, the second terminal of the twenty-seventh resistor R27 is connected to the second power supply terminal, and the second terminal of the twenty-eighth resistor R28 is connected to the first comparison signal output terminal IBUS_OC1 of the master control module 500.

[0088] In some embodiments, the second voltage comparison unit 430 includes a second voltage comparator U2A, a twenty-ninth resistor R29, a thirtieth resistor R30 and a twelfth capacitor C12, as shown in FIG. 4C. Figure 10 The output terminal of the second voltage comparator U2A, the first terminal of the twenty-ninth resistor R29 and the first terminal of the thirtieth resistor R30 are connected together, the second terminal of the twenty-ninth resistor R29 is connected to the second power supply terminal, and the second terminal of the thirtieth resistor R30 is connected to the second comparison signal output terminal IBUS_OC2 of the master control module 500.

[0089] In some embodiments, the second voltage comparison unit 430 includes a second voltage comparator U2A, a twenty-ninth resistor R29, a thirtieth resistor R30 and a twelfth capacitor C12, as shown in FIG. 4C. ​As shown, the voltage follower unit 340 includes an operational amplifier chip U3, a thirtieth resistor R30, a thirty-first resistor R31, a thirteenth capacitor C13, an output pin OUTD and an inverting input pin -inD of the operational amplifier chip U3 are connected to the first reference voltage terminal VREF1, a non-inverting input pin +inD of the operational amplifier chip U3, a first end of the thirtieth resistor R30 and a first end of the thirty-first resistor R31 are connected, a second end of the thirtieth resistor R30 and a first end of the thirteenth capacitor C13 are connected to the second reference voltage terminal VREF2, and a second end of the thirty-first resistor R31 and a second end of the thirteenth capacitor C13 are grounded.

[0090] In this embodiment, the second preset reference voltage provided by the second reference voltage terminal VREF2 is subjected to voltage division processing by the voltage division circuit composed of the thirtieth resistor R30 and the thirty-first resistor R31 to obtain a corresponding voltage division, and the voltage division is used as the input voltage of the operational amplifier chip U3, and the first preset reference voltage output by the operational amplifier chip U3 is output to the first reference voltage terminal VREF1, so that the linkage adjustment between the first preset reference voltage and the second preset reference voltage is established, and the voltage following and impedance matching between the first preset reference voltage and the second preset reference voltage are realized.

[0091] The embodiment of the present application also provides a driver overcurrent protection device, which comprises the driver overcurrent protection circuit according to any one of the above embodiments.

[0092] In this embodiment, the driver can drive at least one motor, and by controlling the driver overcurrent protection circuit, the corresponding threshold value can be adjusted according to the application environment requirement of the motor, so that the driver overcurrent protection circuit can be transplanted into a servo driver of different power levels of a robot joint, has the characteristics of few devices, low cost, high reliability, fast response speed and the like, and has certain design flexibility.

[0093] The embodiment of the present application also provides a robot, which comprises a driver and the driver overcurrent protection circuit according to any one of the above embodiments.

[0094] In the embodiment, the driver overcurrent protection circuit in the embodiment can be formed by a combination of a milliohm sampling resistor, an operational amplifier and a voltage comparator. The overcurrent protection design scheme in the embodiment has the characteristics of few devices, low cost, high reliability, fast response speed and certain design flexibility. Only the sampling resistor value, the operational amplifier gain resistor parameter and the overcurrent point setting resistor parameter need to be calculated and adjusted according to the product requirements, and the scheme can be transplanted and applied to the servo drivers of different power levels of robot joints. At the same time, the protection scheme is purely realized based on hardware circuit and does not depend on software. Therefore, when a bridge arm shoot-through or a motor inter-phase short circuit occurs, the protection can be triggered in time and effectively to avoid damage to the robot joint servo driver.

[0095] The application has the following beneficial effects: The current sampling module samples the current on the main loop power bus of the driver to obtain a current sampling signal, the differential amplification module performs center voltage biasing and signal amplification processing on the current sampling signal to obtain a differential amplification signal after center voltage biasing. The voltage comparison module compares the differential amplification signal with a preset threshold voltage range and outputs an overcurrent protection signal when the differential amplification signal exceeds the preset threshold voltage range. The main control module controls the driver to enter an overcurrent protection state according to the overcurrent protection signal, thereby ensuring that the driver completes a hardware overcurrent protection action in time when overcurrent occurs due to a fault, avoiding damage to the driver and improving the stability and reliability of the robot.

[0096] In the above embodiments, the description of each embodiment has its own focus. The parts not described or recorded in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0097] The above embodiments are only used to illustrate the technical solutions of the application, rather than limit them. Although the application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements to some technical features. The modifications or replacements do not change the essence of the corresponding technical solutions, and should be included in the protection scope of the application.

Claims

1. A driver overcurrent protection circuit, characterized by, The driver overcurrent protection circuit comprises: a current sampling module connected in series to a main loop power bus of the driver, for sampling a current on the main loop power bus to obtain a current sampling signal; a differential amplification module connected to the current sampling module, for receiving the current sampling signal and performing center voltage biasing and signal amplification processing on the current sampling signal to obtain a center voltage biased differential amplification signal; a voltage comparison module connected to the differential amplification module, for comparing the differential amplification signal with a preset threshold voltage range, and outputting an overcurrent protection signal in a case where the differential amplification signal exceeds the preset threshold voltage range; a master control module connected to the voltage comparison module and the driver, for receiving the overcurrent protection signal and controlling the driver to enter an overcurrent protection state according to the overcurrent protection signal; the driver comprises a first bridge arm, a second bridge arm and a third bridge arm, and the master control module controls the first bridge arm, the second bridge arm and the third bridge arm to be turned off according to the overcurrent protection signal.

2. The driver overcurrent protection circuit of claim 1, wherein, The current sampling module comprises: a bus current sampling unit connected between a negative electrode of the driver and a ground wire, for sampling a current flowing through the driver to obtain the current sampling signal.

3. The driver overcurrent protection circuit of claim 2, wherein, The differential amplification module comprises: a center biasing unit connected to the bus current sampling unit, for performing center voltage biasing processing on a first sampling signal and a second sampling signal according to a first preset reference voltage to obtain a differential signal; the current sampling signal comprises the first sampling signal and the second sampling signal; an operational amplification unit connected to the center biasing unit, for performing amplification processing on the differential signal to obtain the differential amplification signal.

4. The driver overcurrent protection circuit of claim 3, wherein, The differential amplification module further comprises: a filtering unit connected to the operational amplification unit and the voltage comparison module, for performing filtering processing on the differential amplification signal and outputting the differential amplification signal to the voltage comparison module.

5. The driver overcurrent protection circuit of claim 3, wherein, The voltage comparison module comprises: a threshold voltage setting unit for setting an upper threshold voltage and a lower threshold voltage of the preset threshold voltage range according to a second preset reference voltage; a first voltage comparison unit connected to the threshold voltage setting unit and the master control module, for performing voltage comparison between the differential amplification signal and the upper threshold voltage to obtain a first voltage comparison signal; a second voltage comparison unit connected to the threshold voltage setting unit and the master control module, for performing voltage comparison between the differential amplification signal and the lower threshold voltage to obtain a second voltage comparison signal; the master control module determines the overcurrent protection signal according to the first voltage comparison signal and the second voltage comparison signal.

6. The driver overcurrent protection circuit of claim 5, wherein, The differential amplification module further comprises: a voltage follower unit for adjusting the first preset reference voltage according to the second preset reference voltage.

7. The driver overcurrent protection circuit of claim 1, wherein, The master control module is further configured to sample currents flowing through the first bridge arm, the second bridge arm and the third bridge arm, and adjust switching duty cycles of the first bridge arm, the second bridge arm and the third bridge arm according to the sampled currents.

8. A driver overcurrent protection device, characterized by, The drive overcurrent protection device comprises a drive and the drive overcurrent protection circuit as claimed in any one of claims 1 to 7.

9. A robot, characterized in that The robot comprises a drive and the drive overcurrent protection circuit as claimed in any one of claims 1 to 7.

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