JP2021125890A - Motor control device - Google Patents

Abstract

To continue motor driving control by transition of a self-system to a fail operation state even when an IG signal of the self-system is determined to be in an ON state and an IG signal of another system enters an OFF state.SOLUTION: In a motor control unit having a redundant structure provided with control units of a plurality of systems, in a case where an IG signal of the self-system is in an ON state, when an IG signal of another system is determined to be in an OFF state and the other system transits to an operation stop standby state, a central control unit of the self-system performs control to continue a normal operation state in the self-system until a predetermined time period elapses. After the elapse of the predetermined time period, the self-system transits to a prescribed fail operation state. Accordingly, even when a failure in one of the control systems is determined, drive control of an electric motor can be continued by the other control system.SELECTED DRAWING: Figure 2

Description

The present invention relates to, for example, a motor control device for electric power steering, which has a redundant configuration including a plurality of systems of motor control circuits.

In the electric power steering device, two sets of inverter circuits that independently drive two sets of coil windings provided in the motor are provided, and by making the control circuit other than the inverter circuit a dual system, one system is abnormal. A redundant configuration has been conventionally known in which motor control is continued by the other system that is operating normally even at the time (in the event of a failure).

In addition, as the automatic driving of vehicles progresses, it is required to continue the operation even if the parts of the electronic control unit (ECU) break down. Therefore, some or all of the parts are redundant. The composition is also known.

Patent Document 1 describes the difference in the supply voltage to each microcomputer and the characteristics of the power supply generation circuit even when a plurality of microcomputers are not operated by the same power supply in a device having a redundant configuration and the power supply power supply is an independent configuration. The ON / OFF timing of the power supply to each microcomputer may shift due to variations, etc., which may affect the operation of the microcomputers. In addition, the operation due to the power OFF due to the deviation of the vehicle switch signal information recognized by each microcomputer Considering that the timing of stop determination may be different in each microcomputer, a microcomputer that has received a stop determination signal from one or more other microcomputers stops the operation of its own microcomputer based on the stop determination signal. A motor control device having a uniform operation stop timing is disclosed.

Japanese Unexamined Patent Publication No. 2019-4682

The motor control device described in Patent Document 1 has a complete two-system redundant configuration in which the two systems are composed of two sets of independent elements, but is in a stop standby state due to a failure of the ignition detection circuit of one system (one system). There is a problem that it shifts to the assist stop state). Since the overheat protection waits for cooling in the stop standby state, it may take a long time to shift to the stop state depending on the heat generation situation. In such a case, the normal system cannot transition to the fail operation state, and for example, the period in which the output is greatly reduced may be very long, and the commercial value of the device is deteriorated.

Further, the motor control device of Patent Document 1 has an architecture in which, for example, when the microcomputer of the partner system is stopped due to a failure other than the failure, the own system microcomputer continues to operate in the same manner as in the normal state, so that control is performed based on, for example, master information. When applied to a motor control device for electric power steering, there may be a problem of self-steering due to the motor being driven based on an abnormal command.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is that when the ignition signal of the own system is determined to be ON and the ignition signal of another system is OFF, the own system fails. It is to shift to the state and continue the motor drive control.

The following configuration is provided as a means for achieving the above object and solving the above-mentioned problem. That is, the first exemplary invention of the present application is a motor control device in which a plurality of control systems are configured to be able to communicate with each other as their own system and other systems, and an ignition switch in each of the own system and the other system. The IG voltage value detecting means for detecting the ignition voltage value via the above, the means for determining the ON / OFF state of the ignition signal in the own system and the other system based on the ignition voltage value, and the ON / OFF state of the ignition signal. The central control unit of the own system includes a central control unit that controls each of the plurality of control systems to any one of a normal operation state, an operation stop standby state, and an operation stop state based on the OFF state. When it is determined that the ignition signal of the own system is in the ON state, the ignition signal of the other system is determined to be in the OFF state, and the other system is in the operation stop standby state, a predetermined specified time elapses. It is characterized in that the normal operating state is continued in the own system until.

An exemplary second invention of the present application is an electric power steering control device that has a central control unit provided for each of a plurality of control systems and assists a driver's steering operation of a vehicle or the like. It is characterized by including an electric motor that assists steering and means for driving and controlling the electric motor by the motor control device according to the above-exemplified first invention.

The third exemplary invention of the present application is an electric power steering system, characterized in that the electric power steering control device according to the second exemplary invention is provided.

According to the present invention, in a motor control device having a redundant configuration, motor drive stop due to variation in stop timing of two systems after IG-OFF, false diagnosis and detection are prevented, and motor drive control is reliably continued in the event of an IG failure. can do.

FIG. 1 is a diagram showing a schematic configuration of an electric power steering system equipped with a motor control unit for electric power steering. FIG. 2 is a diagram showing a configuration of a motor control unit according to an embodiment. FIG. 3 is a diagram showing an example of motor drive control in the motor control unit according to the embodiment. FIG. 4 is a diagram showing another example of motor drive control in the motor control unit according to the embodiment. FIG. 5 is a timing chart showing an example of the operation stop sequence of the motor control unit according to the embodiment consisting of two systems. FIG. 6 is a flowchart showing an example of control processing in the motor control unit according to the embodiment. FIG. 7 is a flowchart showing another example of the control process in the motor control unit according to the embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic configuration of an electric power steering system equipped with an electric power steering control device (EPS) as a motor control unit according to an embodiment of the present invention. As shown in FIG. 1, the electric power steering system 10 includes motor control devices 1a and 1b corresponding to two control systems constituting the motor control unit, a steering handle 2 as a steering member, and a rotation shaft connected to the steering handle 2. 3. A pinion gear 6, a rack shaft 7, and the like are provided.

The rotating shaft 3 meshes with a pinion gear 6 provided at its tip. The pinion gear 6 converts the rotational motion of the rotary shaft 3 into a linear motion of the rack shaft 7, and a pair of wheels 5a, 5b provided at both ends of the rack shaft 7 at an angle corresponding to the amount of displacement of the rack shaft 7. Is steered.

The rotating shaft 3 is provided with torque sensors 9a and 9b for detecting the steering torque when the steering handle 2 is operated, and the detected steering torque is sent to the motor control unit 1. The motor control unit 1 generates a motor drive signal based on signals such as steering torque acquired from torque sensors 9a and 9b and vehicle speed from a vehicle speed sensor (not shown), and transmits the signal to an electric motor 15 for electric power steering. Output.

An auxiliary torque for assisting the steering of the steering handle 2 is output from the electric motor 15 to which the motor drive signal is input, and the auxiliary torque is transmitted to the rotating shaft 3 via the reduction gear 4. As a result, the torque generated by the electric motor 15 assists the rotation of the rotating shaft 3, thereby assisting the driver in operating the steering wheel.

Next, the motor control unit according to this embodiment will be described. FIG. 2 is a configuration diagram of a motor control unit according to the present embodiment. As shown in FIG. 2, the motor control unit 1 has a redundant configuration including two control systems (motor control devices 1a and 1b) having the same component (circuit component).

The redundant configuration is not limited to two systems, and it is possible to develop a redundant configuration consisting of multiple systems such as three systems and four systems.

The motor control devices 1a and 1b are composed of a first system and a second system that are independent of each other, and each of the motor control devices 1a and 1b has a control unit (CPU) 12a and 12b. The motor control devices 1a and 1b include an electric motor 15 having a configuration in which two sets of three-phase windings (Ua, Va, Wa) 15a and three-phase windings (Ub, Vb, Wb) 15b are coaxially provided. It has a double inverter configuration consisting of two sets of inverter circuits 14a and 14b that supply drive current to each of the two sets of three-phase windings. The electric motor 15 is, for example, a three-phase brushless DC motor.

The electric motor 15 is equipped with rotation sensors 11a and 11b that detect the rotation position of the rotor of the motor corresponding to the three-phase windings 15a and 15b, respectively. The output signals from the rotation sensors 11a and 11b are transmitted to the CPUs 12a and 12b as rotation information, respectively.

Each of the motor control devices 1a and 1b independently drives the electric motor 15 based on the sensor output from the sensors, the drive / control signal, and the like. Here, the component including the motor control device 1a and the three-phase winding 15a is referred to as the first system, and the component including the motor control device 1b and the three-phase winding 15b is referred to as the second system.

The motor control device 1a constituting the first system generates a motor drive signal from control signals from, for example, a control unit (CPU) 12a composed of a microprocessor and a CPU 12a, which controls the entire device, and functions as an FET drive circuit. The inverter control unit 13a and the inverter circuit 14a, which is a motor drive unit that supplies a drive current to the three-phase windings (Ua, Va, Wa) 15a of the electric motor 15, are provided.

Similar to the motor control device 1a, the motor control device 1b constituting the second system generates a motor drive signal from the control signals (CPU) 12b and the CPU 12b that control the entire device, and serves as an FET drive circuit. A functioning inverter control unit 13b and an inverter circuit 14b for supplying a predetermined drive current to the three-phase windings (Ub, Vb, Wb) 15b of the electric motor 15 are provided.

The CPUs 12a and 12b of the motor control devices 1a and 1b are configured to enable real-time mutual communication. Further, the motor control devices 1a and 1b are connected to other control units (ECU) via CAN signal lines (CAN communication bus) 27H and 27L connected to an in-vehicle network (CAN) that exchanges various vehicle information. Data communication is performed between the two using the CAN protocol.

The CAN signal lines 27H and 27L are two-wire systems each consisting of the CAN-H line 27Ha and CAN-L line 27La constituting the first system and the CAN-H line 27Hb and CAN-L line 27Lb constituting the second system. Communication line.

A power source (+ B) for driving a motor is supplied to the inverter circuit 14a from an external battery BT via a filter (not shown) and a power supply relay that absorb noise and the like contained in the power supply to smooth the power supply voltage. Similarly, the inverter circuit 14b is supplied with a power source (+ B) for driving the motor from the external battery BT via a filter and a power supply relay (not shown).

The inverter circuit 14a is a FET bridge circuit composed of semiconductor switching elements (FETs) corresponding to each of the three-phase windings (Ua, Va, Wa) 15a of the electric motor 15. Further, the inverter circuit 14b is a FET bridge circuit composed of semiconductor switching elements (FETs) corresponding to each of the three-phase windings (Ub, Vb, Wb) 15b of the electric motor 15.

These switching elements (FETs) are also called power elements, and for example, semiconductor switching elements such as MOSFET (Metal-Oxide Semiconductor Field-Effect Transistor) and IGBT (Insulated Gate Bipolar Transistor) are used.

One end of the ignition switch (IG-SW) 31 is connected to the battery BT, and the other end is connected to the power supply management units 21a and 21b of the power supply units 20a and 20b, respectively. The other end of the IG-SW31 is further connected to the IG voltage detection units 24a and 24b.

The power supply management units 21a and 21b activate the power supply units 20a and 20b when the ignition switch (IG-SW) 31 is ON or when the self-holding signals 35a and 35b from the CPUs 12a and 12b are ON. The power supply units 20a and 20b convert the battery voltage + B supplied from the battery BT into a predetermined voltage (for example, logic level voltage + 5V), and convert it into the control units (CPU) 12a and 12b, the inverter control unit 13a, It is supplied as an operating power source for a control circuit such as 13b.

The IG voltage detection units 24a and 24b perform AD conversion of the ignition (IG) voltage value, and input the converted digital voltage value to the CPUs 12a and 12b as the actual voltage value of the IG voltage in each of the first system and the second system. do. The IG voltage detection units 24a and 24b may be arranged in the CPUs 12a and 12b, respectively.

The battery (BT) voltage detection units 29a and 29b input the battery voltage (+ B) of the battery BT, perform AD conversion, and input the converted digital voltage value to the CPUs 12a and 12b as the battery (BT) voltage value. Further, the BT voltage detection units 29a and 29b determine whether or not the battery voltage value is equal to or higher than the specified voltage value (whether or not the voltage value that enables the control circuit or the like to operate is satisfied).

Next, the operation of the motor control unit according to the present embodiment will be described. 3 and 4 show an example of a motor drive control procedure in the motor control unit according to the present embodiment.

In the motor drive control shown in FIG. 3, in the motor control device 1a of the first system, the CPU 12a calculates the target torque Tt calculated from the input indicated torque (steering torque) Tq by the motor control device of the second system by inter-CPU communication. It is transmitted to the CPU 12b of 1b.

As a result, the first system drives and controls the electric motor 15 based on the torque control information based on the target torque Tt calculated by the own system, and the second system directly uses the target torque Tt calculated by the first system as the torque control information. To drive and control the electric motor 15.

On the other hand, in the motor drive control shown in FIG. 4, in the motor control device 1a of the first system, the target torque Tt1 calculated by the CPU 12a based on the indicated torque Tq1 is determined by the inter-CPU communication, as in the example of FIG. Although it is transmitted to the CPU 12b of the two systems of motor control devices 1b, the CPU 12b also calculates the target torque Tt2 from the input indicated torque Tq2 in the second system of motor control devices 1b.

As a result, the CPU 12a of the first system drives and controls the electric motor 15 using the target torque Tt1, and the CPU 12b of the second system has the target torque Tt1 and the CPU 12b transmitted from the first system by inter-CPU communication. One of the calculated target torques Tt2 is selected by the selection unit to drive and control the electric motor 15.

FIG. 5 is a timing chart showing an example of an operation stop sequence of the motor control unit according to the present embodiment including two systems.

The motor control unit 1 shown in FIG. 2, when the ignition switch (IG-SW) 31 at timing _{t 0} shown in FIG. 5 is a OFF, IG voltage of the first system, as shown in FIG. 5 is a timing _{t 0} In, for example, it drops from 14V to 0V. Then, at _{the timing t 1} after the lapse of the time T1 from _{the timing t 0} , the IG state (also referred to as an IG signal), which is the state of the ignition switch, transitions from ON to OFF.

Then, the timing t ₂ after time T2 has elapsed from the timing t _1, the normal operating state of the first system (motor drive state) is completed. After that, the first system shifts to the stopped state (also referred to as power stop or reset) through the stop standby state. That is, in the first system, the time from IG-OFF to reset is T1 + T2 + stop standby time. In the stop standby state, for example, waiting for the completion of cooling of overheat protection is performed. Therefore, depending on the heat generation situation, it may take several minutes to shift to the stopped state.

On the other hand, in the second system, when the ignition switch (IG-SW) 31 is turned off, the IG voltage drops from 14V to 0V at _{the timing t 0} ', which is time Tx later than the _{above timing t 0.} Then, the IG state transitions from ON to OFF from the timing t _{0 ′ to the timing t 1} ′ after the lapse of the time T1.

Even if the input of the IG signal to the electronic control unit ECU is redundant, for example, the wiring from the IG-SW to the ECU, the part of the vehicle where the IG signal input is branched, and the like, the first system and the second system It is assumed that an IG timing error will occur between the systems and there will be an uncontrollable period during which motor drive control cannot be executed. In addition, when the motor control information calculated in one system is used for motor control in the other system, it is assumed that there will be a period of time controlled by the control information of the system that has transitioned to the stop standby state due to the IG timing error. ..

Further, if the time from the transition to the stop standby state to the stop of the inter-CPU communication is too short, another system may erroneously detect the inter-CPU communication diagnosis.

Therefore, the IG timing error (maximum error) between the first system and the second system is defined as the above time Tx. Then, starting from the occurrence of a failure of a component constituting the motor control unit 1, a time interval FTTI (Fault Tolerant Time Interval) until it is considered that a dangerous event (for example, self-steering) such as braking failure actually occurs in the vehicle. ) Is taken into consideration, the smaller of the IG timing error and the FTTI is defined as Tx.

As a measure to extend FTTI, for example, the hazard level is reduced to Loss of Assist (LOA) by setting the control information (target torque Tt described above) to be transmitted to another system to 0 in the communication between CPUs. Treatment may be given. In that case, regardless of the FTTI, consideration may be given to ensuring the commercial value of the device by limiting the time so that the user does not feel the influence of the vehicle so much.

In the second system, the timing t ₃ after time T3 has elapsed from the timing t _{1 ',} a normal operation state (a motor drive state) is completed. After that, as in the first system, it shifts to the stopped state (reset) through the stop standby state. Therefore, the time from IG-OFF to reset in the second system is T1 + T3 + stop standby state period.

In both the first system and the second system, communication between control units (CPU) is possible in a normal state (motor drive state) and a stop standby state.

In the operation stop sequence shown in FIG. 5, if the IG timing error Tx between the systems of the motor control unit is within the time of the stop standby state, erroneous detection of the IG state does not occur in the communication between the CPUs of the systems. However, when the IG timing error Tx is longer than expected, the above-mentioned uncontrollable period occurs, erroneous detection of inter-CPU communication diagnosis, and the like occur.

Therefore, in the motor control unit according to the present embodiment, by performing the following controls, an uncontrollable period occurs due to the above-mentioned variation in stop timing after IG-OFF in the motor control unit having a redundant configuration, and communication between CPUs occurs. Avoid false detection of diagnosis.

FIG. 6 is a flowchart showing an example of control processing in the motor control unit according to the present embodiment. Here, for convenience, of the two systems of motor control devices constituting the motor control unit 1, the first system is the own system and the second system is the other system.

In step S11 of FIG. 6, the control unit (CPU) 12a of the motor control device 1a of the first system, which is the own system, sets the IG state of the own system to IG-ON based on the voltage detection result by the IG voltage detection unit 24a. Whether it is IG-OFF or IG-OFF is determined. If the IG state is IG-ON, the CPU 12a of the own system performs a normal operation (motor drive control) in step S13.

In the subsequent step S15, the CPU 12a of the own system determines whether the IG state of the other system is IG-ON or IG-OFF by inter-CPU communication with the control unit (CPU) 12b of the other system.

When the IG state of the other system is determined to be IG-OFF, the CPU 12a of the own system determines in step S17 whether or not the inter-CPU communication with the CPU 12b of the other system is continuing. If it is determined that the CPU-to-CPU communication is not continuing, it is assumed that the other system is already in the operation stop state, and the own system shifts to the predetermined fail operation state (step S23).

When the communication between CPUs is continued, in step S19, it is determined whether or not the other system has shifted to the stop standby state. If the other system has shifted to the stop standby state, the CPU 12a of the own system determines in step S21 whether or not a predetermined predetermined time has elapsed. Therefore, the normal motor drive control by the CPU 12a of the own system is continued until the specified time elapses.

When the above-mentioned specified time has elapsed, the CPU 12a of the own system shifts the own system to a predetermined fail operation state in step S23. As a fail operation, the CPU 12a sets, for example, a target torque for maintaining the motor drive output of its own system at 50% of the normal time for the inverter control unit 13a.

If the IG state of the own system is determined to be IG-OFF in step S11, the CPU 12a shifts the own system to the stop standby state in step S25, and shifts to the stop state (power down) in step S27. ..

By resetting, the CPU 12a of the own system and the CPU 12b of the other system turn off the self-holding signals 35a and 35b. As a result, the generation of the voltage + 5V by the power supply units 20a and 20b is stopped. Therefore, by turning on the ignition switch (IG-SW) on the vehicle side, the CPU 12a of the own system and the CPU 12b of the other system can be restarted. When the self-holding signals 35a and 35b are turned on by the restart operation of the IG-SW and both systems can be started, normal motor drive control is executed in both systems.

If the ignition signal of the own system is determined to be in the OFF state before the elapse of the predetermined predetermined time described above, the own system may be shifted to the operation stop standby state. By doing so, it can be determined that the ignition signal is turned off while there is no variation in the stop timing of the ignition signal in both the own system and the other system.

FIG. 7 is a flowchart showing another example of the control process in the motor control unit according to the present embodiment. FIG. 6 is a process corresponding to the transition to the fail operation state in the normal system, but here, the control process in the stopped system will be described.

In step S31 of FIG. 7, the control unit (CPU) 12a of the motor control device 1a of the first system (own system) determines the IG state of the own system based on the voltage detection result by the IG voltage detection unit 24a. If the IG state is IG-OFF, the CPU 12a of the own system transitions the own system to the stop standby state in step S33.

In the subsequent step S35, the CPU 12a of the own system sets the control information calculated by the own system and transmitted to the system by inter-CPU communication to a specified value. As a result, when the own system enters the stop standby state and the control information is not updated, and the control information is transmitted to the other system by inter-CPU communication, the other system executes the motor drive control with the control information as it is. You can avoid the problem of getting rid of it.

In this case, for example, by setting the control information transmitted from the own system to another system to 0 and lowering the hazard level to assist loss (LOA), the time interval FTTI until a dangerous event occurs can be extended.

In step S37, the CPU 12a of the own system determines whether or not the specified time has elapsed. When the specified time has elapsed, the CPU 12a of the own system stops the communication between the CPUs in step S39. As a result, the other system, which is the partner system, is shifted to the predetermined fail operation state (step S41).

As described above, according to the control process shown in FIG. 7, although the period of assist loss (LOA) may be longer than the variation in the stop timing of the ignition signal, the control process is performed with a simpler control logic than in FIG. You can.

In the state where the CPU-to-CPU communication is continued without performing the process of step S39, it is not possible to shift to the fail operation state. Therefore, by stopping the communication between CPUs, if the control information is not shared between both systems (that is, control is performed by one system 50%: the other system 50%), if one system is in the operation stopped state. Without it, the problem that the other system does not enter the fail operation state and continues to output 50% can be solved.

As described above, the motor control unit according to the present embodiment has a redundant configuration having control units of a plurality of systems (for example, two systems), and the ignition signal of the own system is ON in the central control unit of the own system. At this time, if the ignition signal of the other system is determined to be in the OFF state and the other system is in the operation stop standby state, control is performed to continue the normal operation state in the own system until a predetermined specified time elapses. .. In addition, after the predetermined specified time has elapsed, the own system shifts to the predetermined fail operation state.

Due to such control, in a vehicle or the like composed of a plurality of control systems, one side is caused by variations in the stop timing of the ignition signal via the ignition switch in each control system, differences in the control state in the central control unit of each control system, and the like. Even if it is determined that the control system of the above is out of order, the drive control of the electric motor can be continued by the other control system.

Therefore, even if the ignition signal is not detected or erroneously detected in the other control system, the drive control of the motor can be continued in the own system in response to the ignition signal. Further, even if the control system of the other party is in the operation stop standby state, the electric motor can be driven and controlled by the own system. Furthermore, since the timing of transition to the fail operation state can be determined in a normal system, the transition to the fail operation can be smoothly performed.

Therefore, even if a failure occurs in one system, the motor drive can be continued by driving the electric motor by the other system with at least 50% of the output torque when the entire control system is normal.

For example, in the motor control device for electric power steering, by setting the motor control device having the above-mentioned redundant configuration to drive and control the electric motor, the uncontrollable period due to the variation in the stop timing of the two systems after IG-OFF It is possible to prevent the occurrence, false detection of diagnosis, etc., and to reliably continue the motor drive control in the event of an IG failure.

Further, for example, in the electric power steering system provided with the above-mentioned motor control device for electric power steering, it is possible to continue assisting the steering drive control in the same manner as described above.

The present invention is not limited to the above embodiment, and various modifications are possible. Hereinafter, a modified example will be described.

<Modification example 1>
In the control system, the time from the start of the operation stop standby state to the operation stop state (power down) may be longer than a predetermined specified time.

That is, by prolonging the time during which the operation stop standby state is maintained in the remote system, the remote system stops self-holding from the stop standby state after the specified time elapses, and the control unit (CPU) is powered down to the CPU. It is possible to prevent the inter-communication from being erroneously detected as a failure, and to notify the other system by inter-CPU communication that the other system is in the operation stop standby state with IG-OFF.

<Modification 2>
In the electric power steering control device (EPS) as the motor control unit described above, the signal line of the IG signal (for example, the signal line connecting the battery BT and the IG-SW31) branches in the EPS to reach each system. There is a pattern and a pattern that branches outside the EPS to reach each system.

Therefore, depending on the part where the IG signal wiring in the vehicle fails, even if there is no IG signal input in both the first system and the second system of the motor control unit, other electronic control units (Electronic) included in the vehicle system. It is assumed that the Control Unit (ECU) has a normal ignition signal input.

Even when there is no IG signal input in both systems as described above, the following processing can be performed because the vehicle system is not IG-OFF.

As the first process, for example, when the ignition signal and the CAN information by CAN (Controller Area Network) communication are used together by the control unit (CPU) to identify the disconnection failure of the ignition switch and the ignition signal is in the OFF state. If it is determined that there is no CAN diagnosis, CAN diagnosis cannot be performed in each control system because there is no input of an ignition signal to each control system. Therefore, normal motor drive control may be continued without using CAN information. .. If only one system fails, the ignition voltage value may be acquired from the other system by communication between CPUs and replaced with that value.

Further, since CAN information is not used, motor drive control in which the vehicle speed is fixed to a constant value may be performed, especially when the EPS output is suppressed during high-speed traveling of the vehicle.

By performing such processing, it is possible to eliminate the influence of deterioration in the reliability of CAN information due to the inability to use the IG signal, which is a condition for carrying out the diagnosis of CAN.

As a second process when there is no IG signal input in both systems, for example, when the control unit (CPU) identifies a disconnection failure of the ignition switch and determines that the ignition signal is not in the OFF state, CAN The range of the ignition voltage value, which is the diagnosis execution condition of the CAN diagnosis by the diagnosis unit, may be changed, and the motor drive control of the control system may be continued by using the CAN information.

By disabling the determination of the IG voltage and changing the execution conditions of the CAN diagnosis in this way, it is possible to control the drive of the electric motor using the CAN information. In addition, by enabling CAN diagnosis, steering assist (electric power steering control) based on the ADAS command value of the advanced driver assistance system (ADAS) that provides various driving assistance is stopped, and the ADAS output is lost. You can avoid that.

As a third process when there is no IG signal input in both systems, for example, a battery voltage value detecting means for detecting the voltage value of the battery serving as the drive power source of the control system is provided, and the ignition switch is disconnected by the control unit (CPU). When a failure is identified and it is determined that the ignition signal is not in the OFF state, the ignition voltage value range is replaced with the battery voltage value range to determine the diagnostic execution conditions for CAN diagnosis, and the CAN information is used. The motor drive control of the control system may be continued.

As described above, by determining the diagnosis execution condition of the CAN diagnosis by using the voltage value of the battery instead of the IG voltage, the drive control of the electric motor using the CAN information becomes possible.

<Modification example 3>
The failure record can be processed as follows. That is, in step S21 of FIG. 6, when the own system shifts to the predetermined fail operation state, no failure record is left, and the other system that has shifted to the operation stop standby state turns on the ignition switch again in step S23. If it does not start due to the operation, a failure record may be recorded.

For example, when the above-mentioned FTTI is smaller than the predetermined time, the failure shifts to the predetermined fail operation state at the timing after the FTTI, so that a failure record is recorded if the failure is within the range that can normally occur (accidental failure). No.

Although the process shifts to a provisional fail operation within the FTTI, the warning light (WLP) is not turned on and the failure record is not performed because the IG timing deviation may normally occur depending on the variation. After the specified time has elapsed, the WLP may be turned on and the failure may be recorded.

On the other hand, if only one system shifts to the operation stop standby state and does not start even by re-IG-ON, the normal system can detect the IG failure (true failure) of one system, and in that case, the failure record is recorded. Motor drive control can be continued, leaving it.

<Modification example 4>
When the other system that has been in the operation stop standby state becomes IG-ON by restarting the ignition switch in step S23 of FIG. 6, it may be returned to the normal operation state by the own system and the other system. .. As a result, motor drive control by both the own system and the other system can be continued.

Further, if the ignition signal is determined to be the OFF state after the own system shifts to the predetermined fail operation state in step S21 of FIG. 6, the operation stop standby state may be shifted.

By doing so, it is possible to determine that there is an IG failure in both the own system and the other system, shift to the operation stop, and start the process of waiting for the start by the IG-ON operation again.

1 Motor control unit 1a, 1b Motor control device 2 Steering handle 3 Rotating shaft 4 Reduction gear 6 Pinion gear 7 Rack shaft 9a, 9b Torque sensor 10 Electric power steering system 11a, 11b Angle sensor 12a, 12b Control unit (CPU)
13a, 13b Inverter control unit 14a, 14b Inverter circuit 15 Electric motor 15a, 15b Three-phase winding 19a, 19b CANI / F
20a, 20b Power supply unit 21a, 21b Power supply management unit 24a, 24b IG voltage detection unit 27H, 27L CAN signal line 27Ha, 27Hb CAN-H line 27La, 27Lb CAN-L line 29a, 29b Battery (BT) voltage detection unit 31 Ignition Switch (IG-SW)
35a, 35b Self-holding signal BT battery

Claims (14)

A motor control device in which multiple control systems are configured to be able to communicate with each other as their own system and other systems.
An IG voltage value detecting means for detecting an ignition voltage value via an ignition switch in each of the own system and the other system, and
A means for determining the ON / OFF state of the ignition signal in the own system and the other system based on the ignition voltage value, and
A central control unit that controls each of the plurality of control systems to one of a normal operation state, an operation stop standby state, and an operation stop state based on the ON / OFF state of the ignition signal.
With
The central control unit of the own system determines that the ignition signal of the own system is in the ON state, determines that the ignition signal of the other system is in the OFF state, and shifts the other system to the operation stop standby state. If so, the motor control device that continues the normal operating state in the own system until a predetermined specified time elapses. The motor control device according to claim 1, wherein the central control unit shifts its own system to a predetermined fail operation state after the lapse of the predetermined predetermined time. The motor control device according to claim 1, wherein when the central control unit determines that the ignition signal of the own system is in the OFF state before the lapse of the predetermined predetermined time, the central control unit shifts the own system to the operation stop standby state. .. The motor control device according to claim 1, wherein the time from the start of the operation stop standby state to the operation stop state is made longer than the predetermined specified time. A CAN diagnosis unit that performs CAN diagnosis on the received data by CAN (Controller Area Network) communication with the central control unit, and a CAN diagnosis unit.
A means for identifying a disconnection failure of the ignition switch by using the ignition signal and CAN information by the CAN communication in combination, and
With more
When the ignition signal is not input to the plurality of control systems, the central control unit identifies the disconnection failure of the ignition switch and determines that the ignition signal is not in the OFF state, the CAN information. The motor control device according to claim 1, wherein the drive control of the control system is continued without using the above. When the central control unit identifies a disconnection failure of the ignition switch and determines that the ignition signal is not in the OFF state, the range of the ignition voltage value which is a diagnosis execution condition for CAN diagnosis in the CAN diagnosis unit. 5. The motor control device according to claim 5, wherein the CAN information is used to continue the drive control of the control system. Further provided with a battery voltage value detecting means for detecting the voltage value of the battery serving as the drive power source of the control system, the present invention is further provided.
When the central control unit identifies a disconnection failure of the ignition switch and determines that the ignition signal is not in the OFF state, the central control unit replaces the range of the ignition voltage value with the range of the voltage value of the battery and said the CAN. The motor control device according to claim 5, wherein the diagnosis execution condition of the diagnosis is determined, and the drive control of the control system is continued by using the CAN information. If the own system shifts to the predetermined fail operation state, no failure record is left, and if the other system that has shifted to the operation stop standby state does not start even by the re-ON operation of the ignition switch. The motor control device according to claim 2, which keeps a failure record. The second aspect of claim 2, wherein when the other system that has been in the operation stop standby state is turned on by restarting the ignition switch, the own system and the other system return to the normal operation state. Motor control device. The motor control device according to claim 2, wherein the central control unit shifts to the operation stop standby state when the ignition signal is determined to be an OFF state after the own system shifts to the predetermined fail operation state. One control system of the plurality of control systems performs motor drive control based on the control information calculated by the own system, and the other system, which is the other control system, uses the control information calculated by the one control system. The motor control device according to claim 1, wherein the motor drive control is performed based on the above. When the ignition signal of the own system is determined to be in the OFF state and the own system shifts to the operation stop standby state, the central control unit of the own system sets the control information for the other system to a specified value and determines. The motor control device according to claim 1, wherein the mutual communication with the central control unit of the other system is stopped after the specified time has elapsed. It is an electric power steering control device that has a central control unit provided for each of a plurality of control systems and assists the steering wheel operation of a driver such as a vehicle.
An electric motor that assists the driver in steering and
A means for driving and controlling the electric motor by the motor control device according to any one of claims 1 to 12.
An electric power steering control device equipped with. An electric power steering system including the electric power steering control device according to claim 13.

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