Servo driving controller based on resistor current isolation sampling

Abstract

The invention provides a servo driving controller based on resistance current isolation sampling, which comprises an inverter unit, a phase current sampling unit, a current conditioning unit, a main control unit, a rotary transformer demodulation unit, an off-chip AD sampling unit, a gate-level isolation driving unit, a bus voltage acquisition unit, a bus current acquisition unit and a bus current acquisition unit, wherein the inverter unit comprises a switch tube Q1, a switch tube Q2, a switch tube Q3, a switch tube Q4, a switch tube Q5, a switch tube Q6 and a bus support capacitor C1; the phase current sampling unit comprises sampling resistors Rs1, Rs2 and Rs3; the current conditioning unit comprises an LVDS-1 transmitter, an LVDS-2 transmitter, an LVDS-3 transmitter, an isolation type sigma modulator 1, an isolation type sigma modulator 2 and an isolation type sigma modulator 3; the main control unit comprises a sigma filter module and an enhanced pulse width modulator; the bus voltage acquisition unit comprises sampling resistors R2 and R3 and an isolation operational amplifier; the bus current acquisition unit comprises a sampling resistor Rs4 and an isolation operational amplifier.

Description

Technical Field

[0001] The invention belongs to the field of electronic engineering technology, and in particular relates to a servo drive controller based on resistance current isolation sampling. Background Art

[0002] Servo drive system is one of the hot spots in the current research of robotics, especially in the joint drive of humanoid robots. Compared with hydraulic servo system, it has better safety, higher efficiency, more reliability and easier maintenance. One of the technical keys of servo drive system is the design of servo drive controller, which mainly includes the control part of weak current side, signal acquisition part and power inverter part of drive power. The application of inverter in AC transmission system has been very mature, especially in the control of permanent magnet synchronous motor, which mostly adopts three-phase inverter to realize its power inverter function. Since the signal acquisition part needs to realize the signal isolation between weak current control side and power inverter side, Hall current sensor and other solutions are often used. At present, when selecting the servo system of humanoid robot joint drive, volume and weight are the most important factors under the premise of meeting the power requirements, so the miniaturization design of servo drive controller has become the main research hotspot. Summary of the invention

[0003] The purpose of the present invention is to propose a servo drive controller based on resistor current isolation sampling. The three-phase current sampling adopts a precision resistor + isolated △-Σ solution to reduce the hardware size and overhead of the current sampling link. At the same time, the power device adopts a multi-tube parallel solution to achieve the expansion of the capacitor capacity in a small volume and the improvement of the inverter efficiency and energy conversion efficiency. In addition, the power device adopts a surface mount packaging form + aluminum substrate design to further improve the heat dissipation efficiency, reduce the size of the radiator, and achieve the design purpose of miniaturization of the servo drive controller.

[0004] The technical solution of the present invention is: a servo drive controller based on resistance current isolation sampling, the servo drive controller includes an inverter unit, a phase current sampling unit, a current conditioning unit, a main control unit, a resolver demodulation unit, an off-chip AD sampling unit, a gate-level isolation drive unit, a bus voltage acquisition unit, a bus current acquisition unit, and a bus current acquisition unit, wherein:

[0005] The inverter unit includes switch tube Q1, switch tube Q2, switch tube Q3, switch tube Q4, switch tube Q5, switch tube Q6, and bus support capacitor C1; the phase current sampling unit includes sampling resistors Rs1, Rs2, and Rs3; the current conditioning unit includes LVDS-1 transmitter, LVDS-2 transmitter, LVDS-3 transmitter, isolated △-Σ modulator 1, isolated △-Σ modulator 2, and isolated △-Σ modulator 3; the main control unit includes a △-Σ filter module and an enhanced pulse width modulator; the bus voltage acquisition unit includes sampling resistors R2, R3, and an isolated operational amplifier; the bus current acquisition unit includes a sampling resistor Rs4 and an isolated operational amplifier;

[0006] The external input DC bus voltage Udc+ / Udc-, the bus voltage sampling resistors R2 and R3 are connected in series at both ends of the DC bus voltage Udc+ / Udc-, and the voltage u is obtained by voltage division ds , and then sent to the off-chip AD sampling unit through the isolation amplifier; at the same time, the bus current sampling resistor Rs4 is connected in series with the Udc- branch to obtain the bus current i ds The external AD sampling unit is sent through the isolation amplifier; the external AD sampling unit and the resolver demodulation unit are connected to the main control unit through the SPI bus respectively; in addition, the bus support capacitor C1 is connected across the DC bus voltage Udc+ / Udc-, the switch tube Q1 and the switch tube Q2 are connected in series across the DC bus voltage Udc+ / Udc-, the switch tube Q3 and the switch tube Q4 are connected in series across the DC bus voltage Udc+ / Udc-, the switch tube Q5 and the switch tube Q6 are connected in series across the DC bus voltage Udc+ / Udc-; the sampling resistor Rs1 is connected in series to the output branch at the midpoint of the bridge arm of the switch tube Q1 and the switch tube Q2, the sampling resistor Rs2 is connected in series to the output branch at the midpoint of the bridge arm of the switch tube Q3 and the switch tube Q4, and the sampling resistor Rs3 is connected in series to the output branch at the midpoint of the bridge arm of the switch tube Q1 and the switch tube Q2. The output branches of the midpoints of the bridge arms of the switch tubes Q5 and Q6 are connected; the two ends of the sampling resistors Rs1, Rs2, and Rs3 are respectively connected to the isolated △-Σ modulator 1, the isolated △-Σ modulator 2, and the isolated △-Σ modulator 3; the outputs of the isolated △-Σ modulator 1, the isolated △-Σ modulator 2, and the isolated △-Σ modulator 3 are respectively connected to the LVDS-1 transmitter, the LVDS-2 transmitter, and the LVDS-3 transmitter; the LVDS-1 transmitter, the LVDS-2 transmitter, and the LVDS-3 transmitter are respectively connected to the △-Σ filter module of the main control unit, and at the same time, the enhanced pulse width modulator output of the main control unit is connected to the gate-level isolation drive unit, and the output of the gate-level isolation drive unit controls the switch tubes Q1, Q2, Q3, Q4, Q5, and Q6 respectively.

[0007] Furthermore, the bus voltage acquisition unit is used to collect the externally input DC bus voltage Udc+ / Udc- to generate a bus voltage signal.

[0008] Furthermore, the bus voltage acquisition unit is used to collect the DC bus current flowing through the Udc-path to generate a bus current signal.

[0009] Furthermore, the resolver demodulation unit is used to demodulate the resolver signal to generate an angular position digital signal, and send it to the main control unit via SPI.

[0010] Furthermore, the off-chip AD sampling unit is used to sample the bus voltage signal and bus current signal generated by the bus current acquisition unit and the bus voltage acquisition unit, and send them to the main control unit through SPI.

[0011] Furthermore, the inverter unit is used to convert the externally input DC bus voltage into an AC voltage output with adjustable amplitude and frequency for driving the subsequent load.

[0012] Furthermore, the phase current sampling unit is used to sample the three-phase current signal output by the inverter.

[0013] Furthermore, the current conditioning unit is used to convert the micro voltage signal generated by the phase current sampling unit into a digital signal, and at the same time use an LVDS differential transmitter to convert the digital bit stream signal into a low voltage differential signal for transmission to avoid the influence of common mode noise.

[0014] Furthermore, the main control unit filters and decodes the digital bit stream signal generated by the current conditioning unit through the SDFM module, and converts it to obtain a three-phase current value; based on the three-phase current value, the angular position digital signal generated by the resolver demodulation unit, and the bus voltage signal and bus current signal sent by the off-chip AD sampling unit, the PWM signal is output through the EPWM module through calculation.

[0015] Furthermore, the gate-level isolation driving unit is used to convert the PWM signal output by the main control unit into a control signal of the switch tubes Q1, Q2, Q3, Q4, Q5, and Q6.

[0016] The advantages of the present invention are: the present application provides a servo drive controller based on resistor current isolation sampling, and the three-phase current sampling adopts a precision resistor + isolated △-Σ solution to reduce the hardware size and overhead of the current sampling link. At the same time, the power device adopts a multi-tube parallel solution, which can achieve the expansion of the capacitor capacity in a small volume and the improvement of the inverter efficiency and energy conversion efficiency. In addition, the power device adopts a surface mount packaging form + aluminum substrate design to further improve the heat dissipation efficiency, reduce the size of the radiator, and achieve the design purpose of miniaturization of the servo drive controller. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0018] Figure 1 Schematic diagram of the servo drive controller. DETAILED DESCRIPTION

[0019] In order to make the technical solutions and implementation steps of the embodiments of the present invention more clearly displayed, the technical solutions of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0020] The technical details and illustrative embodiments of the present invention will be described in detail below. In the detailed description below, many specific details are proposed to provide a comprehensive understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention. The present invention is by no means limited to any specific settings and methods proposed below, but covers any improvements, replacements and modifications of structures, methods, devices without departing from the spirit of the present invention. In the accompanying drawings and the following description, known structures and technologies are not shown to avoid unnecessary ambiguity in the present invention.

[0021] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other, and the embodiments can refer to and quote each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0022] like Figure 1 As shown, the present invention provides a servo drive controller based on resistance current isolation sampling, the servo drive controller includes an inverter unit, a phase current sampling unit, a current conditioning unit, a main control unit, a resolver demodulation unit, an off-chip AD sampling unit, a gate-level isolation drive unit, a bus voltage acquisition unit, a bus current acquisition unit, and a bus current acquisition unit, wherein:

[0023] The inverter unit includes switch tube Q1, switch tube Q2, switch tube Q3, switch tube Q4, switch tube Q5, switch tube Q6, and bus support capacitor C1; the phase current sampling unit includes sampling resistors Rs1, Rs2, and Rs3; the current conditioning unit includes LVDS-1 transmitter, LVDS-2 transmitter, LVDS-3 transmitter, isolated △-Σ modulator 1, isolated △-Σ modulator 2, and isolated △-Σ modulator 3; the main control unit includes a △-Σ filter module (SDFM) and an enhanced pulse width modulator (EPWM); the bus voltage acquisition unit includes sampling resistors R2, R3, and an isolated operational amplifier; the bus current acquisition unit includes a sampling resistor Rs4 and an isolated operational amplifier.

[0024] The external input DC bus voltage Udc+ / Udc-, the bus voltage sampling resistors R2 and R3 are connected in series at both ends of the DC bus voltage Udc+ / Udc-, and the voltage u is obtained by voltage division ds , and then sent to the off-chip AD sampling unit through the isolation amplifier; at the same time, the bus current sampling resistor Rs4 is connected in series with the Udc- branch to obtain the bus current i ds The external AD sampling unit is sent through the isolation amplifier; the external AD sampling unit and the resolver demodulation unit are connected to the main control unit through the SPI bus respectively; in addition, the bus support capacitor C1 is connected across the DC bus voltage Udc+ / Udc-, the switch tube Q1 and the switch tube Q2 are connected in series across the DC bus voltage Udc+ / Udc-, the switch tube Q3 and the switch tube Q4 are connected in series across the DC bus voltage Udc+ / Udc-, the switch tube Q5 and the switch tube Q6 are connected in series across the DC bus voltage Udc+ / Udc-; the sampling resistor Rs1 is connected in series to the output branch at the midpoint of the bridge arm of the switch tube Q1 and the switch tube Q2, the sampling resistor Rs2 is connected in series to the output branch at the midpoint of the bridge arm of the switch tube Q3 and the switch tube Q4, and the sampling resistor Rs3 is connected in series to the output branch at the midpoint of the bridge arm of the switch tube Q 5 and the midpoint output branch of the bridge arm of the switch tube Q6; the two ends of the sampling resistors Rs1, Rs2, and Rs3 are respectively connected to the isolated △-Σ modulator 1, the isolated △-Σ modulator 2, and the isolated △-Σ modulator 3; the outputs of the isolated △-Σ modulator 1, the isolated △-Σ modulator 2, and the isolated △-Σ modulator 3 are respectively connected to the LVDS-1 transmitter, the LVDS-2 transmitter, and the LVDS-3 transmitter; the LVDS-1 transmitter, the LVDS-2 transmitter, and the LVDS-3 transmitter are respectively connected to the △-Σ filter module (SDFM) of the main control unit, and the enhanced pulse width modulator (EPWM) output of the main control unit is connected to the gate-level isolation drive unit, and the output of the gate-level isolation drive unit controls the switch tubes Q1, Q2, Q3, Q4, Q5, and Q6 respectively.

[0025] The bus voltage acquisition unit is used to collect the externally input DC bus voltage Udc+ / Udc- to generate a bus voltage signal;

[0026] The bus voltage acquisition unit is used to collect the DC bus current flowing through the Udc-path to generate a bus current signal;

[0027] The resolver demodulation unit is used to demodulate the resolver signal to generate an angular position digital signal, and send it to the main control unit via SPI;

[0028] The off-chip AD sampling unit is used to sample the bus voltage signal and bus current signal generated by the bus current acquisition unit and the bus voltage acquisition unit, and send them to the main control unit through SPI;

[0029] The inverter unit is used to convert the externally input DC bus voltage into an AC voltage output with adjustable amplitude and frequency, so as to drive the subsequent load;

[0030] The phase current sampling unit is used to sample the three-phase current signal output by the inverter;

[0031] The current conditioning unit is used to convert the micro voltage signal generated by the phase current sampling unit into a digital signal, and at the same time use an LVDS differential transmitter to convert the digital bit stream signal into a low voltage differential signal for transmission to avoid the influence of common mode noise;

[0032] The main control unit filters and decodes the digital bit stream signal generated by the current conditioning unit through the SDFM module, and converts it to obtain the three-phase current value; according to the three-phase current value, the angular position digital signal generated by the resolver demodulation unit, the bus voltage signal and the bus current signal sent by the off-chip AD sampling unit, the PWM signal is output through the EPWM module through calculation.

[0033] The gate-level isolation driving unit is used to convert the PWM signal output by the main control unit into the control signal of the switch tubes Q1, Q2, Q3, Q4, Q5 and Q6.

[0034] Specifically, the switch tubes Q1, Q2, Q3, Q4, Q5, and Q6 in the inverter unit form a three-phase bridge inverter topology; the three-phase bridge inverter topology consists of 6 groups of switch tubes, and each group of switch tubes is connected in parallel.

[0035] In practical applications, the switch tube can use the TO-247 package form to dissipate heat through the chassis; it can also use the D2-PAK package form to dissipate heat through the metal substrate.

[0036] In practical applications, the isolated △-Σ modulator adopts a transformer-isolated △-Σ modulator + external independent power supply solution. The external independent power supply is used to provide a 5V power supply voltage for the transformer-isolated △-Σ modulator. An enhanced △-Σ ADC solution with an integrated DC / DC converter can also be selected.

[0037] In practical applications, the transformer-isolated delta-sigma modulator can use chips such as AMC1303M0520. The independent power supply solution can use a push-pull driver connected to an external isolation transformer to generate a 5V power supply voltage. The push-pull driver can use chips such as SN6501. In addition, the independent power supply solution can also use an isolated power supply module to directly generate a 5V power supply voltage.

[0038] In practical applications, the enhanced △-ΣADC solution with integrated DC / DC converter can use an enhanced △-ΣADC chip with internal integrated isolated power supply. This type of chip has its own isolated power supply and does not require external auxiliary power supply.

[0039] Specifically, the isolation forms of the gate-level isolation drive unit include optical fiber isolation, photoelectric isolation, magnetic isolation, and capacitive isolation.

[0040] Specifically, the gate-level isolation driving unit further includes a driving chip for driving the switching tubes Q1, Q2, Q3, Q4, Q5, and Q6 to be turned on or off, and at the same time integrates a desaturation detection function to realize short-circuit protection of the switching tubes.

[0041] Specifically, the main control unit adopts the SDFM module solution provided by the DSP, and may also adopt an FPGA to design a soft core for logic decoding.

[0042] The working principle of a servo drive controller based on resistance current isolation sampling provided by the embodiment of the present invention is as follows:

[0043] The external input DC bus voltage Udc+ / Udc-, the bus voltage sampling resistors R2 and R3 are connected in series at both ends of the DC bus voltage Udc+ / Udc-, and the voltage u is obtained by voltage division ds , and then sent to the off-chip AD sampling unit through the isolation amplifier; at the same time, the bus current sampling resistor Rs4 is connected in series with the Udc- branch to obtain the bus current i dsAfter being isolated from the operational amplifier, it is sent to the off-chip AD sampling unit; the off-chip AD sampling unit and the resolver demodulation unit are respectively connected to the main control unit through the SPI bus; in addition, the bus support capacitor C1 is connected across the DC bus voltage Udc+ / Udc-, the switch tube Q1 and the switch tube Q2 are connected in series across the DC bus voltage Udc+ / Udc-, the switch tube Q3 and the switch tube Q4 are connected in series across the DC bus voltage Udc+ / Udc-, and the switch tube Q5 and the switch tube Q6 are connected in series across the DC bus voltage Udc+ / Udc-; the sampling resistor Rs1 is connected in series to the output branch at the midpoint of the bridge arm of the switch tube Q1 and the switch tube Q2, the sampling resistor Rs2 is connected in series to the output branch at the midpoint of the bridge arm of the switch tube Q3 and the switch tube Q4, and the sampling resistor Rs3 is connected in series to the output branch at the midpoint of the bridge arm of the switch tube Q5 and the switch tube Q6; the sampling resistors Rs1, Rs2, Rs3 are connected in series to the output branch at the midpoint of the bridge arm of the switch tube Q5 and the switch tube Q6; The two ends of s3 are respectively connected to isolated △-Σ modulator 1, isolated △-Σ modulator 2, and isolated △-Σ modulator 3; the outputs of isolated △-Σ modulator 1, isolated △-Σ modulator 2, and isolated △-Σ modulator 3 are respectively connected to LVDS-1 transmitter, LVDS-2 transmitter, and LVDS-3 transmitter; LVDS-1 transmitter, LVDS-2 transmitter, and LVDS-3 transmitter are respectively connected to the △-Σ filter module (SDFM) of the main control unit, and at the same time, the enhanced pulse width modulator (EPWM) output of the main control unit is connected to the gate-level isolation drive unit, and the gate-level isolation drive unit outputs high-frequency square wave signals or selection signals that control the switch tubes Q1, Q2, Q3, Q4, Q5, and Q6 respectively, and converts the external input DC bus voltage Udc+ / Udc- into an AC voltage output with adjustable amplitude and frequency for driving the subsequent load.

[0044] In summary, an embodiment of the present invention provides a servo drive controller based on resistor current isolation sampling. The present invention belongs to the field of electronic engineering technology, and in particular, relates to a servo drive controller based on resistor current isolation sampling. The output end of the gate-level isolation drive amplifier unit is connected to the gate of the inverter switch tube Q, and the two ends of the phase current sampling resistor Rs are connected to the current conditioning unit. By sampling the voltage on the sampling resistor and converting it into a current signal, the phase current is collected. After sampling the phase current, the inverter can be controlled by combining the resolver demodulation results, thereby completing the servo drive function. Through the three-phase current sampling unit, a high-precision, high-power, low-resistance precision sampling resistor can be used to convert the current signal into a voltage signal, and a Hall current sensor solution can be used.

[0045] Embodiment 1

[0046] In this embodiment, the phase current sampling range is -200A to 200A, and a high-power high-precision resistor of 0.2mΩ / 5W is used to convert the current signal into a voltage signal in the range of -50mV to 50mV. By adopting a strong isolated △-Σ modulator, the voltage signal is converted into a digital bit stream signal. The strong isolated △-Σ modulator can adopt a transformer isolated △-Σ modulator + independent power supply solution, or an enhanced △-Σ ADC solution with an integrated DC / DC converter. The independent power supply solution composed of the isolated △-Σ modulator AMC1303M0520 + push-pull circuit used in this embodiment, in which the independent power supply of the push-pull circuit adopts a push-pull power driver + isolation transformer solution. Each phase current sampling uses a set of isolated △-Σ modulator + push-pull independent power supply circuit. The current signal decoding module can use a processor with SDFM function, or can use FPGA design soft core for decoding. This embodiment uses the SDFM module of Ti's TMS320F28377D processor to filter and decode the digital bit stream signal generated by △-ΣADC, and generates a current signal after decoding to participate in closed-loop control. In this embodiment, since the phase current range is -200A to 200A, according to the derating level, the inverter unit needs to use a power switch with a capacity of more than 300A. This type of device mainly appears in the form of power module packaging, which is large in size and heavy in weight, and is not conducive to miniaturization and lightweight design. In this embodiment, three tubes are connected in parallel, and the capacity of a single tube is selected to be 120A. The three tubes in parallel can meet the demand for a capacity of more than 300A, and the on-resistance is reduced to 1 / 3 of that of a single tube, which significantly reduces the heat consumption of the system and improves the inverter conversion efficiency.

[0047] Embodiment 2

[0048] In this embodiment, the phase current sampling range is -50A to 50A, and a high-power high-precision resistor of 0.5mΩ / 5W is used to convert the current signal into a voltage signal in the range of -250mV to 250mV. By adopting a strong isolated △-Σ modulator, the voltage signal is converted into a digital bit stream signal. The strong isolated △-Σ modulator can adopt a transformer isolated △-Σ modulator + independent power supply solution, or an enhanced △-Σ ADC solution with an integrated DC / DC converter. The enhanced △-Σ ADC solution AMC131M01 with an integrated DC / DC converter used in this embodiment only requires a single power supply, and no independent power supply system needs to be designed externally. Each phase current conditioning unit uses a set of AMC131M01 demodulation modules. The current signal decoding module can use a processor with SDFM function, or it can use FPGA to design soft core for decoding. This embodiment uses XILINX's XC7A200T model FPGA, and designs IP soft core to filter and decode the digital bit stream signal generated by △-ΣADC, and generates a current signal after decoding to participate in closed-loop control. In addition, in the three-phase bridge inverter, this embodiment adopts the surface-mounted SiC MOSFET + aluminum substrate solution to improve the thermal conductivity of the system, while significantly reducing the size of the heat sink, and achieving the purpose of miniaturization and lightweight controller.

[0049] A servo drive controller based on resistor current isolation sampling provided in an embodiment of the present invention is a key technology of a humanoid robot joint drive system. By optimizing the three-phase current sampling unit, the current demodulation unit, and the three-phase inverter topology design, the optimized solution selects high-precision, high-power, and low-resistance sampling resistors to collect bus current, and uses a strong isolated △-Σ modulator to convert the voltage signal into a digital bit stream signal, and then uses a decoding unit to implement digital decoding to complete current sampling to achieve the purpose of system closed-loop control. At the same time, the three-phase inverter topology adopts a multi-tube parallel and surface-mount device + aluminum substrate design, which can significantly reduce the volume and weight of the controller, achieve miniaturization, and lightweight design goals to meet the needs of humanoid robot application scenarios.

Claims

1. A servo drive controller based on resistor current isolation sampling, characterized in that: The servo drive controller includes an inverter unit, a phase current sampling unit, a current conditioning unit, a main control unit, a resolver demodulation unit, an off-chip AD sampling unit, a gate-level isolation drive unit, a bus voltage acquisition unit, a bus current acquisition unit, and a bus current acquisition unit, wherein: The inverter unit includes switch tube Q1, switch tube Q2, switch tube Q3, switch tube Q4, switch tube Q5, switch tube Q6, and bus support capacitor C1; the phase current sampling unit includes sampling resistors Rs1, Rs2, and Rs3; the current conditioning unit includes LVDS-1 transmitter, LVDS-2 transmitter, LVDS-3 transmitter, isolated △-Σ modulator 1, isolated △-Σ modulator 2, and isolated △-Σ modulator 3; the main control unit includes a △-Σ filter module and an enhanced pulse width modulator; the bus voltage acquisition unit includes sampling resistors R2, R3, and an isolated operational amplifier; the bus current acquisition unit includes a sampling resistor Rs4 and an isolated operational amplifier; The external input DC bus voltage Udc+ / Udc-, the bus voltage sampling resistors R2 and R3 are connected in series at both ends of the DC bus voltage Udc+ / Udc-, and the voltage u is obtained by voltage division ds , and then sent to the off-chip AD sampling unit through the isolation amplifier; at the same time, the bus current sampling resistor Rs4 is connected in series with the Udc- branch to obtain the bus current i ds The external AD sampling unit is sent through the isolation amplifier; the external AD sampling unit and the resolver demodulation unit are connected to the main control unit through the SPI bus respectively; in addition, the bus support capacitor C1 is connected across the DC bus voltage Udc+ / Udc-, the switch tube Q1 and the switch tube Q2 are connected in series across the DC bus voltage Udc+ / Udc-, the switch tube Q3 and the switch tube Q4 are connected in series across the DC bus voltage Udc+ / Udc-, the switch tube Q5 and the switch tube Q6 are connected in series across the DC bus voltage Udc+ / Udc-; the sampling resistor Rs1 is connected in series to the output branch at the midpoint of the bridge arm of the switch tube Q1 and the switch tube Q2, the sampling resistor Rs2 is connected in series to the output branch at the midpoint of the bridge arm of the switch tube Q3 and the switch tube Q4, and the sampling resistor Rs3 is connected in series to the output branch at the midpoint of the bridge arm of the switch tube Q1 and the switch tube Q2. The output branches of the midpoints of the bridge arms of the switch tubes Q5 and Q6 are connected; the two ends of the sampling resistors Rs1, Rs2, and Rs3 are respectively connected to the isolated △-Σ modulator 1, the isolated △-Σ modulator 2, and the isolated △-Σ modulator 3; the outputs of the isolated △-Σ modulator 1, the isolated △-Σ modulator 2, and the isolated △-Σ modulator 3 are respectively connected to the LVDS-1 transmitter, the LVDS-2 transmitter, and the LVDS-3 transmitter; the LVDS-1 transmitter, the LVDS-2 transmitter, and the LVDS-3 transmitter are respectively connected to the △-Σ filter module of the main control unit, and at the same time, the enhanced pulse width modulator output of the main control unit is connected to the gate-level isolation drive unit, and the output of the gate-level isolation drive unit controls the switch tubes Q1, Q2, Q3, Q4, Q5, and Q6 respectively.

2. A servo drive controller based on resistance current isolation sampling according to claim 1, characterized in that The bus voltage acquisition unit is used to collect the externally input DC bus voltage Udc+ / Udc- to generate a bus voltage signal.

3. A servo drive controller based on resistance current isolation sampling according to claim 1, characterized in that: The bus voltage acquisition unit is used to acquire the DC bus current flowing through the Udc-path to generate a bus current signal.

4. A servo drive controller based on resistance current isolation sampling according to claim 1, characterized in that: The resolver demodulation unit is used to demodulate the resolver signal to generate an angular position digital signal, and send the angular position digital signal to the main control unit via SPI.

5. The servo drive controller based on resistance current isolation sampling according to claim 1, characterized in that: The off-chip AD sampling unit is used to sample the bus voltage signal and bus current signal generated by the bus current acquisition unit and the bus voltage acquisition unit, and send them to the main control unit through SPI.

6. A servo drive controller based on resistance current isolation sampling according to claim 1, characterized in that: The inverter unit is used to convert the externally input DC bus voltage into an AC voltage output with adjustable amplitude and frequency, which is used to drive the subsequent load.

7. The servo drive controller based on resistance current isolation sampling according to claim 1, characterized in that: The phase current sampling unit is used to sample the three-phase current signal output by the inverter.

8. The servo drive controller based on resistance current isolation sampling according to claim 1, characterized in that: The current conditioning unit is used to convert the micro voltage signal generated by the phase current sampling unit into a digital signal, and at the same time uses an LVDS differential transmitter to convert the digital bit stream signal into a low voltage differential signal for transmission to avoid the influence of common mode noise.

9. The servo drive controller based on resistance current isolation sampling according to claim 1, characterized in that: The main control unit filters and decodes the digital bit stream signal generated by the current conditioning unit through the SDFM module, and converts it to obtain the three-phase current value; according to the three-phase current value, the angular position digital signal generated by the resolver demodulation unit, the bus voltage signal and the bus current signal sent by the off-chip AD sampling unit, the PWM signal is output through the EPWM module through calculation.

10. The servo drive controller based on resistance current isolation sampling according to claim 1, characterized in that: The gate-level isolation driving unit is used to convert the PWM signal output by the main control unit into the control signal of the switch tubes Q1, Q2, Q3, Q4, Q5 and Q6.

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