Power-assisted motor control method and system, computer equipment and medium

Abstract

The invention provides a power-assisted motor control method and system, computer equipment and a medium, and the method comprises the steps: recording a non-fault three-phase sampling resistor as a standard resistor when at least one fault resistor exists in a three-phase sampling resistor disposed in a steer-by-wire system; the estimated current value corresponding to the fault resistor is calculated through the standard current value corresponding to the standard resistor; and finally, according to the estimated current value and the standard current value, the external power-assisted motor is controlled to assist power, so that when the fault resistor exists in the steer-by-wire system, the external power-assisted motor can be controlled to assist power in steering to a certain extent by simulating the current corresponding to the fault resistor. The problem that in the prior art, when a sampling resistor arranged in a steer-by-wire system breaks down, the steer-by-wire system loses power-assisted steering, and consequently the driving risk is increased is solved, and the driving safety of a vehicle is improved.

Description

Technical Field

[0001] The present invention relates to the field of motor control, and in particular, to a control method, system, computer device, and medium for a power-assisted motor. Background Art

[0002] A steer-by-wire system is a vehicle steering control system that realizes steering operations through electronic signals and an electric power-assisted device. In the existing steer-by-wire system, the power-assisted steering motor is an actuator of the steer-by-wire system, directly responding to the steering performance of the steer-by-wire system and the safety of the driver.

[0003] In the existing steer-by-wire system, when a sampling resistor set in the steer-by-wire system has a fault such as a short circuit or an open circuit, it will cause the sampling circuit of the whole vehicle to break down. At this time, the steer-by-wire system can only prevent further circuit failures of the vehicle by directly reporting the sampling circuit fault and cutting off the assistance at the same time. This processing method will cause the entire steer-by-wire system to lose steering assistance. Therefore, when a fault occurs and the driver needs to park the vehicle in a safe place, the driver can only control the steering of the vehicle normally by applying a large manual torque forcefully, resulting in inconvenience for the driver to perform self-rescue when the vehicle breaks down and increasing the driving risk. Summary of the Invention

[0004] Based on this, in view of the above problems, it is necessary to propose a control method, system, computer device, and medium for a power-assisted motor that can still achieve motor assistance when a sampling circuit in a steer-by-wire system fails, thereby reducing the driving risk.

[0005] The present invention provides a control method for a power-assisted motor used to control the power-assisted motor in an SBW system, including:

[0006] S1, determining whether there is a faulty resistor among the three-phase sampling resistors set in the SBW;

[0007] S2, if so, recording the non-faulty three-phase sampling resistors as standard resistors, and obtaining the standard current value flowing through the standard resistors;

[0008] S3, calculating the estimated current value corresponding to the faulty resistor according to the standard current value, where the estimated current value is the estimated value of the current when the current flows through the faulty resistor;

[0009] S4, controlling an external power-assisted motor to provide assistance according to the estimated current value and the standard current value.

[0010] Further, the step S2 specifically includes:

[0011] S2a, when only one of the three-phase sampling resistors set in the SBW has a fault, mark the non-faulty three-phase sampling resistors as standard resistors;

[0012] S2b, obtain the current duty cycle of the standard resistor within a preset set time period;

[0013] S2c, obtain the standard current value flowing through the standard resistor according to the current duty cycle.

[0014] Further, the step S2c specifically includes:

[0015] S2d, when the current duty cycle of the standard resistor within the preset set time period does not exceed the set duty cycle threshold, then obtain the standard current value of the standard resistor and return to execute step S3.

[0016] Further, the step S3 specifically includes:

[0017] S3a, after matching the corresponding current calculation formula from the preset calculation formula library according to the standard current value, input the standard current value into the current calculation formula for calculation, so as to output the estimated current value.

[0018] Further, the three-phase sampling resistors include an A-phase sampling resistor, a B-phase sampling resistor, and a C-phase sampling resistor;

[0019] Then the step S3a specifically includes:

[0020] S3b, if the A-phase sampling resistor is the faulty resistor, the B-phase sampling resistor and the C-phase sampling resistor are the standard resistors;

[0021] Then obtain the B-phase current value corresponding to the B-phase sampling resistor and the C-phase current value corresponding to the C-phase sampling resistor;

[0022] S3c, match the first current calculation formula from the calculation formula library according to the B-phase current value and the C-phase current value and perform calculation. At this time, the first current calculation formula is specifically:

[0023] I a2 =﹣I b1 -I c1

[0024] wherein, the I b1 is the B-phase current value, and the I c1 is the C-phase current value;

[0025] S3d, update the value of the I a2 output by the first current calculation formula to the A-phase current estimated value.

[0026] Further, the three-phase sampling resistors include an A-phase sampling resistor, a B-phase sampling resistor, and a C-phase sampling resistor;

[0027] Then the step S3a specifically includes:

[0028] S3e. If the B-phase sampling resistor is the faulty resistor and the A-phase sampling resistor and the C-phase sampling resistor are the standard resistors;

[0029] Then obtain the A-phase current value corresponding to the A-phase sampling resistor and the C-phase current value;

[0030] S3f. Match and calculate a second current calculation formula from the calculation formula library according to the A-phase current value and the C-phase current value. The second current calculation formula is specifically expressed as:

[0031] I b2 = -I a1 -I c1

[0032] wherein, the I a1 is the A-phase current value, and the I c1 is the C-phase current value;

[0033] S3g. Update the output value of the second current calculation formula to the estimated value of the B-phase current. b2

[0034] Further, the three-phase sampling resistors include an A-phase sampling resistor, a B-phase sampling resistor, and a C-phase sampling resistor;

[0035] Then the step S3a specifically includes:

[0036] S3h. If the C-phase sampling resistor is the faulty resistor and the A-phase sampling resistor and the B-phase sampling resistor are the standard resistors;

[0037] Then obtain the A-phase current value and the B-phase current value, and match and calculate a third current calculation formula from the calculation formula library according to the A-phase current value and the B-phase current value. At this time, the third current calculation formula is specifically expressed as:

[0038] I c2 = -I a1 -I b1

[0039] wherein, the I a1 is the A-phase current value, and the I b1 is the B-phase current value;

[0040] ​S3i, output the third current calculation formula to output the I c2 Update the value to the estimated value of the C-phase current.

[0041] The present invention also provides an assist motor control system for controlling an assist motor in an SBW system, characterized by comprising:

[0042] A fault resistance judgment unit for judging whether there is at least one fault resistance in the three-phase sampling resistors provided in the SBW;

[0043] A current marking unit for marking the non-faulty three-phase sampling resistors as standard resistors and obtaining the standard current value flowing through the standard resistors;

[0044] A current estimation unit for estimating the current value corresponding to the fault resistance according to the standard current value, where the estimated current value is the estimated value of the current when the current flows through the fault resistance;

[0045] A motor drive unit for controlling an external assist motor to provide assistance according to the estimated current value and the standard current value.

[0046] A computer device includes a memory and a processor. When the computer program stored in the memory is executed by the processor, the processor performs the following steps:

[0047] S1, judge whether there is a fault resistance in the three-phase sampling resistors provided in the SBW;

[0048] S2, if so, mark the non-faulty three-phase sampling resistors as standard resistors and obtain the standard current value flowing through the standard resistors;

[0049] S3, estimate the current value corresponding to the fault resistance according to the standard current value, where the estimated current value is the estimated value of the current when the current flows through the fault resistance;

[0050] S4, control an external assist motor to provide assistance according to the estimated current value and the standard current value.

[0051] A computer-readable medium stores a computer program. When the computer program is executed by a processor, the processor performs the following steps:

[0052] S1, judge whether there is a fault resistance in the three-phase sampling resistors provided in the SBW;

[0053] S2, if so, mark the non-faulty three-phase sampling resistors as standard resistors and obtain the standard current value flowing through the standard resistors;

[0054] S3. Estimate the estimated current value corresponding to the faulty resistor based on the standard current value, where the estimated current value is the estimated value of the current when the current flows through the faulty resistor;

[0055] S4. Control the external assist motor to provide assistance based on the estimated current value and the standard current value.

[0056] The above assist motor control method, system, computer device, and medium determine that when there is at least one faulty resistor among the three-phase sampling resistors set in the steer-by-wire system, the non-faulty three-phase sampling resistors are recorded as standard resistors, estimate the estimated current value corresponding to the faulty resistor through the standard current value corresponding to the standard resistor, and finally control the external assist motor to provide assistance based on the estimated current value and the standard current value. This realizes that when there is a faulty resistor in the steer-by-wire system, the external assist motor can be controlled to provide a certain degree of steering assistance by simulating the current corresponding to the faulty resistor, solving the problem in the prior art that when the sampling resistor in the steer-by-wire system fails, the steer-by-wire system loses steering assistance, making it inconvenient for the driver to self-rescue during a failure and increasing the driving risk, and improving the driving safety of the vehicle. Description of the Drawings

[0057] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0058] Figure 1 It is a flowchart of the assist motor control method in one embodiment;

[0059] Figure 2 It is a flowchart of the assist motor control method in another embodiment;

[0060] Figure 3 It is a flowchart of the assist motor control method in another embodiment;

[0061] Figure 4 It is a flowchart of the assist motor control method in another embodiment;

[0062] Figure 5 It is a schematic structural diagram of the assist motor control system in one embodiment;

[0063] Figure 6 It is a structural block diagram of a computer device in one embodiment. Detailed Embodiments

[0064] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0065] Reference Figure 1 , the present invention provides a control method for a booster motor, which is used to control the booster motor in the SBW system, including:

[0066] S1. Determine whether there is a faulty resistor among the three-phase sampling resistors set in the SBW.

[0067] As described in step S1 above, the background system determines whether there is a faulty resistor among the three-phase sampling resistors set in the SBW (i.e., the chassis-by-wire steering system). It can be understood that the function of setting the three-phase sampling resistors in the SBW is to sample the three-phase current inside the SBW. Therefore, the three-phase sampling resistors are at least realized by combining three sampling resistors. And in this embodiment, the background system can also be a pre-driver chip set in the circuit. Therefore, in this embodiment, it is actually the pre-driver chip that determines whether there is a sampling resistor among the above three sampling resistors that has a fault such as short circuit or open circuit, and records it as the faulty resistor.

[0068] S2. If so, record the non-faulty three-phase sampling resistors as standard resistors, and obtain the standard current value flowing through the standard resistors.

[0069] As described in the above embodiment, the pre-driver chip records the sampling resistor with a fault among the three-phase sampling resistors as the faulty resistor, and records the sampling resistor without a fault as the standard resistor. Then, the pre-driver chip samples the current flowing through the standard resistor, thereby generating the standard current value.

[0070] S3. Calculate the estimated current value corresponding to the faulty resistor according to the standard current value, where the estimated current value is the estimated value of the current when the current flows through the faulty resistor.

[0071] As described in step S3 above, the pre-driver chip calculates the estimated current value according to the obtained standard current value corresponding to the standard resistor. It can be understood that the estimated current value is the current value estimated by the pre-driver chip for the current flowing through the faulty resistor, that is, the estimated current value.

[0072] S4. Control the external booster motor to provide assistance according to the estimated current value and the standard current value.

[0073] As described in step S4 above, the pre-drive chip controls the external assist motor to provide assistance according to the estimated current value and the standard current value. It can be understood that the control signal obtained by the external assist motor should be controlled by the three-phase supply current output by the original SBW. Therefore, when there is a faulty resistor among the three-phase sampling resistors corresponding to the three-phase supply current, the three-phase supply current cannot be sampled and output normally. At this time, after the pre-drive chip calculates the estimated current value corresponding to the faulty resistor, it can re-integrate the estimated current value and the standard current value into the three-phase supply current and output it to the external assist motor, so as to achieve the effect of controlling the external assist motor to provide assistance;

[0074] It can be understood that since the estimated current value is an analog signal at this time and cannot achieve true current output, the external assist motor is actually powered by only two-phase supply current at this time. Therefore, although the external assist motor cannot perform the normal torque assistance function at this time, it can still provide a certain amount of torque assistance, so as to facilitate the driver to park the faulty vehicle in a safe place;

[0075] In addition, since there are still two normally operating standard resistors in the three-phase sampling resistor when there is a single faulty resistor in the three-phase sampling resistor, the pre-drive chip can control the external assist motor to provide assistance by simulating the output of a single faulty resistor and using the two-phase supply current output by the two standard resistors. When there are two faulty resistors in the three-phase sampling resistor, only one normally operating standard resistor in the three-phase sampling resistor outputs a single-phase supply current. At this time, although the pre-drive chip can still control the external assist motor to provide assistance by simulating the output of the two faulty resistors, the standard resistor will have an increased failure rate due to excessive load at this time, and the single-phase supply current is not enough to support the normal output of the external assist motor. Therefore, in the technical solution of the present invention, there can be only one faulty resistor in the three-phase sampling resistor.

[0076] In this embodiment, through the above method, when it is determined that there is at least one faulty resistor in the three-phase sampling resistors set in the steer-by-wire system, the non-faulty three-phase sampling resistors are recorded as standard resistors, and the estimated current value corresponding to the faulty resistor is calculated through the standard current value corresponding to the standard resistor. Finally, according to the estimated current value and the standard current value, the external assist motor is controlled to provide assistance, realizing that when there is a faulty resistor in the steer-by-wire system, the external assist motor can be controlled to provide a certain degree of steering assistance by simulating the current corresponding to the faulty resistor. This solves the problem in the prior art that when the sampling resistor set in the steer-by-wire system fails, the steer-by-wire system will lose steering assistance, making it inconvenient for the driver to self-rescue in case of a failure and increasing the driving risk, thus improving the driving safety of the vehicle.

[0077] In one embodiment, step S2 specifically includes:

[0078] S2a. When there is only one faulty resistor in the three-phase sampling resistors set in the SBW, the non-faulty three-phase sampling resistors are recorded as standard resistors;

[0079] S2b. Obtain the current duty cycle of the standard resistor within a preset set time period;

[0080] S2c. Obtain the standard current value flowing through the standard resistor according to the current duty cycle.

[0081] As described in the above embodiment, when the pre-driver chip determines that there is one faulty resistor in the three-phase sampling resistors set in the SBW, the non-faulty three-phase sampling resistors are recorded as standard resistors. After that, the pre-driver chip obtains the current duty cycle of the standard resistor within a preset set time period. It can be understood that in this embodiment, since when the current duty cycle corresponding to the standard resistor sampled by the pre-driver chip is too large, the pre-driver chip may not be able to sample the current of the standard resistor due to a large sampling current error. Therefore, the pre-driver chip needs to obtain the standard current value flowing through the standard resistor according to the specific situation of the current duty cycle.

[0082] In one embodiment, step S2c specifically includes:

[0083] S2d. When the current duty cycle of the standard resistor within a preset set time period does not exceed the set duty cycle threshold, obtain the standard current value of the standard resistor and then return to execute step S3.

[0084] As described in the above embodiments, the duty cycle threshold is 85%. Therefore, when the pre-driver chip determines that the current duty cycle of the standard current is less than 85% within a set period, the current flowing through the standard resistor can be sampled to generate the standard current value. At this time, after the pre-driver chip obtains the standard current value of the standard resistor, it returns to execute step S3

[0085] In one embodiment, step S3 specifically includes:

[0086] S3a. After matching the corresponding current calculation formula from the preset calculation formula library according to the standard current value, input the standard current value into the current calculation formula for calculation, so as to output the estimated current value.

[0087] In one embodiment, step S3 specifically includes:

[0088] S3a. After matching the corresponding current calculation formula from the preset calculation formula library according to the standard current value, input the standard current value into the current calculation formula for calculation, so as to output the estimated current value.

[0089] As described in the above embodiments, the pre-driver chip obtains the preset calculation formula library. It can be understood that several current calculation formulas are stored in the calculation formula library. It can be understood that different standard current values can obtain different current calculation formulas from the calculation formula library. For example, when the standard current value is the B-phase current value and the C-phase current value, the pre-driver chip can match and obtain the first current calculation formula from the calculation formula library according to the B-phase current value and the C-phase current value. Similarly, when the standard current value is the A-phase current value and the C-phase current value, the pre-driver chip can match and obtain the second current calculation formula from the calculation formula library according to the A-phase current value and the C-phase current value. Similarly, when the standard current value is the A-phase current value and the B-phase current value, the pre-driver chip can match and obtain the third current calculation formula from the calculation formula library according to the A-phase current value and the B-phase current value, and input the standard current value into the above current calculation formula for calculation, so as to output the estimated current value.

[0090] In one embodiment, the three-phase sampling resistors include an A-phase sampling resistor, a B-phase sampling resistor, and a C-phase sampling resistor;

[0091] Then refer to Figure 2 , step S3a specifically includes:

[0092] S3b, if the sampling resistor of phase A is the faulty resistor, and the sampling resistors of phase B and phase C are the standard resistors;

[0093] then obtain the phase B current value corresponding to the sampling resistor of phase B and the phase C current value corresponding to the sampling resistor of phase C;

[0094] S3c, match the first current calculation formula from the calculation formula library according to the phase B current value and the phase C current value and perform the calculation. At this time, the first current calculation formula is specifically expressed as:

[0095] I a2 = -I b1 -I c1

[0096] wherein, the I b1 is the phase B current value, and the I c1 is the phase C current value;

[0097] S3d, output the value of I a2 in the first current calculation formula and update it to the estimated value of the phase A current.

[0098] As described in the above embodiment, since the three-phase sampling resistors need to sample the three-phase power supply currents in the SBW, the three-phase sampling resistors are at least composed of three sampling resistors, namely the sampling resistor of phase A, the sampling resistor of phase B, and the sampling resistor of phase C. When the pre-driver chip determines that the sampling resistor of phase A is the faulty resistor, the sampling resistors of phase B and phase C are the standard resistors, and within the set time period, neither the duty cycle of the phase B current corresponding to the sampling resistor of phase B nor the duty cycle of the phase C current corresponding to the sampling resistor of phase C exceeds the duty cycle threshold, obtain the phase B current value corresponding to the sampling resistor of phase B and the phase C current value corresponding to the sampling resistor of phase C. It can be understood that since the duty cycle threshold is 85%, when neither the duty cycle of the phase B current nor the duty cycle of the phase C current exceeds 85% within the set time period, the pre-driver chip further obtains the phase B current value corresponding to the sampling resistor of phase B and the phase C current value corresponding to the sampling resistor of phase C, and matches the first current calculation formula from the calculation formula library according to the phase B current value and the phase C current value and performs the calculation. The first current calculation formula is specifically expressed as:

[0099] I a2 = -I b1 -I c1

[0100] It can be understood that in the first current calculation formula, the I b1 is the phase B current value, and the Ic1 is the C-phase current value. At this time, the I calculated by the pre-driver chip through the first current calculation formula a2 is the estimated A-phase current value;

[0101] It can be understood that according to Kirchhoff's current law ia + ib + ic = 0, the corresponding remaining phase current value can be calculated from the determined two-phase current values. Therefore, the I calculated by the first current calculation formula a2 is the current output value obtained when the A-phase sampling resistor is not faulty;

[0102] In addition, it can be understood that at this time, the B-phase current value and the C-phase current value are the two-phase power supply currents for actually controlling the external assist motor, and the A-phase current estimated value is only an analog current without actual current output.

[0103] Reference Figure 3 , in one embodiment, the three-phase sampling resistors include an A-phase sampling resistor, a B-phase sampling resistor, and a C-phase sampling resistor;

[0104] Then the step S3a specifically includes:

[0105] S3e, if the B-phase sampling resistor is the faulty resistor, and the A-phase sampling resistor and the C-phase sampling resistor are the standard resistors;

[0106] Then obtain the A-phase current value and the C-phase current value corresponding to the A-phase sampling resistor;

[0107] S3f, match the second current calculation formula from the calculation formula library according to the A-phase current value and the C-phase current value and perform the calculation. The second current calculation formula is specifically expressed as:

[0108] I b2 = -I a1 -I c1

[0109] wherein, the I a1 is the A-phase current value, and the I c1 is the C-phase current value;

[0110] S3g, update the value of the I output by the second current calculation formula b2 to the estimated B-phase current value.

[0111] As described in the above embodiments, when the pre-driver chip determines that the B-phase sampling resistor is the faulty resistor, the A-phase sampling resistor and the C-phase sampling resistor are the standard resistors, and within a set time period, neither the duty cycle of the A-phase current corresponding to the A-phase sampling resistor nor the duty cycle of the C-phase current corresponding to the C-phase sampling resistor exceeds the duty cycle threshold, the A-phase current value corresponding to the A-phase sampling resistor and the C-phase current value are obtained. It can be understood that since the duty cycle threshold is 85%, when neither the A-phase current duty cycle nor the C-phase current duty cycle exceeds 85% within the set time period, the pre-driver chip further obtains the A-phase current value corresponding to the A-phase sampling resistor and the C-phase current value corresponding to the C-phase sampling resistor, and matches and calculates a second current calculation formula from the calculation formula library according to the A-phase current value and the C-phase current value. The second current calculation formula is specifically expressed as:

[0112] I b2 =﹣I a1 -I c1

[0113] It can be understood that in the second current calculation formula, the I a1 is the A-phase current value, the I c1 is the C-phase current value. At this time, the I b2 calculated by the pre-driver chip through the second current calculation formula is the estimated value of the A-phase current;

[0114] It can be understood that according to Kirchhoff's current law ia + ib + ic = 0, the corresponding current value of the remaining one phase can be calculated from the two determined phase current values. Therefore, the I b2 calculated by the second current calculation formula is the current output value obtained when the B-phase sampling resistor is not faulty;

[0115] In addition, it can be understood that at this time, the A-phase current value and the C-phase current value are the two-phase power supply currents used to actually control the external assist motor, and the B-phase current estimated value is only an analog current without actual current output.

[0116] Reference Figure 4 , in one embodiment, the three-phase sampling resistors include an A-phase sampling resistor, a B-phase sampling resistor, and a C-phase sampling resistor;

[0117] Then the step S3a specifically includes:

[0118] S3h, if the C-phase sampling resistor is the faulty resistor, the A-phase sampling resistor and the B-phase sampling resistor are the standard resistors;

[0119] Then, the A-phase current value and the B-phase current value are obtained, and a third current calculation formula is matched from the calculation formula library according to the A-phase current value and the B-phase current value for calculation. At this time, the third current calculation formula is specifically embodied as:

[0120] I c2 = -I a1 -I b1

[0121] wherein, the I a1 is the A-phase current value, and the I b1 is the B-phase current value;

[0122] S3i, output the third current calculation formula, and update the value of the I c2 to the estimated value of the C-phase current.

[0123] As described in the above embodiment, when the pre-driver chip determines that the C-phase sampling resistor is the faulty resistor, the A-phase sampling resistor and the B-phase sampling resistor are the standard resistors, and within the set time period, neither the A-phase current duty ratio nor the B-phase current duty ratio exceeds the duty ratio threshold, the A-phase current value and the B-phase current value are obtained. It can be understood that since the duty ratio threshold is 85%, when neither the A-phase current duty ratio nor the B-phase current duty ratio exceeds 85% within the set time period, the pre-driver chip obtains the A-phase current value and the B-phase current value again, and matches and calculates a third current calculation formula from the calculation formula library according to the A-phase current value and the B-phase current value. The third current calculation formula is specifically embodied as:

[0124] I c2 = -I a1 -I b1

[0125] It can be understood that in the third current calculation formula, the I a1 is the A-phase current value, and the I b1 is the B-phase current value. Then, the I c2 calculated by the pre-driver chip through the third current calculation formula is the estimated value of the C-phase current;

[0126] It can be understood that according to Kirchhoff's current law ia + ib + ic = 0, the corresponding remaining phase current value can be calculated through the two determined phase current values. Therefore, the I c2 calculated by the third current calculation formula is the current output value obtained when the C-phase sampling resistor is not faulty.

[0127] In addition, it can be understood that at this time, the A-phase current value and the B-phase current value are the two-phase power supply currents used to actually control the external power-assisted motor, and the C-phase current estimation value is only a simulated current without actual current output.

[0128] refer to Figure 5 The present invention also provides a power-assisting motor control system for controlling the power-assisting motor in the SBW system, including:

[0129] A fault resistance determination unit 10 is used to determine whether there is at least one fault resistance in the three-phase sampling resistors set in the SBW;

[0130] The current marking unit 20 is used to mark the three-phase sampling resistor that is not faulty as a standard resistor and obtain a standard current value flowing through the standard resistor;

[0131] A current estimation unit 30, configured to calculate an estimated current value corresponding to the fault resistor according to the standard current value, wherein the estimated current value is an estimated value of the current when the current flows through the fault resistor;

[0132] The motor driving unit 40 is used to control the external power-assisting motor to provide power assistance according to the estimated current value and the standard current value.

[0133] The above-mentioned units are used to execute the above-mentioned power-assisted motor control system, and will not be introduced one by one here.

[0134] Figure 6 FIG. 1 shows an internal structure diagram of a computer device in an embodiment. The computer device may be a server, including but not limited to a high-performance computer and a high-performance computer cluster. Figure 6 As shown, the computer device includes a processor, a memory and a network interface connected via a system bus. Among them, the memory includes a non-volatile storage medium and an internal memory. The non-volatile storage medium of the computer device stores an operating system and may also store a computer program, which, when executed by the processor, enables the processor to implement the power-assisted motor control method. The internal memory may also store a computer program, which, when executed by the processor, enables the processor to execute the power-assisted motor control method.

[0135] In one embodiment, the power assist motor control method provided by the present invention can be implemented in the form of a computer program. The computer program can be Figure 6 The computer device shown in the figure is run. The memory of the computer device can store various program templates constituting the power assist motor control system. For example: 10 - fault resistance judgment unit, 20 - current marking unit, 30 - current estimation unit, 40 - motor drive unit.

[0136] A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the following steps are implemented:

[0137] S1, determine whether there is a faulty resistor among the three-phase sampling resistors set in the SBW;

[0138] S2, if so, record the non-faulty three-phase sampling resistors as standard resistors, and obtain the standard current value flowing through the standard resistors;

[0139] S3, calculate the estimated current value corresponding to the faulty resistor according to the standard current value, where the estimated current value is the estimated value of the current when the current flows through the faulty resistor;

[0140] S4, control an external assist motor to provide assistance according to the estimated current value and the standard current value.

[0141] From the above embodiments, it can be seen that the greatest beneficial effect of the present invention is that when it is determined that there is at least one faulty resistor among the three-phase sampling resistors set in the steer-by-wire system, the non-faulty three-phase sampling resistors are recorded as standard resistors, and the estimated current value corresponding to the faulty resistor is calculated through the standard current value corresponding to the standard resistor. Finally, by controlling the external assist motor to provide assistance according to the estimated current value and the standard current value, when there is a faulty resistor in the steer-by-wire system, the external assist motor can be controlled to provide a certain degree of steering assistance by simulating the current corresponding to the faulty resistor, solving the problem that the steer-by-wire system loses steering assistance when the sampling resistor set in the steer-by-wire system fails, resulting in the driver being unable to perform self-rescue easily when a failure occurs and increasing the driving risk, and improving the driving safety of the vehicle.

[0142] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention.

Claims

1. A method for controlling an assist motor, which is used to control the assist motor in an SBW system, characterized in that, include: S1, determine whether there is a fault resistor in the three-phase sampling resistor set in SBW; S2: If yes, record the three-phase sampling resistor that is not faulty as a standard resistor, and obtain a standard current value flowing through the standard resistor; S3, calculating an estimated current value corresponding to the fault resistor according to the standard current value, wherein the estimated current value is an estimated value of the current when the current flows through the fault resistor; S4, controlling the external power-assisting motor to assist according to the estimated current value and the standard current value.

2. The assist motor control method according to claim 1, wherein The step S2 specifically includes: S2a, when there is only one faulty resistor among the three-phase sampling resistors set in the SBW, the three-phase sampling resistor that is not faulty is recorded as a standard resistor; S2b, obtaining the current duty cycle of the standard resistor within a preset setting period; S2c, obtaining a standard current value flowing through the standard resistor according to the current duty cycle.

3. The assist motor control method according to claim 2, wherein, The step S2c specifically includes: S2d, when the current duty cycle of the standard resistor within the preset setting time period does not exceed the set duty cycle threshold, the standard current value of the standard resistor is obtained and then the process returns to step S3.

4. The assist motor control method according to claim 1, wherein The step S3 specifically includes: S3a, after matching a corresponding current estimation formula from a preset estimation formula library according to the standard current value, input the standard current value into the current estimation formula for estimation, thereby outputting the estimated current value.

5. The assist motor control method according to claim 4, wherein The three-phase sampling resistor includes an A-phase sampling resistor, a B-phase sampling resistor and a C-phase sampling resistor; Then the step S3a specifically includes: S3b, if the A-phase sampling resistor is the fault resistor, the B-phase sampling resistor and the C-phase sampling resistor are the standard resistors; Then obtain the B-phase current value corresponding to the B-phase sampling resistor and the C-phase current value corresponding to the C-phase sampling resistor; S3c, matching a first current estimation formula from the estimation formula library according to the B-phase current value and the C-phase current value and performing estimation, wherein the first current estimation formula is specifically embodied as follows: I a2 = -I b1 -I c1 wherein, the I b1 is the B-phase current value, and the I c1 is the C-phase current value; S3d, update the output I value of the first current calculation formula to the estimated value of the phase A current. a2 ​ 6. The assist motor control method according to claim 4, wherein, The three-phase sampling resistor includes an A-phase sampling resistor, a B-phase sampling resistor and a C-phase sampling resistor; Then the step S3a specifically includes: S3e, if the B-phase sampling resistor is the fault resistor, the A-phase sampling resistor and the C-phase sampling resistor are the standard resistors; Then obtain the A-phase current value and the C-phase current value corresponding to the A-phase sampling resistor; S3f, matching a second current estimation formula from the estimation formula library and performing estimation according to the A-phase current value and the C-phase current value, wherein the second current estimation formula is specifically embodied as: I b2 = -I a1 -I c1 Among them, the I a1 is the value of the phase A current, and the I c1 is the value of the phase C current; S3g, update the output value of the second current calculation formula to the estimated value of the B-phase current. b2 ​ 7. The assist motor control method according to claim 4, characterized in that, The three-phase sampling resistor includes an A-phase sampling resistor, a B-phase sampling resistor and a C-phase sampling resistor; Then the step S3a specifically includes: S3h, if the C-phase sampling resistor is the fault resistor, the A-phase sampling resistor and the B-phase sampling resistor are the standard resistors; Then obtain the A-phase current value and the B-phase current value, and match and calculate the third current calculation formula from the calculation formula library according to the A-phase current value and the B-phase current value. At this time, the third current calculation formula is specifically embodied as: I c2 = -I a1 -I b1 Among them, the I a1 is the current value of phase A, and the I b1 is the current value of phase B; S3i, output the third current calculation formula and update the value of I c2 to the estimated value of the C-phase current.

8. A power assist motor control system for controlling a power assist motor in an SBW system, characterized in that, including: A fault resistance judgment unit, configured to judge whether there is at least one faulty resistance in the three-phase sampling resistors provided in the SBW; A current marking unit, configured to mark the non-faulty three-phase sampling resistors as standard resistors, and obtain the standard current values flowing through the standard resistors; A current estimation unit, configured to estimate the estimated current value corresponding to the faulty resistance according to the standard current value, where the estimated current value is the estimated value of the current when the current flows through the faulty resistance; A motor drive unit, configured to control an external assist motor to provide assistance according to the estimated current value and the standard current value.

9. A computer device, characterized in that, It includes a memory, a processor, and a computer program stored in the memory and executable on the processor. It is characterized in that when the processor executes the computer program, the assist motor control method according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, the assist motor control method according to any one of claims 1 to 7 is implemented.

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