Phase shut-off device self-test control method

Abstract

A phase shut-off device self-test control method (200). The method (200) is applicable to a dual-redundant electric power steering system (100) in a vehicle. The dual-redundant electric power steering system (100) comprises a first motor winding (130) and a second motor winding (140). The phase shut-off device self-test control method (200) comprises: a coordinated control step (210): performing coordinated control on a first motor winding (130) and a second motor winding (140), such that the total output torque of the first motor winding (130) and the second motor winding (140) is 0; and a phase shut-off device self-test step (220): controlling phase shut-off devices (PD1, PD2) of each phase of the first motor winding (130) and the second motor winding (140) so as to execute the self-test of the phase shut-off devices (PD1, PD2) on the basis of current values of each phase.

Description

Related breaker self-test control method

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 202410110599.8, filed on January 25, 2024, entitled “Related Circuit Breaker Self-Test Control Method,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to the field of vehicle control, and more particularly to a related breaker self-checking control method. Background Art

[0004] Currently, dual-redundant electric power steering systems are commonly used in vehicles to achieve axial torque assistance for the vehicle driver via electric motors. For example, patent document CN 109843701A provides a dual-redundant electric power steering system. This dual-redundant electric power steering system uses two control units to independently control two sets of motor windings to generate power assist torque. These two control units each include a microcontroller unit (MCU), a drive circuit, an inverter bridge, and related circuit breakers (also known as phase switches or phase relays) connecting the motors and controllers. The two sets of motor windings are two sets of three-phase armature windings of a permanent magnet synchronous motor, and their structures are generally identical. Furthermore, metal-oxide-semiconductor field-effect transistors (MOSFETs) are generally used as switching devices in steering systems. Each phase of each three-phase motor winding is connected to the control unit via a MOSFET.

[0005] Summary of the Invention

[0006] The embodiments of the present disclosure provide a self-test control method for a related circuit breaker, which eliminates the undesired torque and motor rotation caused by applying a traditional self-test method for a switching device to the self-test of a related circuit breaker in an electric power steering device.

[0007] The related circuit breaker self-test control method provided by an embodiment of the present disclosure is applicable to a dual-redundant electric power steering system in a vehicle. The dual-redundant electric power steering system includes a first motor winding and a second motor winding. The related circuit breaker self-test control method includes: a collaborative control step of collaboratively controlling the first motor winding and the second motor winding so that the total output torque of the first motor winding and the second motor winding is 0; and a related circuit breaker self-test step of controlling the related circuit breakers of each phase of the first motor winding and the second motor winding to perform related circuit breaker self-test according to the current value of each phase. In one embodiment, the collaborative control step of the related circuit breaker self-test control method of the present disclosure includes: collaboratively setting the duty cycle of the first motor winding and the second motor winding so that the total output torque of the first motor winding and the second motor winding is 0.

[0008] In one embodiment, the related circuit breaker self-test step of the related circuit breaker self-test control method disclosed in the present invention includes: simultaneously disconnecting / closing the related circuit breakers of each phase of the first motor winding and the second motor winding; collecting the current values ​​of each phase of the first motor winding and the second motor winding; when performing the shutdown self-test, for the first motor winding and the second motor winding, determining whether the largest one of the current values ​​of each phase is less than the current threshold; if the largest one is less than the current threshold, the shutdown is successful, otherwise the shutdown is faulty; when performing the pull-in self-test, performing a pull-in self-test on each of the three phases of the first motor winding and the second motor winding in turn, and the phase currently being self-tested is the current target phase, determining whether the current value of the current target phase of the first motor winding and the second motor winding is greater than the current threshold; if the current value of the current target phase is greater than the current threshold, the current target phase is successfully pulled in, otherwise the current target phase is pulled in faulty.

[0009] In one embodiment, when performing a shutdown self-test, the coordinated control steps of the circuit breaker self-test control method disclosed herein include: driving the first motor winding and the second motor winding according to a first pair of three-phase duty cycles for a first time period, wherein the first pair of three-phase duty cycles ensures that the sum of the duty cycle of each phase of the first motor winding and the duty cycle of a corresponding phase of the second motor winding is 1; and driving the first motor winding and the second motor winding according to a second pair of three-phase duty cycles for a second time period, wherein the second pair of three-phase duty cycles is different from the first pair of three-phase duty cycles but still ensures that the sum of the duty cycle of each phase of the first motor winding and the duty cycle of a corresponding phase of the second motor winding is 1; and the circuit breaker self-test steps include: collecting a first set of phase current values ​​of the first motor winding and the second motor winding during the first time period; collecting a second set of phase current values ​​of the first motor winding and the second motor winding during the second time period; and determining, for each of the first motor winding and the second motor winding, a maximum value between the first set of phase current values ​​and the second set of phase current values ​​as the maximum of the phase current values.

[0010] In one embodiment, during the pull-in self-check, the cooperative control steps of the relevant breaker self-check control method of the present disclosure include: cooperatively setting the duty cycles of the first motor winding and the second motor winding, such that the duty cycle of the current target phase of the first motor winding is x, the duty cycles of the other two phases of the first motor winding are both 1 - x, and the duty cycle of the current target phase of the second motor winding is 1 - x, the duty cycles of the other two phases of the second motor winding are both x, where 0.5 < x ≤ 0.6; and driving the first motor winding and the second motor winding according to the set duty cycles within a predetermined time period; the relevant breaker self-check steps include: during the predetermined time period, respectively collecting the current values of the current target phases of the first motor winding and the second motor winding.

[0011] According to the relevant breaker self-check control method of the embodiment of the present disclosure, the cooperative control steps make the total output torque of the first motor winding and the second motor winding of the dual-redundancy electric power steering system be 0. In the case where the total output torque of the first motor winding and the second motor winding is 0, the relevant breaker self-check steps are executed to self-check the relevant breakers of each phase of the first motor winding and the second motor winding according to the current values of each phase, thereby avoiding unexpected torque and motor rotation during the relevant breaker self-check process; by cooperatively setting the duty cycles of the first motor winding and the second motor winding, the sum of the duty cycle of each phase of the first motor winding and the corresponding phase of the second motor winding is always 1, and the two sets of motor windings generate currents with the same magnitude and opposite directions, and then generate torques with opposite directions to cancel each other out, so that the total output torque of the first motor winding and the second motor winding is 0; in addition, when self-checking each set of relevant breakers, two sets of duty cycles are alternately given, so that the current directions of two phases of the three-phase windings are changed successively, preventing omissions in the disconnection self-check of the relevant breakers. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present invention can be better understood from the following description of the specific embodiments in conjunction with the accompanying drawings, where:

[0013] FIG. 1 shows a schematic block diagram of a dual-redundancy electric power steering system according to an embodiment of the present disclosure.

[0014] FIG. 2 shows a schematic flowchart of a relevant breaker self-check control method according to an embodiment of the present disclosure.

[0015] FIG. 3 shows a flowchart of the disconnection self-check process of a relevant breaker according to an embodiment of the present disclosure.

[0016] FIG. 4 shows a flowchart of the pull-in self-check process of a relevant breaker according to an embodiment of the present disclosure.

[0017] FIG5 shows a schematic block diagram of an electronic device used in a vehicle according to an embodiment of the present invention. DETAILED DESCRIPTION

[0018] The features and exemplary embodiments of various aspects 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 will be apparent 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 merely intended 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 configuration and algorithm proposed below, but covers any modification, replacement, and improvement of elements, components, and algorithms without departing from the spirit of the present invention. In the accompanying drawings and the following description, known structures and techniques are not shown to avoid causing unnecessary ambiguity to the present invention.

[0019] In addition, it should be noted that the term "A is connected to B" used herein may mean "A is directly connected to B" or "A is indirectly connected to B via one or more other elements". In this document, independent of any other instance or use of "at least one" or "one or more", the terms "one" or "an" are used to include one or more than one. In this document, the term "or" is used to refer to a non-exclusive or, so that "A or B" includes "A but not B", "B but not A", and "A and B", unless otherwise indicated. Moreover, in the appended claims, the terms "first", "second", and "third", etc., are used merely as labels and are not intended to imply a numerical order to their objects.

[0020] Dual-redundant electric power steering systems are often used in vehicles to enable motors to provide axial torque assistance to the driver. In a dual-redundant system including dual-redundant electric power steering systems, if one control unit experiences an abnormality, a corresponding circuit breaker disconnects that control unit from the corresponding motor winding, isolating it from the electrical system. The remaining functioning control unit then continues to drive the corresponding motor winding to generate assist torque. Therefore, in such a dual-redundant system, the circuit breaker is a crucial safety device, requiring it to accurately and promptly respond to disconnection and closing commands issued by the control unit. During the circuit breaker self-test, it is necessary to determine whether the circuit breaker is properly switching on and off.

[0021] If a traditional switching device self-test method is used to self-test the relevant circuit breakers in a dual-redundant electric power steering system, the specific process would include, for example, applying a certain voltage to the relevant circuit breaker and then issuing an opening command to detect whether current is generated. If current is generated, the relevant circuit breaker is short-circuited and cannot be opened. Alternatively, an opening command is issued to detect whether current is generated. If current is not generated, the relevant circuit breaker is short-circuited and cannot be closed. When the relevant circuit breaker is self-tested using this process, current is generated when the relevant circuit breaker is closed during the self-test. Because the relevant circuit breaker is connected to the motor, current flows through the motor windings, generating torque and causing the motor to rotate. For power steering systems, there is no torque request during the relevant circuit breaker self-test, and the motor should not generate any torque and should remain stationary. This unexpected torque and motor rotation do not meet design and safety requirements and may also cause unintended steering wheel rotation.

[0022] To eliminate the undesirable torque and motor rotation caused by applying traditional switching device self-test methods to the self-test of the related circuit breakers in electric power steering systems, the traditional approach is to reduce the voltage applied during the self-test until the generated torque cannot overcome the friction of the motor itself, thereby achieving motor standstill. However, this also results in a very small current, resulting in little difference in the current between the open and closed states of the related circuit breaker, making it difficult to distinguish the conduction state of the related circuit breaker from the current. In other words, while the motor is stationary, the purpose of the self-test function itself is sacrificed.

[0023] Embodiments of the present application provide a method for self-testing a related circuit breaker, which is applicable to a dual-redundant system or a dual-electronic control system that needs to keep the motor from outputting torque during the self-test of the related circuit breaker, for example, a dual-redundant electric power steering system, and in particular, a dual-redundant electric power steering system that uses a six-phase permanent magnet synchronous motor or two three-phase permanent magnet synchronous motors.

[0024] For the sake of convenience, this application will take a dual-redundant electric power steering system as an example to describe the proposed related breaker self-test control method, by way of illustration and not limitation.

[0025] FIG1 is a schematic block diagram of a dual-redundant electric power steering system 100 according to an embodiment of the present disclosure. It should be noted that FIG1 only illustrates the components and signal flows within the dual-redundant electric power steering system that are relevant to the technical solution of the present application. Other components and signal flows function as commonly used in the art and are not further described here.

[0026] As shown in FIG1 , the dual-redundant electric power steering system 100 includes two substantially identical control units, namely a first control unit 110 and a second control unit 120, each configured to independently control a first motor winding 130 and a second motor winding 140. The first motor winding 130 and the second motor winding 140 may be, for example, two windings of a six-phase permanent magnet synchronous motor (PMSM) or two windings of a three-phase PMSM.

[0027] As shown in Figure 1, the first control unit 110 may include a first MCU (MCU1), a first gate driver (GDU1), a first bridge arm module (B61), a first related breaker (PD1), a first phase current sampler (S1) and a first related breaker driver chip (PDD1); correspondingly, the second control unit 120 may include a second MCU (MCU2), a second gate driver (GDU2), a second bridge arm module (B62), a second related breaker (PD2), a second phase current sampler (S2) and a second related breaker driver chip (PDD2).

[0028] The U, V, and W phases of the first motor winding 130 are represented by U1, V1, and W1, respectively. The U, V, and W phases of the second motor winding 140 are represented by U2, V2, and W2, respectively.

[0029] The first bridge arm module B61 and the second bridge arm module B62 each include a U phase, a V phase, and a W phase. Each phase is composed of two switching elements, an upper bridge and a lower bridge, whose duty cycles are complementary. The switching elements used in the embodiments of the present application can include, for example, MOSFETs, contactors such as mechanical switches, or insulated-gate bipolar transistors (IGBTs).

[0030] The first related circuit breaker PD1 and the second related circuit breaker PD2 each include three switching elements (eg, MOSFET, contactor, or IGBT, etc.), denoted as PDu1, PDv1, PDw1 and PDu2, PDv2, PDw2, respectively.

[0031] The first MCU MCU1 sends a control instruction to the first gate driver GDU1, so that the first gate driver GDU1 drives the first bridge arm module B61 to control the U phase, V phase and W phase (ie, U1, V1, W1) of the first motor winding 130 by controlling the start end of the first related breaker PD1.

[0032] The second MCU MCU2 sends a control instruction to the second gate driver GDU2, so that the second gate driver GDU2 drives the second bridge arm module B62 to control the U phase, V phase and W phase (i.e., U2, V2, W2) of the second motor winding 230 by controlling the start end of the second related breaker PD2.

[0033] The first phase current sampler S1 is used to collect the first set of phase current values ​​PCu1, PCv1, PCw1 processed by the first gate driver GDU1. The second phase current sampler S2 is used to collect the second set of phase current values ​​PCu2, PCv2, PCw2 processed by the second gate driver GDU2.

[0034] The relevant circuit breaker self-test includes the shutdown self-test phase and the pull-in self-test phase. Generally speaking, the shutdown self-test is performed first, followed by the pull-in self-test. For example, in the dual-redundant electric power steering system shown in Figure 1, before performing the relevant circuit breaker self-test, it is necessary to ensure that all other components are functioning normally.

[0035] The following describes the method for self-testing related circuit breakers of the present application by taking the dual-redundant electric power steering system shown in FIG. 1 as an example.

[0036] 2 is a schematic flow chart of a circuit breaker self-checking control method 200 according to an embodiment of the present disclosure. The circuit breaker self-checking control method 200 may be applicable to the dual-redundant electric power steering system 100 shown in FIG1 .

[0037] The related breaker self-test control method 200 includes a coordinated control step in block 210 , in which the first motor winding and the second motor winding are coordinated to control the first motor winding and the second motor winding so that the total output torque of the first motor winding and the second motor winding is 0. For example, in FIG1 , the first motor winding 130 and the second motor winding 140 are coordinated to control the total output torque of the first motor winding and the second motor winding to be 0.

[0038] As described with reference to FIG1 , in a dual-redundant electric power steering system, a first control unit and a second control unit independently control the first motor winding and the second motor winding, respectively. In one implementation, a general control unit may be configured to control the first control unit and the second control unit to achieve coordinated control of the first motor winding and the second motor winding. In another implementation, one of the first control unit and the second control unit may be used as a master control unit, while the other may be used as a slave control unit to achieve coordinated control of the first motor winding and the second motor winding. In yet another implementation, the first control unit and the second control unit may be collaboratively programmed so that the control of the first motor winding by the first control unit and the control of the second motor winding by the second control unit can be coordinated.

[0039] In some embodiments, cooperatively controlling the first motor winding and the second motor winding includes cooperatively setting the duty cycles of the first motor winding and the second motor winding so that the total output torque of the first motor winding and the second motor winding is 0. For example, the sum of the duty cycles of each phase of the first motor winding and the duty cycle of a corresponding phase of the second motor winding is set to 1, so that the torques generated by the first motor winding and the second motor winding are equal in magnitude and opposite in direction, and the torques cancel each other out, so that the total output torque of the motor is 0.

[0040] The circuit breaker self-test control method 200 includes a circuit breaker self-test step in block 220, wherein the circuit breakers of each phase of the first motor winding and the second motor winding are controlled to perform circuit breaker self-tests based on the current values ​​of each phase. For example, in FIG1 , when the total output torque of the first motor winding 130 and the second motor winding 140 is zero, the first circuit breaker PD1 and the second circuit breaker PD2 are controlled to perform self-tests based on the first set of phase current values ​​PCu1, PCv1, and PCw1 collected by the first phase current sampler S1 and the second set of phase current values ​​PCu2, PCv2, and PCw2 collected by the second phase current sampler S2.

[0041] It should be noted that when performing self-tests on relevant circuit breakers, generally speaking, the shutdown self-test is performed first, and then the pull-in self-test is performed. However, according to actual needs, the pull-in self-test can also be performed first, and then the shutdown self-test.

[0042] The disclosed self-test control method for related circuit breakers considers each group of three-phase circuit breakers as a whole, effectively simplifying self-test steps and saving self-test time. For example, during a shutdown self-test, disconnect commands are issued simultaneously to two groups of three-phase circuit breakers, totaling six circuit breakers, rather than disconnecting each phase one at a time. This method utilizes the characteristics of a dual-redundant system and motors to apply voltages to both groups of circuit breakers in a specific manner during self-tests. This ensures that the torques generated on the three-phase windings of the two motors are equal in magnitude and opposite in direction, thereby canceling each other out and reducing the total output torque of the motors to zero.

[0043] The following will introduce the shutdown self-test process and the pull-in self-test process of the relevant circuit breaker in detail with reference to FIG3 and FIG4.

[0044] FIG3 shows a flow chart of a shutdown self-test process 300 of a related circuit breaker according to an embodiment of the present disclosure.

[0045] When performing shutdown self-test, for the first motor winding and the second motor winding, determine whether the largest one of the phase current values ​​is less than the current threshold. If the largest one is less than the current threshold, the shutdown is successful, otherwise the shutdown fails.

[0046] The turn-off self-check process 300 starts at block 310. At block 310, the first phase disconnection driver chip PDD1 and the second phase disconnection driver chip PDD2 respectively send disconnection instructions to the first phase disconnector PD1 and the second phase disconnector PD2.

[0047] The turn-off self-check process 300 includes, at block 320, the first MCU MCU1 sending the first three-phase duty ratio instructions DTu1, DTv1, DTw1 to the first gate driver GDU1, while the second MCU MCU2 sends the second three-phase duty ratio instructions DTu2, DTv2, DTw2 to the second gate driver GDU2. Among them, the first three-phase duty ratio instructions DTu1, DTv1, DTw1 specify the duty ratios of the U-phase, V-phase, and W-phase of the first motor winding, and the second three-phase duty ratio instructions DTu2, DTv2, DTw2 specify the duty ratios of the U-phase, V-phase, and W-phase of the second motor winding. And the sum of the duty ratios of each phase specified in the first three-phase duty ratio instructions DTu1, DTv1, DTw1 and the corresponding phase specified in the second three-phase duty ratio instructions DTu2, DTv2, DTw2 is 1.

[0048] As pointed out above, the duty ratios of the upper bridge and the lower bridge included in each phase of the first bridge arm module B61 and the second bridge arm module B62 are complementary. Therefore, it is only necessary to send a duty ratio instruction to one of the bridges (e.g., the upper bridge or the lower bridge).

[0049] To ensure that the total output torque of the vehicle's motor is 0, it is necessary to ensure that the sum of the duty ratios of each phase specified in the first three-phase duty ratio instructions DTu1, DTv1, DTw1 sent by the first MCU MCU1 and the corresponding phase specified in the second three-phase duty ratio instructions DTu2, DTv2, DTw2 sent by the second MCU MCU2 is 1. For example, assume that the duty ratios of DTu1, DTv1, DTw1 are set to x, 1 - x, 1 - x respectively. Then the duty ratios of DTu2, DTv2, DTw2 should be set to 1 - x, x, x respectively, where x is a value greater than or equal to 0 and less than or equal to 1 (0 ≤ x ≤ 1). The value of x is related to the magnitude of the current that the actual application system wants to generate. Generally, the value is 0.5 < x ≤ 0.6. For example, the default value can be taken as 0.5. The specific value of x depends on the characteristics of the motor and the phase current sensor.

[0050] The shutdown self-test process 300 then includes, in box 330, causing the first gate driver GDU1 and the second gate driver GDU2 to drive the first bridge arm module B61 and the second bridge arm module B62 according to the duty cycles specified by the first three-phase duty cycle instructions DTu1, DTv1, DTw1 and the second three-phase duty cycle instructions DTu2, DTv2, DTw2 for a first time period, and during the first time period, detecting the first group of phase current values ​​PCu1, PCv1, PCw1 collected by the first phase current sampler S1 and the second group of phase current values ​​PCu2, PCv2, PCw2 collected by the second phase current sampler S2.

[0051] The shutdown self-test process 300 also includes, in box 340, after the first time period, the first MCU MCU1 and the second MCU MCU2, while ensuring that the sum of the duty cycle of each phase in the first three-phase duty cycle instruction DTu1, DTv1, DTw1 and the duty cycle of the corresponding phase in the second three-phase duty cycle instruction DTu2, DTv2, DTw2 sent by the second MCU MCU2 is still 1, respectively adjusting the duty cycle specified by the first three-phase duty cycle instruction DTu1, DTv1, DTw1 and the duty cycle specified by the second three-phase duty cycle instruction DTu2, DTv2, DTw2.

[0052] For example, the first MCU MCU1 can adjust the duty cycle of DTu1, DTv1, and DTw1 from x, 1-x, 1-x to 1-x, x, 1-x, while the second MCU MCU2 can adjust the duty cycle of DTu2, DTv2, and DTw2 from 1-x, x, x to x, 1-x, x.

[0053] The shutdown self-test process 300 also includes, in box 350, causing the first gate driver GDU1 and the second gate driver GDU2 to drive the first bridge arm module B61 and the second bridge arm module B62 according to the adjusted duty cycles specified by the first three-phase duty cycle instructions DTu1, DTv1, DTw1 and the second three-phase duty cycle instructions DTu2, DTv2, DTw2 for a second time period, and during the second time period, respectively detecting the first group of phase current values ​​PCu1', PCv1', PCw1' collected by the first phase current sampler S1 and the second group of phase current values ​​PCu2', PCv2', PCw2' collected by the second phase current sampler S2.

[0054] The first time period and the second time period can be determined according to actual applications, and are generally several tens of milliseconds, such as 50 to 100 milliseconds (including endpoint values).

[0055] The shutdown self-test process 300 also includes, in box 360, determining the largest one of the phase current values ​​PCu1, PCv1, PCw1 detected during the first time period and the phase current values ​​PCu1', PCv1', PCw1' detected during the second time period, and determining the largest one of the phase current values ​​PCu2, PCv2, PCw2 detected during the second time period and the phase current values ​​PCu2', PCv2', PCw2' detected during the second time period.

[0056] The shutdown self-test process 300 also includes, in box 370, determining whether the first related breaker PD1 is successfully shut down based on whether the largest one of PCu1, PCv1, PCw1 and PCu1', PCv1', PCw1' reaches the current threshold A, and determining whether the second related breaker PD2 is successfully shut down based on whether the largest one of PCu2, PCv2, PCw2 and PCu2', PCv2', PCw2' reaches the current threshold A.

[0057] If the largest current value among PCu1, PCv1, PCw1, and PCu1', PCv1', and PCw1' reaches current threshold A, the first-related circuit breaker PD1 is determined to have failed. Otherwise, the first-related circuit breaker PD1 is determined to have successfully shut down. Similarly, if the largest current value among PCu2, PCv2, PCw2, and PCu2', PCv2', and PCw2' reaches current threshold A, the second-related circuit breaker PD2 is determined to have failed. Otherwise, the second-related circuit breaker PD2 is determined to have successfully shut down. This completes the shutdown self-test of the related circuit breakers.

[0058] In one embodiment, the current threshold A is set to at least twice the maximum of the zero-drift current values ​​of each phase of the first motor winding and the second motor winding. In another embodiment, the current threshold A is determined by a current threshold determination step. The current threshold determination step includes: with the first and second motor circuit breakers PD1 and PD2 both closed, setting the three-phase duty cycle of each of the first and second motor windings to 0.5, then adjusting the three-phase duty cycle of the first and second motor windings until the actual corresponding phase current increases to a level where the presence of current can be clearly determined; and determining the value of the actual corresponding phase current as the current threshold A.

[0059] FIG4 shows a flow chart of a self-test process 400 of a related circuit breaker according to an embodiment of the present disclosure.

[0060] When performing the self-test, the self-test is performed on each of the three phases of the first motor winding and the second motor winding in turn, and the phase currently being self-tested is the current target phase. It is determined whether the current value of the current target phase of the first motor winding and the second motor winding is greater than the current threshold. If the current value of the current target phase is greater than the current threshold, the current target phase is successfully attracted, otherwise the current target phase is attracted faultily.

[0061] The pull-in self-test process 400 begins at block 410. At block 410, the first related circuit breaker driver chip PDD1 and the second related circuit breaker driver chip PDD2 send pull-in instructions to the first related circuit breaker PD1 and the second related circuit breaker PD2, respectively.

[0062] The pull-in self-test process 400 includes, in box 420, the first MCU MCU1 sends a first three-phase duty cycle instruction DTu1, DTv1, DTw1 to the first gate driver GDU1, and the second MCU MCU2 sends a second three-phase duty cycle instruction DTu2, DTv2, DTw2 to the second gate driver GDU2, wherein the first three-phase duty cycle instruction DTu1, DTv1, DTw1 specifies the duty cycle of the U phase, V phase, and W phase of the first motor winding, and the second three-phase duty cycle instruction DTu2, DTv2, DTw2 specifies the duty cycle of the U phase, V phase, and W phase of the second motor winding, and the sum of the duty cycle of each phase specified in the first three-phase duty cycle instruction DTu1, DTv1, DTw1 and the duty cycle of the corresponding phase specified in the second three-phase duty cycle instruction DTu2, DTv2, DTw2 is 1.

[0063] The pull-in self-check process 400 then includes, in block 430, with the U-phase as the current target phase during the third time period, in sub-block 431, setting the duty cycles of the U-phase, V-phase, and W-phase of the first motor winding specified in the first three-phase duty cycle commands DTu1, DTv1, DTw1 to x, 1 - x, 1 - x respectively, and setting the duty cycles of the U-phase, V-phase, and W-phase of the second motor winding specified in the second three-phase duty cycle commands DTu2, DTv2, DTw2 to 1 - x, x, x respectively, where 0.5 < x ≤ 0.6; in sub-block 432, causing the first gate driver GDU1 and the second gate driver GDU2 to drive the first bridge arm module B61 and the second bridge arm module B62 according to the duty cycles specified in the first three-phase duty cycle commands DTu1, DTv1, DTw1 and the second three-phase duty cycle commands DTu2, DTv2, DTw2 respectively; in sub-block 433, detecting the first set of phase current values PCu1, PCv1, PCw1 collected by the first phase current sampler S1 and the second set of phase current values PCu2, PCv2, PCw2 collected by the second phase current sampler S2 respectively; in sub-block 434, determining whether the U-phase of the first related breaker PD1 is successfully pulled in based on whether the maximum value of PCu1 in the first set of phase current values PCu1, PCv1, PCw1 reaches the current threshold A, and determining whether the U-phase of the second related breaker PD2 is successfully pulled in based on whether the maximum value of PCu2 in the second set of phase current values PCu2, PCv2, PCw2 reaches the current threshold A.

[0064] The current threshold A is the current value when, with both the first related breaker PD1 and the second related breaker PD2 pulled in, the duty cycles specified in the first three-phase duty cycle commands DTu1, DTv1, DTw1 and the second three-phase duty cycle commands DTu2, DTv2, DTw2 are adjusted to increase the actual phase current to a value where it can be clearly determined whether there is current or not.

[0065] The pull-in self-check process 400 then includes, in block 440, with phase V as the current target phase, during the fourth time period, in sub-block 441, adjusting the duty cycles of the U-phase, V-phase, and W-phase of the first motor winding specified in the first three-phase duty cycle commands DTu1, DTv1, and DTw1 to 1 - x, x, and 1 - x respectively, and adjusting the duty cycles of the U-phase, V-phase, and W-phase of the second motor winding specified in the second three-phase duty cycle commands DTu2, DTv2, and DTw2 to x, 1 - x, and x respectively, where 0.5 < x ≤ 0.6; in sub-block 442, causing the first gate driver GDU1 and the second gate driver GDU2 to drive the first leg module B61 and the second leg module B62 respectively according to the adjusted duty cycles specified in the first three-phase duty cycle commands DTu1, DTv1, DTw1 and the second three-phase duty cycle commands DTu2, DTv2, DTw2; in sub-block 443, detecting the first set of phase current values PCu1, PCv1, PCw1 collected by the first phase current sampler S1 and the second set of phase current values PCu2, PCv2, PCw2 collected by the second phase current sampler S2 respectively; in sub-block 444, determining whether the V-phase of the first contactor PDl is successfully pulled in based on whether the maximum value of PCv1 in the first set of phase current values PCu1, PCv1, PCw1 reaches the current threshold A, and determining whether the V-phase of the second contactor PD2 is successfully pulled in based on whether the maximum value of PCv2 in the second set of phase current values PCu2, PCv2, PCw2 reaches the current threshold A.

[0066] The pull-in self-check process 400 then includes, in block 450, with the W phase as the current target phase, during five time periods, in sub-block 451, adjusting the duty cycles of the U, V, and W phases of the first motor winding specified in the first three-phase duty cycle commands DTu1, DTv1, and DTw1 to 1 - x, 1 - x, and x respectively, and adjusting the duty cycles of the U, V, and W phases of the second motor winding specified in the second three-phase duty cycle commands DTu2, DTv2, and DTw2 to x, x, and 1 - x respectively, where 0.5 < x ≤ 0.6; in sub-block 452, causing the first gate driver GDU1 and the second gate driver GDU2 to drive the first leg module B61 and the second leg module B62 respectively according to the adjusted duty cycles specified in the first three-phase duty cycle commands DTu1, DTv1, DTw1 and the second three-phase duty cycle commands DTu2, DTv2, DTw2; in sub-block 453, detecting the first set of phase current values PCu1, PCv1, PCw1 collected by the first phase current sampler S1 and the second set of phase current values PCu2, PCv2, PCw2 collected by the second phase current sampler S2 respectively; in sub-block 454, determining whether the W phase of the first related breaker PD1 is successfully pulled in based on whether the maximum value of PCw1 in the first set of phase current values PCu1, PCv1, PCw1 reaches the current threshold A, and determining whether the W phase of the second related breaker PD2 is successfully pulled in based on whether the maximum value of PCw2 in the second set of phase current values PCu2, PCv2, PCw2 reaches the current threshold A.

[0067] During the third time period, if the maximum value of PCu1 reaches the current threshold A, the U phase of the first related breaker PD1 is successfully pulled in, otherwise the U phase of the first related breaker PD1 has a pull-in failure; if the maximum value of PCu2 reaches the current threshold A, the U phase of the second related breaker PD2 is successfully pulled in, otherwise the U phase of the second related breaker PD2 has a pull-in failure.

[0068] During the fourth time period, if the maximum value of PCv1 reaches the current threshold A, the V phase of the first related breaker PD1 is successfully pulled in, otherwise the V phase of the first related breaker PD1 has a pull-in failure; if the maximum value of PCv2 reaches the current threshold A, the V phase of the second related breaker PD2 is successfully pulled in, otherwise the V phase of the second related breaker PD2 has a pull-in failure.

[0069] During the fifth time period, if the maximum value of PCw1 reaches the current threshold A, the W phase of the first related breaker PD1 is successfully pulled in, otherwise the W phase of the first related breaker PD1 has a pull-in failure; if the maximum value of PCw2 reaches the current threshold A, the W phase of the second related breaker PD2 is successfully pulled in, otherwise the W phase of the first related breaker PD2 has a pull-in failure.

[0070] The third time period, the fourth time period, and the fifth time period are all within the range of 50 to 100 milliseconds (including the endpoint values).

[0071] If the U phase, V phase and W phase of the first-related breaker PD1 are all successfully energized, the first-related breaker PD1 is successfully energized. If the U phase, V phase and W phase of the second-related breaker PD2 are all successfully energized, the second-related breaker PD2 is successfully energized, thereby completing the energization self-test of the first-related breaker PD1 and the second-related breaker PD2.

[0072] In one embodiment, the current threshold A is set to at least twice the maximum of the zero-drift current values ​​of each phase of the first motor winding and the second motor winding. In another embodiment, the current threshold A is determined by a current threshold determination step. The current threshold determination step includes: with the first and second motor circuit breakers PD1 and PD2 both closed, setting the three-phase duty cycle of each of the first and second motor windings to 0.5, then adjusting the three-phase duty cycle of the first and second motor windings until the actual corresponding phase current increases to a level where the presence of current can be clearly determined; and determining the value of the actual corresponding phase current as the current threshold A.

[0073] It should be noted that in the self-test process 400 of the relevant circuit breaker in Figure 4, the U phase, V phase and W phase of the first motor winding and the second motor winding are respectively energized and self-tested. However, in other embodiments, the self-test can be performed in other orders, that is, the order of U phase, V phase and W phase as the current target phases can be adjusted as needed, which is not limited in this application.

[0074] According to the embodiments of the present application, during the shutdown and pull-in self-test processes of the relevant circuit breakers, the voltage applied during the self-test is set to two duty cycles to cause the motor to output DC power, and then a disconnect command is sent to the relevant circuit breaker to check whether current flows through the corresponding two sets of motor windings. For each phase of the motor winding, the duty cycles issued by the first MCU MCU1 and the second MCU MCU2 are ensured to be 1, so that the two sets of motor windings generate currents of equal magnitude and opposite directions, thereby generating opposite torques, which offset each other.

[0075] According to the embodiments of the present application, the self-test processes for the shutdown and engagement of the related circuit breakers enable self-testing of the related circuit breakers in a dual-redundant electric power steering system while ensuring that the total output torque of the vehicle's motor is zero. Furthermore, during the self-test of each set of related circuit breakers, two sets of duty cycles are applied alternately, causing the current direction of two phases of the three-phase winding to be alternating, thus preventing omissions in the self-test of the related circuit breakers during the shutdown and engagement processes.

[0076] FIG5 shows a schematic block diagram of an electronic device 500 used in a vehicle according to an embodiment of the present invention. As shown in FIG5 , in some embodiments, the electronic device 500 used in a vehicle may include a processor 502, a communication module 504, and a memory 506, any two of which are electrically connected directly or indirectly to enable data transmission or interaction. For example, these components may be electrically connected to each other via one or more communication buses or signal lines. The processor 502 may include, but is not limited to, a general-purpose processor (e.g., a central processing unit (CPU), a graphics processing unit (GPU), a network processor (NP), etc.), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, etc. The communication module 504 is used for wired or wireless communication with related devices outside the vehicle 500, and / or wired or wireless communication with other devices in the vehicle. The memory 506 may include, but is not limited to, random access memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, etc., and may be used to store various programs for execution by the processor 502, as well as various intermediate variables and final results generated when the processor 502 executes the programs. For example, the memory 506 in the electronic device 500 may be used to store machine-readable instructions that, when executed by the processor 502, implement the shutdown self-test process and the pull-in self-test process of the relevant circuit breaker as shown in Figures 2 to 4.

[0077] It is understood that the structure shown in Figure 5 is only a schematic diagram of the structure of the electronic device 500, and the electronic device 500 may also include more or fewer components than those shown in Figure 5. The various components shown in Figure 5 may be implemented using hardware, software, or a combination thereof.

[0078] The present invention may be implemented in other specific forms without departing from its spirit and essential characteristics. For example, the algorithms described in the specific embodiments may be modified without departing from the basic spirit of the present invention. Therefore, the present embodiments are to be considered in all respects as illustrative and not restrictive, the scope of the invention is defined by the appended claims rather than the foregoing description, and all modifications coming within the meaning and scope of equivalents of the claims are intended to be included within the scope of the present invention.

Claims

1. A related breaker self - checking control method, applicable to a dual - redundant electric power steering system in a vehicle. The dual - redundant electric power steering system includes a first motor winding and a second motor winding. The method includes: A cooperative control step of cooperatively controlling the first motor winding and the second motor winding so that the total output torque of the first motor winding and the second motor winding is 0; And A related breaker self - checking step of controlling the related breakers of each phase of the first motor winding and the second motor winding to perform related breaker self - checking according to the current values of each phase.

2. The related breaker self-check control method according to claim 1, wherein, The cooperative control step includes: cooperatively setting the duty ratios of the first motor winding and the second motor winding so that the total output torque of the first motor winding and the second motor winding is 0.

3. The relevant breaker self-check control method according to claim 2, wherein, The related breaker self - checking includes turn - off self - checking and / or pull - in self - checking. The related breaker self - checking step includes: Simultaneously turning off / pulling in the related breakers of each phase of the first motor winding and the second motor winding; Collecting the current values of each phase of the first motor winding and the second motor winding; When performing turn - off self - checking, for the first motor winding and the second motor winding, respectively determine whether the maximum value among the current values of each phase is less than the current threshold. If the maximum value is less than the current threshold, the turn - off is successful; otherwise, the turn - off fails. When performing pull - in self - checking, sequentially perform pull - in self - checking for each phase of the three phases of the first motor winding and the second motor winding respectively. And the phase currently being self - checked is the current target phase. Respectively determine whether the current value of the current target phase of the first motor winding and the second motor winding is greater than the current threshold. If the current value of the current target phase is greater than the current threshold, the current target phase is successfully pulled in; otherwise, the current target phase fails to be pulled in.

4. The relevant breaker self-check control method according to claim 3, wherein, When performing turn - off self - checking, The cooperative control step includes: Driving the first motor winding and the second motor winding according to a first pair of three - phase duty ratios and maintaining for a first time period. The first pair of three - phase duty ratios makes the sum of the duty ratio of each phase of the first motor winding and the corresponding phase of the second motor winding equal to 1; and Driving the first motor winding and the second motor winding according to a second pair of three - phase duty ratios and maintaining for a second time period. The second pair of three - phase duty ratios is different from the first pair of three - phase duty ratios, but still makes the sum of the duty ratio of each phase of the first motor winding and the corresponding phase of the second motor winding equal to 1; The related breaker self - checking step includes: During the first time period, respectively collecting the first set of current values of each phase of the first motor winding and the second motor winding; During the second time period, respectively collecting the second set of current values of each phase of the first motor winding and the second motor winding; and For the first motor winding and the second motor winding respectively, determining the maximum value among the first set of current values of each phase and the second set of current values of each phase as the maximum value among the current values of each phase. ​ 5. The relevant breaker self-check control method according to claim 4, wherein, The duty ratios for the three phases of the first motor winding in the first pair of three-phase duty ratios are x, 1 - x, and 1 - x, and the duty ratios for the three phases of the first motor winding in the second pair of three-phase duty ratios are 1 - x, x, and 1 - x, where 0.5 < x ≤ 0.

6.

6. The relevant breaker self-check control method according to claim 4, wherein, Both the first time period and the second time period are in the range of 50 to 100 milliseconds.

7. The related breaker self-check control method according to claim 3, wherein, When performing the pull-in self-check, the collaborative control steps include: Collaboratively setting the duty ratios of the first motor winding and the second motor winding such that the duty ratio of the current target phase of the first motor winding is x, the duty ratios of the other two phases of the first motor winding are both 1 - x, and the duty ratio of the current target phase of the second motor winding is 1 - x, and the duty ratios of the other two phases of the second motor winding are both x, where 0.5 < x ≤ 0.6; and Driving the first motor winding and the second motor winding according to the set duty ratios within a predetermined time period; The relevant breaker self-check steps include: During the predetermined time period, respectively collecting the current values of the current target phases of the first motor winding and the second motor winding.

8. The relevant breaker self-check control method according to claim 7, wherein, The predetermined time period is in the range of 50 to 100 milliseconds.

9. The relevant breaker self-check control method according to any one of claims 3 to 8, wherein, The current threshold is at least twice the maximum value of the zero-drift current values of each phase of the first motor winding and the second motor winding.

10. The relevant breaker self-check control method according to any one of claims 3 to 8 further includes: A current threshold determination step, which includes: Setting the three-phase duty ratios of both the first motor winding and the second motor winding to 0.5; Adjusting the three-phase duty ratios of the first motor winding and the second motor winding until the actual corresponding phase current increases to a level where it can be clearly determined that there is current; and Determining the value of the corresponding phase current as the current threshold.

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