CN117330874A - Power supply detection calibration system and calibration method for EPS steering controller - Google Patents

Abstract

The invention discloses a power supply detection and calibration system and a power supply detection and calibration method for an EPS steering controller. The EOL calibration test equipment comprises a programmable power supply, an industrial personal computer, a communication board card and a test upper computer; the EPS controller is composed of a control circuit, a voltage dividing circuit with small input impedance, an MCU and a communication module. The upper computer gives an instruction to the industrial personal computer through the communication board card, and the industrial personal computer controls the programmable power supply to output a voltage signal. Meanwhile, the EPS controller obtains a high-precision ADC sampling value through a control circuit and a small input impedance voltage dividing circuit and sends the high-precision ADC sampling value to the MCU, the MCU feeds back ADC sampling voltage to the upper computer synchronously through the communication board card, and the upper computer dynamically adjusts a set voltage command to achieve the required set voltage. The power calibration system of the EPS controller of the automobile can improve accuracy of the power calibration system of the EPS controller of the automobile, improve ADC detection accuracy of the controller and reduce quiescent current of the EPS controller.

Description

Power supply detection calibration system and calibration method for EPS steering controller

Technical Field

The invention particularly relates to a power supply detection and calibration system and a power supply detection and calibration method for an EPS steering controller, and belongs to the technical field of vehicle power-assisted steering systems.

Background

The EPS is generally called as Electric Power Steering, namely an electric power steering system, and generally comprises a mechanical steering system, a torque sensor, a vehicle speed sensor, an electronic control unit, a speed reducer, a motor and the like.

The structure schematic diagram of an EPS steering gear control power supply detection calibration system in the prior art is shown in fig. 1, and the system consists of EOL calibration test equipment (1) and an EPS controller (2), wherein the EOL calibration test equipment (1) is used for testing performance function modules of EPS products and calibrating parameters, and comprises a programmable power supply (3), an industrial personal computer (16), a communication board card (11) and a test upper computer (8); the EPS controller is used for determining the rotation direction of the motor and the magnitude of the power assisting current according to signals of the vehicle speed and torque sensors by the ECU, so that the controller capable of providing different power assisting effects for the motor when the vehicle speeds are different is realized. The circuit comprises a large input impedance voltage division circuit (6), an MCU module (7) and a communication module (9). Fig. 2 is a schematic diagram of a voltage dividing circuit of an EPS controller in the prior art. The VBAT voltage is divided by adopting a 1MΩ resistor and a 330KΩ resistor, so that the ADC sampling module requirement of the 0-Vcc input voltage of the MCU (7) is met. Fig. 3 is a flow chart of power calibration of an EPS controller in the prior art. The upper computer is tested to read the set voltage value (8), then the voltage command is controlled and output to the programmable power supply (3) through the communication mode of the communication board card (11) and the industrial personal computer (15), the programmable power supply (3) outputs the set voltage finally, and finally the voltage calibration operation is completed.

However, this method has the following problems:

1. the passenger car supplies power to the EPS system to supply power to the VBAT and supplies power to the storage battery to supply power normally, so in order to prevent the situation that the static current of the EPS controller is too large to cause the feeding condition of the storage battery of the vehicle, the EPS controller is required to have small static current, and a voltage division circuit (6) with large input impedance is required to reduce the static current. However, the voltage dividing circuit (6) with large input impedance causes that the input impedance of the sampling of the MCU (7) ADC is 1M (the MCU is required to be smaller than 50K) so as to cause serious deviation of the sampling error of the MCU ADC, and the actual measurement error is 7-8 times of the absolute sampling error of the MCU standard ADC.

2. The wire harness fixture tool (10) has input impedance, which can lead to a voltage difference of 0.4-0.5V between the power supply A end (4) and the power supply B end (5), so that the power supply voltage input to the EPS controller (B) is not the theoretical power supply voltage of the set voltage, and the voltage calibration method has errors.

3. Meanwhile, related battery voltage test items in the EOL test item process can be misjudged due to pressure difference of a wire harness fixture tool (10), so that the primary qualification rate of an assembly line is reduced, the production capacity is reduced, scrapping is possibly generated, the scrapping rate is improved, and additional production cost is increased.

And 4, the MCU reads the voltage of the power supply B end (5) to perform motor control and diagnosis protection strategy implementation of the EPS, and the MCU voltage error greatly influences the strategy implementation of the whole EPS controller.

5. Because the EPS controller (2) directly supplies normal electricity to the storage battery in the whole passenger vehicle arrangement, the large-impedance voltage dividing circuit (6) adopts large input impedance, but the part of the circuit still has static current, and the whole static current of the EPS controller is increased.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a convenient and practical power supply detection and calibration system and a calibration method for an EPS steering controller.

The invention adopts the following technical scheme for solving the technical problems: an EPS steering gear control power supply detection and calibration system comprises EOL calibration test equipment (1) and an EPS controller (2) which are communicated and interacted.

The EOL calibration test equipment (1) is used for testing performance functional modules and calibrating parameters of EPS products and comprises a programmable power supply (3), an industrial personal computer (16), a communication board card (11) and a test upper computer (8).

The test upper computer (8) is used for testing computer software for testing EPS product functional modules and calibrating parameters, a control instruction is transmitted to the equipment of the industrial personal computer (15) through the communication board card (11), the industrial personal computer (15) controls the programmable power supply to output a direct current power supply with set voltage,

the programmable power supply supplies power to a direct current power supply for normal working of the EPS controller, and a power supply A end (4) on the programmable power supply is connected with a power supply B end (5) of a power supply connector VBAT/GND on the EPS controller (2) through a wire harness fixture tool (10) to provide set voltage required by power supply calibration and test of the EPS controller (2);

the communication board card (11) is used for testing CAN data interaction between the upper computer (8) and the EPS controller (2) through the CAN bus (12), and meanwhile, the communication board card is also used for testing the upper computer (8) to send an execution instruction to the industrial personal computer (15) for testing and calibration execution;

the EPS controller (2) is used for determining the rotation direction of the motor and the power-assisted current according to the vehicle speed and the torque sensor signals by the ECU, so that the controller which can provide corresponding power-assisted effects for the motor under different vehicle speeds is realized. The EPS controller (2) comprises a circuit module, an MCU module (7) and a communication module (9);

the circuit module consists of a control circuit (13) and a small input impedance voltage dividing circuit (14), wherein the controller circuit (13) is used for VBAT voltage sampling control and is used for eliminating the whole vehicle quiescent current of the KL15 IGN switch in a power-down state; the small input impedance voltage dividing circuit (14) is used for meeting the requirement that the sampling voltage of the MCU module (7) meets the 0-Vcc working voltage of ADC sampling, and meanwhile, the ADC sampling input impedance can be enabled to meet the MCU standard input impedance requirement, so that the ADC sampling error caused by high input impedance is reduced from 60LSB to within 8LSB, and the precision of VBAT voltage detection of the EPS controller (2) is met;

the MCU module (7) enables the control circuit (13) to perform sampling opening or sampling closing operation through the control port; and converting the voltage of the VBAT from an analog signal to a digital signal through an ADC sampling port for parameter.

Further, the control circuit (13) comprises a PNP triode Q402, voltage division driving resistors R419 and R420 of the triode Q402, NPN triode Q404 and driving voltage division resistors R429 and R436 of the triode Q404; when the IGN of the EPS system is powered down, the MCU module controls the Q402 to be disconnected, and the static current introduced by the voltage dividing circuit is directly eliminated; when the IGN of the EPS system is electrified, the EPS controller needs to collect the voltage of the storage battery, the MCU controls the Q402 to be opened, and the voltage dividing circuit carries out ADC voltage division sampling;

the small input anti-resistance voltage dividing circuit (14) consists of VBAT voltage dividing resistors R424 and R431 and C417 for ADC sampling, filtering and voltage stabilizing.

Further, the base electrode #1 of the NPN triode Q404 is connected to the voltage dividing points of the voltage dividing resistors R436 and R429 of the control port, the other end of the resistor R429 is directly connected to GND, the resistor R436 is connected to the IO control port of the end of the MCU (7), the emitter #2 of the NPN triode Q404 is connected to GND, the collector #3 of the NPN triode Q404 is connected to the resistor R420, the base #3 of the PNP triode Q402 is connected to the voltage dividing resistors R419 and R420, the emitter #2 of the PNP triode Q402 is connected to the VBAT power supply end, the collector #3 of the PNP triode Q402 is connected to the resistor R424, and the voltage divided by the resistor R424 and the resistor R431 is connected to the ADC sampling port of the MCU (7) to sample the ADC for ADC data sampling of the VBAT voltage.

A calibration method of an EPS steering gear control power supply detection calibration system comprises the following specific steps:

step 1, a test upper computer (8) reads a set voltage value, an output voltage instruction is given to an industrial personal computer (15) through a communication board (11), the output voltage instruction is given to a programmable power supply (3), and the programmable power supply (3) outputs the set voltage of the upper computer; meanwhile, the power A end (4) of the programmable power output end is connected to the power B end (5) of the EPS controller through the wire harness fixture tool (10), so that power supply to the EPS controller (2) is realized;

step 2, the communication board card (11) reads the voltage of the power supply B end (5) of the EPS controller, and judges the power supply voltage of the power supply B end (5) of the EPS controller (2) through the upper computer (8);

and 3, compensating voltage difference caused by the wire harness jig tool (10) after calibrating and calibrating a series of voltages, and storing a final set voltage value by the test upper computer (5) to calibrate an initial set voltage value serving as a reference for the next batch of products.

Furthermore, in the step 1, the wire harness fixture tool (10) is a test probe fixture tool, and is connected with the PCB board end connector part in a probe press-contact mode.

Further, in the step 2, the MCU module (7) sends out the voltage value of the ADC of VBAT through the communication module (9), and the voltage value of VBAT is transmitted to the test upper computer (8) by the communication mode of the CAN bus (12) of the communication board card; the upper computer (8) judges the power supply voltage of the power supply B end (5) of the EPS controller (2), and when the power supply voltage of the power supply B end (5) of the EPS controller (2) is larger than the set voltage VBAT, the upper computer designs the voltage-0.1V; when the power supply voltage at the power supply B end (5) is smaller than the set voltage VBAT, the upper computer sets the voltage +0.1V; when the power voltage at the power supply B end (5) is equal to the set voltage VBAT, the upper computer stores the set voltage.

Further, after the MCU module (7) detects that the controller is electrified through the IGN port, the control port outputs a high level Vcc, namely a high level voltage switch of a Q404#1 pin of the NPN triode Q404#2#3 pin is opened to control conduction, so that the voltage of the Q404#3 pin of the NPN triode Q is GND voltage; the R419 resistor and the R420 resistor divide the voltage VBAT/2 to the pin Q404#1 of the PNP triode, so that the pin #2#3 of the PNP triode Q402 is controlled to be conducted, and the VBAT voltage can be supplied to a small input impedance voltage dividing circuit (14) for ADC voltage sampling;

when the IGN signal is powered down, the MCU control port outputs a low-level GND signal, the Q404#2#3 pin switch is disconnected, and the pin of the triode Q404#2#3 is disconnected to enable the pin of the triode Q404#1 pin control switch to be suspended without voltage input, so that the PNP triode Q404#2#3 pin switch is disconnected and does not work, and the VBAT ADC sampling is closed under the control of the control circuit (13), namely, the EPS controller quiescent current caused by the VBAT voltage sampling is directly eliminated under the state of IGN closing;

the small input impedance voltage dividing circuit (14) divides voltage=vbat 10/61 to an ADC sampling port of the MCU (7) through an R424 resistor and an R431 resistor, and reads the voltage value of the ADC through an ADC module of the MCU (7); the input resistance of the ADC sampling port of the MCU (7) is reduced by the small input impedance voltage dividing circuit (14), so that the absolute error of sampling caused by the input resistance of the ADC can be controlled within +/-8 LSB, and the standard ADC sampling precision requirement is met.

Compared with the prior art, the technical scheme provided by the invention has the following advantages:

1. the input impedance of ADC sampling is reduced by combining the control circuit (13) with the small input impedance voltage dividing circuit (14) so as to meet the requirement of MCU (7) on the input impedance of the ADC, the absolute error of ADC sampling is reduced within a standard range, the battery voltage of the ADC is improved, and the sampling precision of the EPS on the power voltage ADC is improved.

And 2.EPS power supply is constant power supply of the storage battery, and the problem of quiescent current generated by sampling the power supply voltage of the EPS controller in the IGNOFF state can be solved by adding the control circuit (13), so that the quiescent current requirement of a whole vehicle factory is met, and the durable service life of the storage battery is prolonged.

3. Through high accuracy ADC sampling + the EPS controller power calibration flow chart of figure 6, can effectively eliminate the influence of voltage drop that harness tool (10) input impedance led to, make EPS controller power supply B end (5) reach theoretical settlement voltage. (1) The power supply voltage calibration precision of the EPS steering controller is improved; (2) the accuracy of an EPS motor control algorithm and the effectiveness of a diagnosis protection strategy are improved, and erroneous judgment of the protection strategy is eliminated; (3) the false judgment of the occurrence of test items related to the battery voltage in the EOL test process is reduced, the primary qualification rate of the assembly line is improved, and the productivity of the production line is increased. Meanwhile, the rejection rate caused by production is reduced, and the production cost is saved.

Drawings

Fig. 1 is a schematic structural diagram of a control power supply detection calibration system of an EPS steering gear in the prior art.

Fig. 2 is a schematic diagram of a voltage dividing circuit of an EPS controller in the prior art.

Fig. 3 is a flow chart of power calibration of an EPS controller in the prior art.

Fig. 4 is a schematic structural diagram of an EPS steering gear control power supply detection calibration system according to the present invention.

FIG. 5 is a schematic diagram of a control circuit and a voltage divider circuit according to the present invention.

Fig. 6 is a flowchart of the EPS controller power supply voltage calibration according to the invention.

The 1-EOL calibration test device comprises a 1-EOL calibration test device, a 2-EPS controller, a 3-programmable power supply, a 4-power supply A end, a 5-power supply B end, a 6-large input impedance voltage divider circuit, a 7-MCU module, an 8-test upper computer, a 9-communication module, a 10-wire harness fixture, an 11-communication board card, a 12-CAN bus, a 13-control circuit, a 14-small input impedance voltage divider circuit and a 15-industrial personal computer.

Detailed Description

The technical scheme of the invention is further described in detail below with reference to the accompanying drawings:

in order to better understand the solution of the embodiment of the present invention, the following describes the embodiment of the present invention in further detail with reference to the accompanying drawings and the detailed description.

The power supply detection and calibration system for the EPS steering controller provided by the embodiment has the structure shown in fig. 4, and comprises two parts, namely EOL calibration test equipment 1 and an EPS controller 2.

The EOL calibration test equipment is used for testing the performance function module of the EPS product and calibrating parameters and comprises a programmable power supply 3, an industrial personal computer 16, a communication board 11 and a test upper computer 8; the test upper computer is used for testing computer software for testing the function module of the EPS product and calibrating parameters, and transmits control instructions to the industrial personal computer equipment through the communication board card, and the industrial personal computer controls the programmable power supply to output a direct current power supply with set voltage. The programmable power supply supplies power to the direct current power supply for normal working of the EPS controller, and the power supply A end on the programmable power supply is connected with the power supply B end 5 of the power supply connector VBAT/GND on the EPS controller through the wire harness fixture tool 10 to provide set voltage required by power supply calibration and test of the EPS controller. The communication board card is used for testing the CAN data interaction between the upper computer and the EPS controller through the CAN bus 12. Meanwhile, the communication board card is also used for testing the upper computer to send the execution instruction to the industrial personal computer 15 for testing and calibration execution.

The EPS controller is used for determining the rotation direction of the motor and the magnitude of the power assisting current according to signals of the vehicle speed and torque sensors by the ECU, so that the controller capable of providing different power assisting effects when the vehicle speed is different is realized.

The EPS controller comprises a circuit module, an MCU module 7 and a communication module 9. The circuit module consists of a control circuit 13 and a small input impedance voltage dividing circuit 14, wherein the control circuit is used for VBAT voltage sampling control so as to eliminate the whole vehicle quiescent current of the KL15 IGN switch in the power-down state; the small input impedance voltage dividing circuit is used for meeting the requirement that the MCU module sampling voltage meets the 0-Vcc working voltage of ADC sampling, simultaneously can greatly reduce the ADC sampling input impedance, reduces the ADC sampling error caused by high input impedance from 60LSB to within 8LSB, and meets the precision of VBAT voltage detection of the EPS controller.

The control circuit mainly comprises a triode Q402, voltage division driving resistors R419 and R420 of the triode Q402, and driving voltage division resistors R429 and R436 of the triodes Q404 and Q404. The small input impedance voltage dividing circuit consists of VBAT voltage dividing resistors R424 and R431 and C417 for ADC sampling filtering voltage stabilization. The base electrode #1 of the NPN triode Q404 is connected with the voltage dividing points of the voltage dividing resistors R436 and R429 of the control port, the other end of the R429 resistor is directly connected with GND, and the R436 resistor is connected with the IO control port of the MCU module end. The emitter #2 of the NPN triode Q404 is connected with GND, the collector #3 of the NPN triode Q404 is connected with an R420 resistor, the base #3 of the PNP triode Q402 is connected with a VBAT voltage dividing resistor R419 and an R420 voltage dividing point, the emitter #2 of the PNP triode Q402 is connected with a VBAT power supply end, the collector #3 of the PNP triode Q402 is connected with an R424 resistor, and the divided voltage of the R424 resistor and the R431 resistor is connected with an ADC sampling port of the MCU module to sample ADC data of the VBAT divided voltage.

The control circuit controls the power supply of VBAT to be turned on and off, when IGN is ignited and electrified, the MCU controls the NPN Q404 triode to be conducted, thereby controlling the PNP Q402 triode to be conducted so that the VBAT voltage normally enters the sampling channel; when IGN ignition is powered down, the NPN Q404 triode is closed, so that the PNP Q402 triode is controlled to be closed, and VBAT voltage is disconnected and enters an ADC sampling channel, so that quiescent current caused by VBAT voltage sampling when IGN ignition is turned down is finally eliminated, and the standby time of the whole vehicle storage battery is prolonged.

The specific working mode of the control circuit is as follows: when the MCU module detects that the KL15 IGN is in a state of igniting and powering on, the MCU module outputs high-level Vcc through a control port pulling-up control port, so that the base electrode #1 port of the NPN triode Q404 is divided by resistors R436 and R429 and then high-level voltage Vcc/2 applied to a pin of the NPN triode Q404 #1 is pulled up to open the collector electrode #3 to be conducted with the transmitter #2, and therefore, the R419 and R420 are divided by VBAT/2 to enable a control circuit (13) of the transmitter #2 collector electrode #3 of the PNP triode Q402 to be conducted to enable ADC sampling of VBAT voltage to be opened; when the MCU module (7) detects that the KL15 IGN is in a power-on state, the MCU module (7) is used for pulling the control port high through the control port to output a low level GND, so that the NPN triode Q404 is closed, the base #1 of the PNP triode Q402 controls the current to cause the triode to be closed, and the ADC sampling is closed; the small input impedance voltage dividing circuit (14) divides the voltage VBAT by R424 and R431 resistors to the ADC sampling port of the MCU (7), and reads the voltage value through the ADC module. The voltage of VBAT is converted from an analog signal to a digital signal through an ADC sampling port for parameters.

The small input impedance voltage divider circuit is used for reducing the input resistance of the ADC sampling port of the MCU module, can control the sampling absolute error caused by the ADC input resistance within +/-8 LSB, meets the standard ADC sampling precision requirement, and reduces the VBAT sampling error.

The MCU module is mainly used for calculating and logically processing ADC sampling; controlling the control circuit to work according to the IGN signal; and transmitting the VBAT ADC sampling voltage to the test upper computer through the communication module for voltage calibration.

The communication module is used for transmitting information such as VBAT ADC sampling voltage of the MCU module to a CAN bus communication mode of the test upper computer.

The calibration method of the EPS steering controller power supply detection calibration system of the embodiment, as shown in fig. 6, includes the following steps:

the upper computer is tested to read the set voltage value, the output voltage instruction is given to the industrial personal computer through the communication board, the output voltage instruction is given to the programmable power supply, and the programmable power supply outputs the set voltage of the upper computer. Meanwhile, the power A end of the programmable power output end is connected to the power B end of the EPS controller through the wire harness fixture tool, so that power supply to the EPS controller is realized. The wire harness fixture is a test probe type fixture and is connected with the PCB end connector part in a probe press-contact mode.

As shown in fig. 5, after the EPS controller detects that the controller is powered on through the IGN port, the MCU outputs a high level Vcc through the control port, that is, the high level voltage=vcc×r436/(r436+r429) =vcc×10/(10+10) =vcc/2 is given to the pin q404#1 of the NPN transistor after the voltage is divided by the R436 10K resistor and the R429 10K resistor, so that the pin q404#2#3 of the NPN transistor is controlled to be turned on, and the voltage of the pin q404#3 of the NPN transistor is GND. The pin #2#3 of the PNP transistor Q402 is controlled to be turned on by the resistor R419 10K, the resistor R420 10K voltage division=vbat×r419/(r419+r420) =vbat×10/(10+10) =vbat/2 to the pin Q404#1, so that the VBAT voltage can be supplied to the small input impedance voltage divider circuit for ADC voltage sampling.

When the IGN signal is powered down, the MCU module control port outputs a low-level GND signal, namely the pin Q404#1 of the NPN triode is low, so that the pin Q404#2#3 of the NPN triode is disconnected. Since the NPN triode Q404#2#3 pin is disconnected to enable the PNP triode Q404#1 pin control switch pin to be suspended without voltage input, the PNP triode Q404#2#3 pin is disconnected and does not work, and therefore, the control circuit is controlled to be closed, namely, under the state that IGN is closed, the static current of the EPS controller caused by VBAT voltage sampling is directly eliminated.

The small input impedance voltage dividing circuit divides voltage=vbat×r431/(r431+424) =vbat×10/(10+51) =vbat×10/61 through R424K resistor and R431 10K resistor to an ADC sampling port of the MCU (7), and reads the voltage value of the ADC through an ADC module of the MCU module. The input resistance of the ADC sampling port of the MCU module is reduced through the small input impedance voltage dividing circuit, so that the sampling absolute error caused by the input resistance of the ADC is controlled within 8LSB, and the standard ADC sampling precision requirement is met.

The MCU module sends the voltage value of the ADC of the VBAT through the communication module, and the CAN bus of the communication board card) transmits the voltage value of the VBAT to the test upper computer in a communication mode. The test upper computer judges through the calibration method shown in fig. 6, and when the test upper computer judges that the power supply voltage of the power supply B end of the EPS controller is larger than the set voltage VBAT, the design voltage of the upper computer is-0.1V. When the test upper computer judges that the power supply voltage at the power supply B end is smaller than the set voltage VBAT, the upper computer sets the voltage +0.1V. When the test upper computer judges that the power voltage of the power supply B end is equal to the set voltage VBAT, the upper computer stores the set voltage.

After compensation is performed through a series of voltage calibration, voltage difference caused by the wire harness fixture tool can be compensated, the final set voltage value is stored in the test upper computer, and the initial set voltage value serving as a reference is calibrated for the next batch of products.

The foregoing has shown and described the basic principles, principal features and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the specific embodiments described above, and that the above specific embodiments and descriptions are provided for further illustration of the principles of the present invention, and that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. The scope of the invention is defined by the claims and their equivalents.

Claims (7)

1. An EPS steering gear control power detects calibration system, its characterized in that: the EOL calibration test device comprises EOL calibration test equipment (1) and an EPS controller (2) which are communicated and interacted;

the EOL calibration test equipment (1) is used for testing the performance function module of the EPS product and calibrating parameters and comprises a programmable power supply (3), an industrial personal computer (16), a communication board card (11) and a test upper computer (8);

the test upper computer (8) is used for testing computer software for testing EPS product functional modules and calibrating parameters, a control instruction is transmitted to the equipment of the industrial personal computer (15) through the communication board card (11), the industrial personal computer (15) controls the programmable power supply to output a direct current power supply with set voltage,

the programmable power supply supplies power to a direct current power supply for normal working of the EPS controller, and a power supply A end (4) on the programmable power supply is connected with a power supply B end (5) of a power supply connector VBAT/GND on the EPS controller (2) through a wire harness fixture tool (10) to provide set voltage required by power supply calibration and test of the EPS controller (2);

the communication board card (11) is used for testing CAN data interaction between the upper computer (8) and the EPS controller (2) through the CAN bus (12), and meanwhile, the communication board card is also used for testing the upper computer (8) to send an execution instruction to the industrial personal computer (15) for testing and calibration execution;

the EPS controller (2) is used for determining the rotation direction of the motor and the power-assisted current according to the vehicle speed and the torque sensor signals by the ECU, so that the controller which can provide corresponding power-assisted effects for the motor under different vehicle speeds is realized. The EPS controller (2) comprises a circuit module, an MCU module (7) and a communication module (9);

the circuit module consists of a control circuit (13) and a small input impedance voltage dividing circuit (14), wherein the controller circuit (13) is used for VBAT voltage sampling control and is used for eliminating the whole vehicle quiescent current of the KL15 IGN switch in a power-down state; the small input impedance voltage dividing circuit (14) is used for meeting the requirement that the sampling voltage of the MCU module (7) meets the 0-Vcc working voltage of ADC sampling, and meanwhile, the ADC sampling input impedance can be enabled to meet the MCU standard input impedance requirement, so that the ADC sampling error caused by high input impedance is reduced from 60LSB to within 8LSB, and the precision of VBAT voltage detection of the EPS controller (2) is met;

the MCU module (7) enables the control circuit (13) to perform sampling opening or sampling closing operation through the control port; and converting the voltage of the VBAT from an analog signal to a digital signal through an ADC sampling port for parameter.

2. The EPS steering gear control power detection and calibration system of claim 1, wherein:

the control circuit (13) comprises a PNP triode Q402, voltage division driving resistors R419 and R420 of the triode Q402, a NPN triode Q404 and driving voltage division resistors R429 and R436 of the Q404 triode; when the IGN of the EPS system is powered down, the MCU module controls the Q402 to be disconnected, and the static current introduced by the voltage dividing circuit is directly eliminated; when the IGN of the EPS system is electrified, the EPS controller needs to collect the voltage of the storage battery, the MCU controls the Q402 to be opened, and the voltage dividing circuit carries out ADC voltage division sampling;

the small input anti-resistance voltage dividing circuit (14) consists of VBAT voltage dividing resistors R424 and R431 and C417 for ADC sampling, filtering and voltage stabilizing.

3. The EPS steering gear control power detection and calibration system of claim 1, wherein: the base electrode #1 of the NPN triode Q404 is connected with voltage dividing resistors R436 and R429 of a control port, the other end of the resistor R429 is directly connected with GND, the resistor R436 is connected with an IO control port of an MCU (7) end, the emitter #2 of the NPN triode Q404 is connected with GND, the collector #3 of the NPN triode Q404 is connected with the resistor R420, the base #3 of the PNP triode Q402 is connected with voltage dividing resistors R419 and R420 of a VBAT voltage, the emitter #2 of the PNP triode Q402 is connected with a VBAT power supply end, the collector #3 of the PNP triode Q402 is connected with the resistor R424, and the voltage divided by the resistor R424 and the resistor R431 is connected with an ADC sampling port of the MCU (7) to sample ADC data of the voltage divided by VBAT.

4. A method for calibrating an EPS steering gear control power supply detection calibration system according to claim 1, characterized by: the method comprises the following specific steps:

step 1, a test upper computer (8) reads a set voltage value, an output voltage instruction is given to an industrial personal computer (15) through a communication board (11), the output voltage instruction is given to a programmable power supply (3), and the programmable power supply (3) outputs the set voltage of the upper computer; meanwhile, the power A end (4) of the programmable power output end is connected to the power B end (5) of the EPS controller through the wire harness fixture tool (10), so that power supply to the EPS controller (2) is realized;

step 2, the communication board card (11) reads the voltage of the power supply B end (5) of the EPS controller, and judges the power supply voltage of the power supply B end (5) of the EPS controller (2) through the upper computer (8);

and 3, compensating voltage difference caused by the wire harness jig tool (10) after calibrating and calibrating a series of voltages, and storing a final set voltage value by the test upper computer (5) to calibrate an initial set voltage value serving as a reference for the next batch of products.

5. The calibration method of the EPS steering gear control power detection calibration system according to claim 4, characterized by: in the step 1, the wire harness fixture tool (10) is a test probe type fixture tool and is connected with the PCB end connector part in a probe press-contact mode.

6. The calibration method of the EPS steering gear control power detection calibration system according to claim 4, characterized by: in the step 2, the MCU module (7) sends out the voltage value of the ADC of the VBAT through the communication module (9), and the voltage value of the VBAT is transmitted to the test upper computer (8) in a communication mode of the CAN bus (12) of the communication board card; the upper computer (8) judges the power supply voltage of the power supply B end (5) of the EPS controller (2), and when the power supply voltage of the power supply B end (5) of the EPS controller (2) is larger than the set voltage VBAT, the upper computer designs the voltage-0.1V; when the power supply voltage at the power supply B end (5) is smaller than the set voltage VBAT, the upper computer sets the voltage +0.1V; when the power voltage at the power supply B end (5) is equal to the set voltage VBAT, the upper computer stores the set voltage.

7. The calibration method of the EPS steering gear control power detection calibration system of claim 6, wherein: after the MCU module (7) detects that the controller is electrified through the IGN port, the control port outputs a high level Vcc, namely a high level voltage switch of a pin Q404#1 of the NPN triode opens a pin Q404#2#3 to control conduction, so that the voltage of the pin Q404#3 of the NPN triode is GND voltage; the R419 resistor and the R420 resistor divide the voltage VBAT/2 to the pin Q404#1 of the PNP triode, so that the pin #2#3 of the PNP triode Q402 is controlled to be conducted, and the VBAT voltage can be supplied to a small input impedance voltage dividing circuit (14) for ADC voltage sampling;

when the IGN signal is powered down, the MCU control port outputs a low-level GND signal, the Q404#2#3 pin switch is disconnected, and the pin of the triode Q404#2#3 is disconnected to enable the pin of the triode Q404#1 pin control switch to be suspended without voltage input, so that the PNP triode Q404#2#3 pin switch is disconnected and does not work, and the VBAT ADC sampling is closed under the control of the control circuit (13), namely, the EPS controller quiescent current caused by the VBAT voltage sampling is directly eliminated under the state of IGN closing;

the small input impedance voltage dividing circuit (14) divides voltage=vbat 10/61 to an ADC sampling port of the MCU (7) through an R424 resistor and an R431 resistor, and reads the voltage value of the ADC through an ADC module of the MCU (7); the input resistance of the ADC sampling port of the MCU (7) is reduced by the small input impedance voltage dividing circuit (14), so that the absolute error of sampling caused by the input resistance of the ADC can be controlled within +/-8 LSB, and the standard ADC sampling precision requirement is met.