JP4882528B2 - Control device for electric power steering device - Google Patents

Description

  The present invention relates to a steering assist control mechanism having an electric motor for applying a steering assist force to a steering system, an abnormality detection means for detecting an abnormality of the auxiliary control steering mechanism, and the steering assist control steering mechanism using the abnormality detection means. The present invention relates to a control device for an electric power steering apparatus comprising abnormality data storage means for storing the abnormality analysis data in a storage means when an abnormality is detected.

As a control device for a conventional electric power steering apparatus, for example, a data detection means for detecting data usable for failure analysis of a torque sensor, a temporary storage means for temporarily storing data detected by the data detection means, and a temporary storage Failure analysis by writing only the data when the steering assist command exceeds the specified value among the data stored in the means, that is, the data when the steering wheel is actually operated by the driver to the storage memory Unnecessary data is saved, only useful data is saved to save storage memory capacity, and the storage memory is composed of overwriting memory and non-volatile memory for permanent storage, and temporary storage means For permanent storage only when the size of the data stored in exceeds the set range, that is, when there is a high possibility that some abnormality has occurred. Electric power steering torque sensor so as to add stored in non-volatile memory is known (e.g., see Patent Document 1).
Japanese Unexamined Patent Publication No. 2000-337777 (first page, eleventh page, FIG. 12)

  However, in the conventional example described in Patent Document 1, analysis data is stored in the permanent storage nonvolatile memory only when there is a high possibility that some abnormality has occurred. When the storable number of storage nonvolatile memories is exceeded, overwriting is performed in the permanent storage nonvolatile memory, and there is an unsolved problem that the initial analysis data is erased.

That is, when a user notices a failure of the torque sensor and asks a dealer or repair shop to repair, if the abnormality exceeds the number of times that can be stored in the permanent storage memory, including during repair work, the first analysis is performed. There is an unresolved problem that the initial anomaly data necessary for the analysis is lost because the data is overwritten, and the anomaly analysis is hindered.
Therefore, the present invention has been made paying attention to the unsolved problems of the above conventional example, and provides a control device for an electric power steering device that can reliably store initial abnormality analysis data necessary for failure analysis. It is intended to provide.

In order to achieve the above object, a control device for an electric power steering apparatus according to claim 1 includes a steering assist control mechanism including an electric motor that applies a steering assist force to a steering system, and the operation of the steering assist control mechanism. When an abnormality is detected by an initial abnormality detecting means for detecting an abnormality at the start, a constant abnormality detecting means for always detecting an abnormality after the operation of the steering control mechanism is started, and an initial abnormality detecting means and the constant abnormality detecting means. An abnormality data storage means for storing abnormality analysis data including time series data for analyzing the abnormality in the storage means, and the storage means individually corresponds to the initial abnormality detection means and the normal abnormality detection means. The overwriting prohibition storage area for initial abnormality and normal abnormality for prohibiting overwriting of the abnormality analysis data, and for initial abnormality and constant abnormality for overwriting and storing the abnormality analysis data And the abnormal data storage means stores the initial abnormality overwriting prohibition storage area when the abnormality of the steering assist control mechanism detected by the initial abnormality detection means is initial abnormality analysis data. When the initial abnormality analysis data is stored for the second and subsequent times, the abnormality of the steering assist control mechanism stored in the initial abnormality overwriting storage area and detected by the normal abnormality detection means is the first abnormality analysis data. Sometimes it is stored in the always-abnormal overwrite prohibition storage area, and is stored in the always-abnormal overwrite-permitted storage area when it is the second and subsequent always-abnormality analysis data. .

According to a second aspect of the present invention, there is provided the control device for the electric power steering apparatus according to the first aspect , wherein the abnormality data storage means holds abnormality analysis data for a predetermined time before and after the abnormality is detected in time series. It is characterized by being configured.
In addition, the controller of an electric power steering apparatus according to claim 3, characterized in that in the invention of claim 2, wherein the abnormality analysis data is time-series detection period comprising a first predetermined time to detect the continued abnormal state It is characterized by comprising data and time-series data of a fixed period from the end of the detection period to a second predetermined time.

Still further, a control device for an electric power steering apparatus according to a fourth aspect is the invention according to any one of the first to third aspects, wherein the initial abnormality detection means is a torque detection means included in the steering assist control mechanism. Initial abnormality detection, initial abnormality detection of the control means included in the steering assist control mechanism, initial abnormality detection of the current detection means included in the steering assist control mechanism, initial abnormality detection of the electric motor included in the steering assist control mechanism, One or more of the initial abnormality detection of the power supply system and the initial abnormality detection of the storage device are configured to be performed.

The control device for an electric power steering apparatus according to claim 5, in any one invention of claims 1 to 4, wherein the constant abnormality detecting means is always abnormality of the torque detection means included in said steering assist control mechanism Detection, continuous abnormality detection of the control means included in the steering assist control mechanism, constant abnormality detection of the current detection means included in the steering assist control mechanism, constant abnormality detection of the electric motor included in the steering assist control mechanism, the steering The auxiliary control mechanism is configured to perform any one or a plurality of constant abnormality detection of the vehicle speed detection means and constant abnormality detection of the power supply system.

Furthermore, the control apparatus for an electric power steering apparatus according to claim 6, in any one invention of claims 1 to 5, initially stored in said initial abnormality overwrite prohibition storage area and always anomaly overwrite prohibition storage area Data amount management means for managing the data amount, and whether or not the abnormality analysis data can be stored based on the data amount managed by the data amount management means when the abnormality analysis data is next generated It is characterized by comprising storage data adding means for determining and storing new abnormality analysis data in the initial abnormality overwriting prohibition storage area and the normal abnormality overwriting prohibition storage area when it can be determined and stored.
Furthermore, in the control device for an electric power steering apparatus according to claim 7 , in the invention of claim 6 , the data management means is stored in the initial abnormality overwrite prohibition storage area and the constant abnormality overwrite prohibition storage area. The data amount is stored and managed in a nonvolatile memory.

According to the invention of 請 Motomeko 1, the initial abnormal detection unit, and detects the operation start time of the abnormality of the steering assist control mechanism, an always abnormality detecting means, detecting an abnormality of the after start of operation of the steering assist control mechanism The abnormality detected by the initial abnormality detection means and the normal abnormality detection means is individually set in the initial abnormality overwrite prohibition storage area, the initial abnormality overwrite allowable storage area, the constant abnormality overwrite overwrite storage area, and the normal abnormality overwrite permission area. It is possible to store the abnormality analysis data at the time of abnormality detection by the initial diagnosis at the start of operation of the steering assist control mechanism and the abnormality analysis data at the time of abnormality detection by the continuous diagnosis after the operation start, The effect that the abnormality analysis at the time of abnormality occurrence can be performed accurately is obtained.

Furthermore, according to the invention according to claim 2 , since abnormality analysis data for a predetermined time before and after an abnormality is detected by the abnormality data storage means is held in time series, the process leading to the abnormality and the subsequent state Can be accurately determined from the time-series data.
Furthermore, according to the invention of claim 3 , the time-series data of the detection period within the first predetermined time leading to the occurrence of abnormality as the time-series data and the time of the confirmation period from the detection period to the second predetermined time Since it is composed of series data, there is an effect that it is possible to reliably analyze data changes in the process of detecting anomalies.

Still further, in the invention according to claim 4 , the initial abnormality detection means detects the initial abnormality of the torque detection means included in the steering assist control mechanism and the control means included in the steering assist control mechanism as an initial abnormality detection mode. Initial abnormality detection, detection of initial abnormality of current detecting means included in the steering assist control mechanism, detection of initial abnormality of electric motor included in the steering assist control mechanism, detection of initial abnormality of power supply system, and detection of initial abnormality of the storage device Since any one or more are performed, the effect that the abnormality which arises at the time of an operation start to a steering auxiliary control mechanism can be detected correctly is acquired.

According to the fifth aspect of the present invention, as the normal abnormality detection means, the normal abnormality detection means detects the normal abnormality of the torque detection means included in the steering auxiliary control mechanism, and the steering auxiliary control. Included in the steering assist control mechanism, detection of constant abnormality of the control means included in the mechanism, detection of constant abnormality of the current detection means included in the steering assist control mechanism, detection of constant abnormality of the electric motor included in the steering assist control mechanism, Since any one or more of the normal abnormality detection of the vehicle speed detection means and the normal abnormality detection of the power supply system are performed, there is an effect that the abnormality that occurs after the steering auxiliary control mechanism starts operating can be accurately detected. can get.

Further, according to the invention of claim 6 , the data amount of the abnormality analysis data stored in the initial and always overwrite prohibition storage area is managed by the data amount management means, and the data amount of the abnormality analysis data is small. When abnormality analysis data occurs, new abnormality analysis data is additionally stored when this abnormality analysis data can be stored in the overwrite-protected area, so the storage capacity of the initial and permanent overwrite-protected storage areas is effective. The effect that it can be utilized is acquired.
Furthermore, according to the invention of claim 7 , since the data amount managing means stores and manages the data amount stored in the initial abnormality and always abnormal overwrite prohibition storage area in the nonvolatile memory, the data amount Data management can be performed without loss of data.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention. In the figure, 1 is a steering wheel, and a steering force applied to the steering wheel 1 from a driver is an input shaft 2a and an output shaft. And 2b to the steering shaft 2. The steering shaft 2 has one end of the input shaft 2a connected to the steering wheel 1 and the other end connected to one end of the output shaft 2b via a steering torque sensor 3 as steering torque detecting means. Here, the steering torque sensor 3 monitors whether the sensor voltage supplied to the main torque sensor 3m, the sub torque sensor 3s, and the torque sensors 3m and 3s is normal, and the sensor voltage is abnormal. The sensor voltage monitoring unit 3w outputs a voltage abnormality detection signal SA having a logical value “1”.

  The steering force transmitted to the output shaft 2 b is transmitted to the lower shaft 5 via the universal joint 4 and further transmitted to the pinion shaft 7 via the universal joint 6. The steering force transmitted to the pinion shaft 7 is transmitted to the tie rod 9 via the steering gear 8 and steers steered wheels (not shown). Here, the steering gear 8 is configured in a rack and pinion type having a pinion 8a connected to the pinion shaft 7 and a rack 8b meshing with the pinion 8a, and the rotational motion transmitted to the pinion 8a is linearly moved by the rack 8b. It has been converted to movement.

A steering assist mechanism 10 for transmitting a steering assist force to the output shaft 2b is connected to the output shaft 2b of the steering shaft 2. The steering assist mechanism 10 includes a reduction gear 11 connected to the output shaft 2 b and an electric motor 13 as an electric motor that generates a steering assist force connected to the reduction gear 11.
The steering torque sensor 3 detects the steering torque applied to the steering wheel 1 and transmitted to the input shaft 2a. For example, the steering torque sensor 3 is a torsion bar (not shown) in which the steering torque is interposed between the input shaft 2a and the output shaft 2b. It is configured to convert to a torsional angular displacement and detect the torsional angular displacement with a potentiometer. The torque sensor 3, as shown in FIG. 2, when the steering torque input is zero, a predetermined neutral voltage V ₀ becomes, when the right turn from this state, the neutral voltage V ₀ in accordance with the increase of the steering torque When the steering torque is turned to the left from a state where the steering torque is zero, a torque detection value T that is a voltage that decreases from the neutral voltage V _{0 as the} steering torque increases is output.

The torque detection values Tm and Ts output from the torque sensor 3 are input to the control device 14. The controller 14 is supplied with power from the battery 15 via the key switch 16, and in addition to the torque detection values Tm and Ts, the vehicle speed detection value V detected by the vehicle speed sensor 17 and the drive that flows through the electric motor 13. A current detection value I _{MD is} also input, a steering assist command value I _M ^* for generating a steering assist force in the electric motor 13 according to the input torque detection value Tm and the vehicle speed detection value V is calculated, and the calculated steering assist command The drive current supplied to the electric motor 13 is feedback-controlled by the value I _M ^* and the motor current detection value I _MD .

As shown in FIG. 3, the control device 14 performs a predetermined calculation based on the torque detection values Tm and Ts and the vehicle speed detection value V, and outputs a motor drive signal Ir and a motor direction signal Ds ( (Micro Controller Unit) 101 and 102, a motor drive circuit 110 for driving the electric motor 13 based on the motor drive signal Ir and the motor direction signal Ds output from the main MCU 101, and the motor drive circuit 110 connected to the key switch 16. a relay 111 for controlling the power supply to a motor current detection circuit 112 for detecting a motor current I _MD, based from the motor current I _MD and the motor drive circuit 18 to the motor terminal voltage V _M supplied to the electric motor 13 A motor angular speed estimation circuit 113 for estimating the motor angular speed ω, and the main MCU 101 And a temperature sensor 114 for detecting the temperature in the vicinity of the fine sub MCU 102.

  The main MCU 101 includes a self-monitoring watchdog timer (WDT) 101m and a sub watchdog timer (WDT) 101s for mutual monitoring, and the sub MCU102 also performs self-monitoring watch. A dog timer (WDT) 102s and a main watch dog timer (WDT) 102m are provided. Then, the sub MCU 102 determines that the main CPU 101 is abnormal due to program runaway or the like when the main watchdog timer 102m is up, and outputs a motor drive inhibition signal Mp to the motor drive circuit 110 to drive the motor 13. And an off signal is output to the relay 111.

Both the main MCU 101 and the sub MCU 102 generate motor drive signals I _MM and I _MS based on the torque detection values Tm and Ts, the vehicle speed detection value V, the current detection value I _MD , and the motor angular velocity ω. only the drive signal I _MM is input to the motor driving circuit 110, the motor drive signal I _MS calculated in sub MCU102 is used for monitoring. Therefore, the sub MCU 102, determines that the time deviation between compares the motor driving signal I _MM to the motor drive signal I _MS and main MCU101 itself are calculated is calculated is within a predetermined range main MCU101 is normal However, when the deviation is out of the predetermined range, the main MCU 101 is determined to be abnormal, and the motor drive inhibition signal Mp is output to the motor drive circuit 110 and the off signal is output to the relay 111.

Here, as shown in FIG. 3, the main MCU 101 includes a ROM (Read Only Memory) 130 for storing a steering assist control processing program, an abnormality detection processing program, etc. executed by both MCUs, a torque detection value T, and a motor current. Built-in RAM (Random Access Memory) 131 for storing detection data such as detection value _IMD and motor angular velocity ω, data necessary for steering assist control processing and abnormality detection processing executed by MCU, and processing results In addition, at least an electrically erasable EEPROM 132 that stores abnormality analysis data when an abnormality is detected in the steering assist mechanism is incorporated, and an alarm device 133 that issues an alarm is connected. In addition, the sub MCU 102 includes at least a ROM 130 for storing a steering assist control processing program and the like, and a RAM 131 for storing data and processing results required in a process such as a steering assist control process executed by the MCU.

Here, as shown in FIG. 4, the EEPROM 132 starts the abnormality detection process at the time of shipment from the factory and then starts the initial abnormality detection process at the start of the operation of the steering auxiliary control device and the operation after the operation of the steering auxiliary control device is started. Overwrite prohibition storage area MA1 for storing abnormality analysis data (vehicle speed detection value V, steering torque detection value T, motor current detection value I _MD ) first generated in the normal abnormality detection process as initial abnormality analysis data and normal abnormality analysis data Overwrite-prohibiting EEPROMs 132a1 and 132b1 in which MB1 is formed and overwrite-permitted EEPROMs 132a2 and 132b2 in which overwrite-permitted storage areas MA2 and MB2 for storing the second and subsequent initial abnormality analysis data and constant abnormality analysis data are formed. .

Further, as shown in FIG. 5, the steering assist control process executed by the main MCU 101 and the sub MCU 102 first reads the torque detection value Tm detected by the main torque sensor 3m of the steering torque sensor 3 in step S1, and then performs step In S2, the neutral torque V ₀ is subtracted from the detected torque value Tm to calculate the steering torque Tr (= T−V ₀ ). Next, the process proceeds to step S3, where the vehicle speed detection value V detected by the vehicle speed sensor 17 is read, and then the process proceeds to step S4, where the steering assist command value calculation shown in FIG. 6 is performed based on the steering torque Tr and the vehicle speed detection value V. With reference to the map, a steering assist command value I _M ^* which is a motor current command value is calculated.

Here, as shown in FIG. 6, the steering assist command value calculation map has the steering torque detection value T on the horizontal axis, the steering assist command value I _M ^* on the vertical axis, and the vehicle speed detection value V as a parameter. A straight line portion L1 that is configured by a characteristic diagram and extends with a relatively gentle gradient regardless of the vehicle speed detection value V until the steering torque Ts increases in the positive direction from “0” and reaches the first set value Ts1. When the steering torque Ta increases from the first set value Ts1, the straight line portions L2 and L3 that extend with a relatively gentle gradient and the steering torque detection value Ts become the first when the vehicle speed detection value V is relatively fast. Straight line portions L4 and L5 that are parallel to the horizontal axis in the vicinity of the second set value Ts2 that is greater than the set value Ts1 of 1, and in a state where the vehicle speed detection value V is slow, the straight line portions L6 and L7 having a relatively large gradient, A straight line with a larger gradient than these straight line portions L6 and L7. Four characteristic lines formed by the portions L8 and L9, the straight portion L10 having a larger gradient than the straight portion L8, and the straight portions L11 and L12 extending in parallel with the horizontal axis from the ends of the straight portions L9 and L10 are formed. Similarly, when the steering torque Ts increases in the negative direction, there are four characteristic lines that are point targets with the above and the origin in between.

Next, the processing proceeds to step S5, reads the motor acceleration omega estimated by the motor angular velocity estimation circuit 20, and then proceeds to step S6, by multiplying the inertia gain K _i to the motor angular velocity omega, is the motor inertia acceleration The inertia compensation value I _i (= K _i · ω) for inertia compensation control for obtaining the steering sensation without inertia is calculated by removing the torque from the steering torque Tr, and the absolute value of the steering assist command value I _M ^* is calculated. Friction compensation value I _f (= K _f · I _M ^* ) for friction compensation control in order to eliminate the influence of the friction of the power transmission unit and the electric motor on the steering force by multiplying the value by the friction coefficient gain K _f Is calculated. Here, the sign of the friction compensation value _If is determined on the basis of the sign of the steering torque Tr and the steering direction signal for determining whether the steering is increased / returned based on the steering torque Tr.

Next, the process proceeds to step S7, the steering torque Tr is subjected to differential calculation processing to calculate the center response improvement command value Ir for ensuring stability in the assist characteristic dead zone and compensating for static friction, and the process proceeds to step S8. The calculated inertia compensation value I _i , friction compensation value _If and center response improvement command value Ir are added to the steering assist command value I _M ^* to obtain the steering assist compensation value I _M ^* ′ (= I _M ^* + I _i + I _f + Ir) is calculated, and then the process proceeds to step S9 to differentiate the steering assist compensation value I _M ^* ′ to calculate a differential value Id for feedforward control.

Next, the process proceeds to step S10, the motor current detection value _IMD is read, and then the process proceeds to step S11, where the current deviation ΔI is calculated by subtracting the motor current detection value _IMD from the steering assist compensation value I _M ^* ′. Then, the process proceeds to step S12, where the current deviation ΔI is proportionally calculated to calculate a proportional value ΔIp for proportional compensation control, and then the process proceeds to step S13, where the current deviation ΔI is integrated and processed to integrate compensation. An integral value ΔIi for control is calculated, and then the process proceeds to step S14, and the motor drive current I _Mj (j = M, S) (= Id + ΔIp + ΔIi) is obtained by adding the differential value Id, the proportional value ΔIp, and the integral value ΔIi. Is calculated, and then the process proceeds to step S15.
In step S15, the motor drive current I _M calculated in step S14 is output to the motor drive circuit 18, and the process returns to step S1.

  Further, the main MCU 101 executes an abnormality detection process for detecting an abnormality of the steering assist control mechanism shown in FIG. This abnormality detection process is started, for example, when the key switch 16 is turned on and the control device 14 is turned on. First, in step S31, it is determined whether an ignition switch (not shown) is on. When it is in an off state, it is determined that the steering assist control device is in an inoperative state and waits until the ignition switch is in an on state. When the ignition switch is in an on state, the process proceeds to step S32. After the initial abnormality detection process shown in FIG. 8 is started, the process proceeds to step S33.

In step S33, it is determined whether or not the initial abnormality detection process has been completed. If the initial abnormality detection process has not been completed, the process waits until the initial abnormality detection process has been completed, and the process proceeds to step S34 when the initial abnormality detection process has been completed.
In step S34, the normal abnormality detection process shown in FIG. 10 is started, and then the process proceeds to step S35 to determine whether or not the ignition switch is turned off. When the ignition switch is kept on, The system waits until it is turned off. When the ignition switch is turned off, the process proceeds to step S36, where the normal abnormality detection process is stopped and then the process returns to step S31.

The initial abnormality detection process is executed as a timer interruption process for a predetermined time, for example, every 2 ms, for a predetermined main program. As shown in FIG. 8, first, in step S41, the RAM 131 is verified for writing and reading. To determine whether or not the RAM 131 is normal. If the RAM 131 is abnormal, the process proceeds to step S42, and the first overwriting prohibition storage area MA1 of the overwriting prohibiting EEPROM 132a1 is determined. The initial data discrimination flag FTA stored in the normal ROM of the EEPROMs 132a1 and 132b2 indicating whether or not the initial abnormality analysis data is stored is set to “1” indicating that the first initial abnormality analysis data is stored. The initial data discrimination flag FTA is reset to “0”. If it is determined that the initial initial abnormality analysis data is not stored in the overwrite storage area MA1, the process proceeds to step S43.

In step S43, a RAM abnormality command indicating that the RAM 131 is abnormal is written to the overwrite prohibition storage area MA1, and then the process proceeds to step S44, where the initial data determination flag FTA stored in the normal ROM of the EEPROMs 132a1 and 132b2 is stored. Is set to “1” and then the process proceeds to step 45 to determine whether or not the preset initial abnormality detection processing time has elapsed. If the initial abnormality detection processing time has not elapsed, the timer interrupt processing is performed. When the initial abnormality detection processing time has elapsed, the initial abnormality detection process is terminated.
If the initial data determination flag FTA is set to “1” as a result of determination in step S42, the process proceeds to step S46, and a RAM abnormality command indicating that the RAM 131 is abnormal is formed in the overwrite-allowing EEPROM 132a2. After storing the data in the overwritable storage area MA2, the process proceeds to step S45.

  On the other hand, when the determination result of step S41 is normal, the RAM 131 is normal, the process proceeds to step S47, the sum of the EEPROMs 132a1 to 132b2 is checked, and it is detected whether or not the EEPROMs 132a1 to 132b2 are inconsistent. If any of the EEPROMs 132a1 to 132b2 is abnormal, the process proceeds to step S48 to determine whether or not the initial data determination flag FTA is set to “1”. When it is set to "", the process proceeds to step S49 to determine whether or not the abnormal EEPROM is the initial abnormal overwriting prohibition EEPROM 132a1, and when the initial abnormal overwriting prohibition EEPROM 132a1 is normal, the step S50 is performed. E that became abnormal An EEPROM abnormality command indicating that one of the EPROMs 132a2, 132b1 and 132b2 is abnormal is stored in the initial abnormality overwriting prohibition EEPROM 132a1, and then the process proceeds to step S51 where the initial data determination flag FTA is set to "1". When the initial abnormal overwriting prohibition EEPROM 132a1 is abnormal, the process proceeds to step S52, and an EEPROM abnormal command indicating that the initial abnormal overwriting prohibition EEPROM 132a1 is abnormal is sent to the initial abnormal overwriting permission EEPROM 132a2. After storing, the process proceeds to step S53, and after outputting an abnormal alarm signal to the alarm circuit 133, the process proceeds to step S45.

  If the initial data determination flag FTA is set to “1” as a result of determination in step S48, the process proceeds to step S54 to determine whether or not the abnormal EEPROM is the initial abnormal overwriting allowance EEPROM 132a2. If it is determined that the EEPROM is not the initial abnormality overwriting allowance EEPROM 132a2, the process proceeds to step S55, and the EEPROM abnormality command indicating the abnormal EEPROM is stored in the initial abnormality overwriting allowance EEPROM 132a2, and then the process proceeds to step S45. When the overwriting-permitted EEPROM 132a2 is abnormal, the process proceeds to step S56, and an EEPROM abnormality command indicating an abnormality of the initial abnormal overwriting-permitted EEPROM 132 is stored in the always-abnormal overwriting-permitted EEPROM 132b2, and then step S5. Proceeds to transitions from outputs an abnormality warning signal to the alarm circuit 133 to the step S45.

  On the other hand, if the determination result in step S47 is normal for the EEPROMs 132a1 to 132b1, the process proceeds to step S58 to determine whether the self-watchdog timer 101m has timed up without generating a clear command within a predetermined time. It is determined whether or not the main MCU 101 is normal. If the main MCU 101 is abnormal, the process proceeds to step S59, and the same processes as those in steps S42 to S44 and S46 described above are performed, Depending on the state of the data discrimination flag FTA, an abnormal storage process for storing a main MCU abnormality command indicating that the main MCU 101 is abnormal is executed in the initial overwriting prohibition EEPROM 132a1 or the initial overwriting permission EEPROM 132a2, and then the process proceeds to step S45. To do.

  If the result of the determination in step S58 is that the main MCU 101 is normal, the process proceeds to step S60, and whether or not the sub watchdog timer 101s has timed up without generating a clear command in the sub MCU 102 within a predetermined time. It is determined whether or not the sub MCU 102 is normal. If the sub MCU 102 is abnormal, the process proceeds to step S61, and the same processes as those in steps S42 to S44 and S46 described above are performed. After executing the abnormal storage process for storing the sub MCU abnormal command indicating that the sub MCU 102 is abnormal in the initial overwriting prohibition EEPROM 132a1 or the initial overwriting permission EEPROM 132a2 in accordance with the state of the initial data determination flag FTA, step S45 is performed. Migrate to

  Furthermore, when the determination result of step S60 is that the sub MCU 102 is normal, the process proceeds to step S62, and whether or not the MCU vicinity temperature detected by the temperature sensor 114 is normal within a preset normal temperature range. If the temperature near the MCU is outside the normal temperature range, the process proceeds to step S63, and the same processes as the processes of steps S42 to S44 and S46 described above are performed, according to the state of the initial data determination flag FTA. After executing the abnormal storage process for storing the temperature detected by the temperature sensor 114 in the initial overwriting prohibition EEPROM 132a1 or the initial overwriting permission EEPROM 132a2, the process proceeds to step S45.

Furthermore, when the determination result of the step S62 is normal when the temperature near the MCU is within the normal temperature range, the process proceeds to step S64, where the torque detection values Tm and Ts of the main torque sensor 3m and the sub torque sensor 3s are detected. After reading the voltage abnormality detection signal SA output from the sensor voltage monitoring unit 3w, the process proceeds to step S65.
In step S65, the torque deviation ΔT is calculated by performing the calculation of the following equation (1) based on the detected torque values Tm and Ts.
ΔT = | Tm−Ts | (1)

  Next, the process proceeds to step S66, where it is determined whether or not the calculated torque deviation ΔT is a normal state that is equal to or smaller than a preset set value ΔTs. If ΔT ≦ ΔTs and the normal state is satisfied, the process proceeds to step S67. Then, a torque abnormality detection flag FT, which will be described later, is reset to “0”, and then the process proceeds to step S68 to erase the time series data stored in the RAM 131, and then the process proceeds to step S70 described later, and ΔT> When ΔTs is in an abnormal state, the process proceeds to step S69, and after performing the torque sensor abnormality detection storage process shown in FIG. 9 for detecting the abnormality of the torque sensor 3 by setting the set detection period and fixed period. Control goes to step S45.

  In step S70, the voltage abnormality detection signal SA input from the torque sensor power supply monitoring unit 3w is read to determine whether or not the voltage abnormality detection signal SA is a logical value “0”, and the voltage abnormality detection signal SA is a logical value “1”. If "", the process proceeds to step S71, and the same processes as the processes of steps S42 to S44 and S46 described above are performed, and the initial overwrite prohibition EEPROM 132a1 or the initial overwrite permission EEPROM 132a2 depending on the state of the initial data determination flag FTA. After executing an abnormality storage process for storing a torque sensor power supply abnormality command indicating that the torque sensor power supply is abnormal, the process proceeds to step S45.

  Furthermore, when the determination result of step S70 indicates that the torque sensor power supply is normal, the process proceeds to step S72, where the state in which the battery voltage Vb is outside the preset normal voltage range has not been continued for a predetermined time. When the battery voltage Vb is out of the normal voltage range, the same processing as the processing of steps S42 to S44 and S46 described above is performed, and initial overwriting prohibition is performed according to the state of the initial data determination flag FTA. After executing the abnormal storage process for storing the battery voltage Vb in the EEPROM 132a1 or the initial overwriting permission EEPROM 132a2, the process proceeds to step S45.

  In the torque sensor abnormality detection storage process in step S69, as shown in FIG. 9, first, in step S691, it is determined whether or not the torque abnormality detection flag FT is reset to “0”. When the period is reset to step S692, the detection period continuation count value N1 is cleared to "0", and the period state flag FS indicating that the period is in the detection period or the determination period is set in the detection period. The process proceeds to step S693 after resetting to "0", and the torque abnormality detecting flag FT is set to "1", and then the process proceeds to step S45.

On the other hand, if the determination result in step S691 is that the torque abnormality detection flag FT is set to “1”, the process proceeds to step S694 to determine whether or not the period state flag FS is set to “1”. When this is reset to “0”, it is determined that it is in the detection period, and the process proceeds to step S695.
In this step S695, "1" is incremented to the current detection period continuation count value N1 to calculate a new detection period continuation count value N1, and then the process proceeds to step S696, where the detection period continuation count value N1 is the detection period. It is determined whether or not the set value N1s representing the end has been reached. If N1 <N1s, it is determined that the detection period is in progress, and the process proceeds to step S697, where the main torque detection value Tm, the sub torque detection value Ts, migrating motor current detection value I _MD and the vehicle speed detection value V from the temporarily stored in the RAM131 as time-series data in the step S45.

When the determination result in step S696 is N1 ≧ N1s, it is detected that the torque sensor 3 is abnormal because the end of the detection period is reached, the process proceeds to step S698, and the period state flag FS is set to “1”. Then, the process proceeds to step S699, and after the confirmation period continuation count value N2 is cleared to “0”, the process proceeds to step S697.
On the other hand, when the determination result of step S684 is that the period state flag FS is set to “1”, the process proceeds to step S700, and “1” is incremented to the current fixed period continuation count value N2. After calculating a new fixed period continuation count value N2, the process proceeds to step S701.

  In this step S701, it is determined whether or not the fixed period continuation count value N2 calculated in step S700 has reached a set value N2s representing the end of the fixed period. If N2 <N2s, the fixed period has not ended. The process proceeds to step S697, and when N2 ≧ N2s, it is determined that the determination period has ended and the abnormality of the torque sensor 3 has been determined, the process proceeds to step S702, and the overwrite prohibition memory of the overwrite prohibition EEPROM 132a1 is determined. It is determined whether or not the initial data determination flag FTA indicating whether or not the first initial abnormality analysis data is stored in the area MA1 is set to “1” indicating that the first initial abnormality analysis data is stored. When the initial data discriminating flag FTA is reset to “0”, the initial initial discrepancy is stored in the overwrite storage area MA1. It is determined that the normal analysis data is not stored, and the process proceeds to step S703.

  In this step S703, the time series data of the main torque detection value Tm and the sub torque detection value Ts stored in the RAM 131 is written into the overwrite prohibition storage area MA1, and then the process proceeds to step S704, where the time series data stored in the RAM 131 is stored. Then, the process proceeds to step S705, the initial data determination flag FTA is set to "1", and then the process proceeds to step S45.

  When the initial data determination flag FTA is set to “1” as a result of determination in step S702, the process proceeds to step S706, where the main torque detection value Tm and the sub torque detection value Ts stored in the RAM 131 are set. After the time series data is stored in the overwrite-allowable storage area MA2 formed in the overwrite-allowable EEPROM 132a2, the process proceeds to step S707, and the time-series data stored in the RAM 131 is erased, and then the process proceeds to step S45.

  Also, in the abnormality detection storage process of step S73 of FIG. 8, the battery voltage Vb is processed in the same manner as the above steps S691 to S707, and the battery voltage Vb is stored in the RAM 131 in the detection period and the determination period. When the voltage abnormality is determined, the time series data of the battery voltage stored in the RAM 131 is stored in the overwrite prohibition EEPROM 132a1 or the overwrite permission EEPROM 132a2 according to the state of the initial data determination flag FTA.

  As shown in FIG. 10, in the normal abnormality detection process, first, in step S81, verification of writing and reading is performed at the time of writing to the EEPROMs 132a1 to 132b2, and it is detected whether or not both are normal. Thus, it is determined whether or not the EEPROMs 132a1 to 132b2 are normal. If any of the EEPROMs 132a1 to 132b2 is abnormal, the process proceeds to step S82, and whether or not the initial data determination flag FTB is set to “1”. When this is set to "0", the process proceeds to step S83, where it is determined whether the abnormal EEPROM is the always abnormal overwrite prohibiting EEPROM 132b1, and the always abnormal overwrite prohibiting EEPROM 132b1 is If it is normal, the process proceeds to step S85, where the abnormality The EEPROM abnormal command indicating that one of the EEPROMs 132a2, 132b1 and 132b2 is abnormal is stored in the abnormal overwriting prohibiting EEPROM 132b1, and then the process proceeds to step S85, and the initial data determination flag FTB is set to "1". After setting, the timer interrupt process is terminated and the program returns to the predetermined main program. When the abnormal overwriting prohibition EEPROM 132b1 is abnormal, the process proceeds to step S86, and the normal abnormal overwriting allowance EEPROM 132b2 is always used for prohibiting abnormal overwriting. After storing the EEPROM abnormality command indicating that the EEPROM 132b1 is abnormal, the process proceeds to step S87, the abnormality alarm signal is output to the alarm circuit 133, the timer interruption process is terminated, and the process returns to the predetermined main program. .

  If the initial data determination flag FTB is set to "1" as a result of determination in step S82, the process proceeds to step S88, and it is determined whether or not the abnormal EEPROM is always an abnormal overwriting allowance EEPROM 132b2. If it is determined that the EEPROM is not always overwritable overwriting EEPROM 132b2, the process proceeds to step S89, an EEPROM overwhelming command indicating the abnormal EEPROM is stored in the overwhelming overwriting overwhelming EEPROM 132b2, and the timer interrupt process is terminated and predetermined. When the normal overwriting allowance EEPROM 132b2 is abnormal, the process proceeds to step S90, and the initial abnormal overwriting allowance EEPROM 132a2 is transferred to the initial abnormal overwriting allowance EEPROM 132b2. Shifts from stores command in step S91, the From and outputs an abnormality warning signal to the alarm circuit 133 to end the timer interrupt processing returns to the predetermined main program.

  On the other hand, if the determination result in step S81 is that the EEPROMs 132a1 to 132b1 are normal, the process proceeds to step S92 to determine whether or not the self watchdog timer 101m has timed out without generating a clear command within a predetermined time. It is determined whether or not the main MCU 101 is normal. If the main MCU 101 is abnormal, the process proceeds to step S93, and the processes of steps S42 to S44 and S46 in the initial abnormality detection process shown in FIG. The abnormality storage process for storing the main MCU abnormality command indicating that the main MCU 101 is abnormal in the always overwriting prohibiting EEPROM 132b1 or the always overwriting permissible EEPROM 132b2 according to the state of the initial data determination flag FTB is performed. Do you run To end the timer interrupt processing returns to the predetermined main program.

  If the result of determination in step S92 is that the main MCU 101 is normal, the process proceeds to step S94, and whether or not the sub watchdog timer 101s has timed up without generating a clear command in the sub MCU 102 within a predetermined time. Whether or not the sub MCU 102 is normal is determined. When the sub MCU 102 is abnormal, the process proceeds to step S103, and the same process as the process of steps S42 to S44 and S46 of FIG. After executing the abnormal storage processing for storing the sub MCU abnormality command indicating that the sub MCU 102 is abnormal in the always overwriting prohibition EEPROM 132b1 or the always overwriting permissible EEPROM 132b2 according to the state of the initial data determination flag FTB. End timer interrupt processing To return to the main program.

Further, when the determination result of step S94 is that the sub MCU 102 is normal, the process proceeds to step S96, where it is determined whether or not the steering assist compensation value I _M ^* ′ calculated by the main MCU 101 and the sub MCU 102 substantially matches. Then, it is determined whether or not the command value calculation of both MCUs 101 and 102 is normal. When the steering assist compensation value I _M ^* ′ of the both is different by a predetermined value or more, it is determined that the command value calculation of the main MCU 101 is abnormal. Then, the process proceeds to step S97, and the same processes as the processes of steps S42 to S44 and S46 of FIG. 8 described above are performed, and the always overwrite prohibiting EEPROM 132b1 or the always overwrite permitting EEPROM 132b2 depending on the state of the initial data discrimination flag FTB. The main MCU command value calculation indicating that the command value calculation of the main MCU 101 is abnormal After executing the abnormal storage process for storing the abnormal command, the timer interrupt process is terminated and the process returns to the predetermined main program.

Furthermore, the determination of the step S96 is, when the command value computation is normal, the process proceeds to step S98, whether the motor current I _MD detected by the motor current detecting circuit 112 is not continued for the predetermined time period a predetermined abnormalities by detecting whether the motor current I _MD is equal to or normal, when the motor current I _MD is overcurrent abnormality proceeds to step S99, steps S42~S44 and of FIG. 8 described above performing S46 in the process and the same processing, the abnormality storage process of storing the value of the motor current I _MD, which becomes abnormal always overwrite prohibition EEPROM132b1 or constantly overwrite allowable for EEPROM132b2 in accordance with the state of the initial data discriminating flag FTB After execution, the timer interrupt process is terminated and the process returns to a predetermined main program.

Furthermore, when the determination result in step S98 is that the motor current _IMD is normal, the process proceeds to step S100, where the drive power of the motor drive circuit 110 is abnormal, the motor neutral point is abnormal, the position signal detection power is abnormal, the position It is determined whether or not the motor control system in which the detection Hall IC abnormality or the like has not occurred is normal. If an abnormality has occurred in the motor control system, the process proceeds to step S101, and the above-described FIG. The processing similar to the processing in steps S42 to S44 and S46 is performed, and an abnormal command indicating the cause of the abnormality is stored in the constantly overwriting prohibiting EEPROM 132b1 or the constantly overwriting permitting EEPROM 132b2 according to the state of the initial data determination flag FTB. After executing the storage process, the timer interrupt process is terminated and the process returns to a predetermined main program.

  Still further, if the determination result in step S100 is normal, the control proceeds to step S102, and whether or not the temperature near the MCU detected by the temperature sensor 114 is normal within a preset normal temperature range. When the temperature near the MCU is outside the normal temperature range, the process proceeds to step S103, and the same processes as the processes of steps S42 to S44 and S46 of FIG. 8 described above are performed, and the state of the initial data determination flag FTB is determined. In response to this, an abnormal storage process for storing the temperature detected by the temperature sensor 114 is executed in the always overwrite prohibiting EEPROM 132b1 or the always overwrite permitting EEPROM 132b2, and then the timer interrupt process is terminated to return to a predetermined main program.

On the other hand, if the determination result of 102 is normal when the temperature near the MCU is within the normal temperature range, the process proceeds to step S104, and the torque detection values Tm and Ts of the main torque sensor 3m and the sub torque sensor 3s and the sensor voltage are transferred. After reading the voltage abnormality detection signal SA output from the monitoring unit 3w, the process proceeds to step S105.
In this step S105, it is determined whether or not the main torque detection value Tm detected by the main torque sensor 3m is within the normal range of the preset upper limit value Tmsu to the lower limit value Tmsl. In S106, the detection period and the confirmation period are set, and the main torque detection value Tm is stored as time-series data in the RAM 131 as in the abnormality detection storage process of FIG. After replacing the FT with a torque abnormality detection flag FTm and performing the abnormality detection storing process with the initial data determination flag FTA replaced with the initial data determination flag FTB, the timer interruption process is terminated and the process returns to the main program.

Further, when the determination result of step S105 is that the main torque sensor 3m is normal, the process proceeds to step S107, the torque abnormality detecting flag FTm is reset to “0”, then the process proceeds to step S108, and the RAM 131 is stored. After erasing the stored time series data, the process proceeds to step S109.
In this step S109, it is determined whether or not the main torque detection value Ts detected by the sub torque sensor 3s is within a normal range of the preset upper limit value Tssu to the lower limit value Tssl. In S110, similarly to the above-described abnormality detection storage process of FIG. 9, the detection period and the confirmation period are set, the sub torque detection value Ts is stored in the RAM 131 as time series data, and the torque abnormality detection flag FT is further stored. Is replaced with the torque abnormality detection flag FTs, and the abnormality detection storage process is performed in which the initial data determination flag FTA is replaced with the initial data determination flag FTB, and then the timer interruption process is terminated and the process returns to the main program.

If the result of determination in step S109 is that the sub torque sensor 3s is normal, the process proceeds to step S111, the torque abnormality detection flag FTs is reset to “0”, then the process proceeds to step S112, and the RAM 131 is stored. After erasing the stored time series data, the process proceeds to step S113.
In this step S113, the torque deviation ΔT is calculated by performing the calculation of the equation (1) based on the torque detection values Tm and Ts, and then the process proceeds to step S114, where the calculated torque deviation ΔT is a preset set value. It is determined whether or not the normal state is equal to or less than ΔTs. When ΔT> ΔTs and the abnormal state is detected, the process proceeds to step S115, and the detection period and the determination period are the same as those in the abnormality detection storage process of FIG. Is set, the initial data determination flag FTA is replaced with the initial data determination flag FTB, the torque sensor abnormality detection storage process is performed, the timer interrupt process is terminated, and the process returns to the predetermined main program. ΔT ≦ ΔTs When it is normal, the routine proceeds to step S116, where the torque abnormality detecting flag FT is reset to “0”, and then step S1. The process proceeds to 17 to erase the time series data stored in the RAM 131, and then the process proceeds to step S118 described later.

  In step S118, the voltage abnormality detection signal SA input from the torque sensor power supply monitoring unit 3w is read to determine whether or not the voltage abnormality detection signal SA is a logical value “0”, and the voltage abnormality detection signal SA is a logical value. When it is 1 ″, the process proceeds to step S119, and the same processing as the processing of steps S42 to S44 and S46 of FIG. 8 described above is performed, and the EEPROM 132b1 for always overwriting prohibition or the constant data depending on the state of the initial data discrimination flag FTB After executing an abnormal storage process for storing a torque sensor power supply abnormality command indicating that the torque sensor power supply is abnormal in the overwriting-permitted EEPROM 132b2, the timer interruption process is terminated and the process returns to a predetermined main program.

  Furthermore, when the determination result of step S118 indicates that the torque sensor power supply is normal, the process proceeds to step S120, where it is normal whether the battery voltage Vb has not continued outside the preset normal voltage range for a predetermined time. When the battery voltage Vb is abnormal, the same processing as the processing of steps S42 to S44 and S46 of FIG. 8 described above is performed, and the overwriting prohibiting EEPROM 132b1 or the constantly overwriting prohibiting EEPROM 132b1 or After executing the abnormal storage process for storing the battery voltage Vb in the always overwritable EEPROM 132b2, the timer interrupt process is terminated and the process returns to a predetermined main program.

Furthermore, when the determination result of step S120 is that the battery voltage Vb is normal, the process proceeds to step S122, and whether or not the vehicle speed sensor 17 is normal depending on whether or not a vehicle speed abnormality signal is input from the vehicle speed sensor 17. When the vehicle speed sensor 17 is abnormal, the process proceeds to step S123, and processing similar to that in steps S691 to S699 in FIG. 9 is performed in which the sampling period is set to 100 ms, the detection period is set to 60 sec, and the determination period is omitted. After performing the abnormality detection storage process, the timer interrupt process is terminated and the process returns to a predetermined main program.
In the normal abnormality detection process, when the abnormality detection storage process is performed, the main torque detection value Tm, the sub-torque detection value Ts, the motor drive signal I _M , the vehicle speed are used as time series data to facilitate later abnormality analysis. The detected value V is stored as a set.

  5 and 7 to 10, the steering assist control mechanism is configured by the process of FIG. 5 and the steering assist mechanism 10, and S41, S47, S58, S60, S62, S64 to S66, S70, S72, The processes of S81, S92, S94, S96, S98, S100, S102, S104, S105, S109, S112, S114, S118, S120, and S122 correspond to the abnormality detection means, and steps S42 to S44, S48 to S57, S59, S61, S63 to S65, S67 to S69, S71, S73, processing of FIG. 9, S82 to S91, S93, S95, S97, S99, S101, S106 to S108, S110 to S112, S115, S119, S121, S123 Corresponds to the abnormal data storage means.

Next, the operation of the above embodiment will be described.
Now, after the assembly of the control device of the electric power steering device is completed at the manufacturing factory, the initial abnormality overwriting prohibition EEPROM 132a1, the initial abnormality overwriting permission EEPROM 132a2 and the constant abnormality overwriting prohibition EEPROM 132b1 constituting the EEPROM 132 are always abnormal. The overwriting-permitted EEPROM 132b2 is in a clear state in which no abnormality analysis data is recorded, and various flags such as an abnormal state flag AF, initial data determination flags FTA and FTB, a torque abnormality detecting flag FT, a period state flag FS, and the like are set. Both are reset to "0".

  In order to start using the vehicle from this shipping state, by turning on the key switch, the control device 14 is powered on, and the main MCU 101 starts executing the processes of FIGS. 5 and 7 to 9. At the same time, the processing of FIG. At this time, in the main MCU 101, when the ignition switch is turned on, the initial abnormality detection process shown in FIG. 8 is first executed when the power is turned on. The RAM 131, the EEPROMs 132a1, 132a2, and 132b1, 132b2, the main MCU 101, and the sub MCU 102 It is determined whether or not it is normal, and an initial diagnosis is performed as to whether or not the temperature near the MCU is normal and whether or not the torque sensor 3m is normal. When each part is normal in this initial diagnosis, The steering assist control process in FIG. 5 and the constant abnormality detection process in FIG. 10 are executed.

5, the steering torque Ts is calculated by subtracting the neutral voltage V ₀ from the torque detection value T detected by the steering torque sensor 3 (step S2), and then the vehicle speed detection value V is obtained from the vehicle speed sensor 17. Based on the reading (step S3), the steering assist command value I _M ^* is calculated with reference to the steering assist command value calculation map shown in FIG. 6 based on the steering torque Ts and the vehicle speed detection value V (step S4).

On the other hand, the motor angular velocity ω estimated by the motor angular velocity estimation circuit 20 is read (step S5), the inertia compensation value I _i for inertia compensation control is calculated based on the motor angular velocity ω, and the friction compensation value for friction compensation control is calculated. calculating the I _f (step S6), and further the steering torque Ts differential operation to calculate a center response improving command value I _r (step S7), and these inertia compensation value I _i, friction compensation value I _f and the center response The steering assist compensation value I _M ^* ′ is calculated by adding the performance improvement compensation value I _r to the steering assist command value I _M ^* (step S8).

The steering assist compensation value I _M ^* ′ is differentiated to calculate a differential value Id for differential compensation control in feedforward control (step S9), and then the motor current correction value I _MA is subtracted to obtain a current deviation. ΔI is calculated (step S10), the calculated current deviation ΔI is proportionally calculated to calculate a proportional value ΔIp for proportional compensation control, and the integral calculation processing is performed to calculate an integral value ΔIi for integral compensation control ( Next, the differential value Id, the proportional value ΔIp, and the integral value ΔIi are added to calculate the motor drive signal I _M (step S13).

At this time, if no abnormality is detected in the steering assist control system in the abnormality detection process of FIG. 7 and the abnormal state flag AF is reset to “0”, the process proceeds to step S16 and is calculated. By outputting the motor drive signal I _M to the motor drive circuit 110, a drive current is supplied from the motor drive circuit 110 to the electric motor 13, and the steering according to the steering torque applied to the steering wheel 1 by the electric motor 13. An auxiliary force is generated and transmitted to the output shaft 2 b via the reduction gear 11.

At this time, in a so-called stationary state in which the steering wheel 1 is steered while the vehicle is stopped, a large steering angle with a small steering torque Ts is obtained due to the large gradient of the characteristic line of the steering assist command value calculation map shown in FIG. Since the auxiliary command value I _M ^* is calculated, a large steering assist force can be generated by the electric motor 13 to perform light steering. On the other hand, when the vehicle starts and exceeds the predetermined vehicle speed, the gradient of the characteristic line of the steering assist command value calculation map shown in FIG. 6 is reduced, so that a small steering assist command value I _M ^* is calculated even with a large steering torque Ts. Therefore, the steering assist force generated by the electric motor 13 is reduced, and the steering of the steering wheel 1 can be suppressed from becoming too light and optimal steering can be performed.

On the other hand, in the normal abnormality detection process of FIG. 10, it is determined whether or not the EEPROMs 132 a 1 to 132 b 2, the main MCU 101, and the sub MCU 102 are normal by being executed as a timer interrupt process at predetermined time intervals. Whether the command value calculation is normal, whether the motor current I _M is normal, whether the motor control system is normal, whether the temperature near the MCU is normal, the torque sensor 3m is normal It is always determined whether or not the battery voltage Vb is normal and whether or not the vehicle speed sensor 17 is normal.

If no abnormality is detected in the normal abnormality detection process, the steering assist control process in FIG. 5 is continued.
When the steering assist control mechanism is in a normal state, for example, when a short circuit or disconnection occurs in the main torque sensor 3m of the steering torque sensor 3, the detected steering torque value T deviates from the normal range. in shifts from step S105 to step S106, and executes the same processing as FIG. 9, the main torque detection value within the detection period of a predetermined time Tm, the sub torque detection value Ts, the motor current I _M, the vehicle speed V is a predetermined Are stored as time-series data in the RAM 131 at the sampling period, and the main torque detection value Tm, the sub-torque detection value Ts, the motor current I _M , and the vehicle speed V are similarly stored in the RAM 131 at the predetermined sampling period. Stored as series data.

  When the determination period ends, the initial data determination flag FTB is reset to “0” when it is the first abnormality, so that the time series data is always stored in the abnormal overwriting prohibition EEPROM 132b1 as shown in FIG. When the initial abnormality or other abnormality first occurs and the initial data determination flag FTB is set to “1”, the time series data is always stored in the abnormal overwriting allowance EEPROM 132b2.

  Similarly, during execution of the normal abnormality detection process, an abnormality that falls outside the normal range occurs in the sub torque sensor 3s, or an abnormality in which the deviation ΔT between the main torque detection value Tm and the sub torque detection value Ts exceeds the predetermined value ΔTs. 9 is performed, the abnormality detection storing process of FIG. 9 is performed in the same manner as described above, and the time series data of the detection period and the confirmation period is always abnormal overwriting prohibition EEPROM 132b1 or always abnormal overwriting permitted depending on the state of the initial data determination flag FTB. Is stored in the EEPROM 132b2.

On the other hand, if an abnormality occurs in the command value calculation of the main MCU 101, sub MCU 102, main MCU 101, motor current I _M , motor control system, MCU vicinity temperature, or battery voltage Vb during the normal abnormality detection process, the abnormality is detected. At the time of occurrence, an abnormal command indicating an abnormality that has occurred according to the state of the initial data determination flag FTB is stored in the always abnormal overwrite prohibiting EEPROM 132a1 or the always abnormal overwrite allowing EEPROM 132b2.

  As described above, in the always-abnormality detection process, the first abnormality that occurs after shipment is stored in the always-overwrite-inhibiting EEPROM 132b1 as time series data, an abnormality command, or an abnormality detection value, and subsequent overwriting is prohibited. Therefore, the first abnormality that occurs when the steering assist control device is in operation is reliably held, and the abnormality that occurs thereafter is overwritten and stored in the overwriting permission EEPROM 132b2.

Therefore, when performing the analysis of the case where abnormality occurs in the steering assist control, EEPROM132b1 and by reading the abnormality analysis data stored in 132b2, reliably Oh Luke what initial abnormality occurrence While being able to grasp, it is also possible to grasp whether or not other abnormality has occurred although subsequent abnormality is also overwritten and stored.
Similarly, in the initial abnormality detection process of FIG. 8, when an abnormality occurs for the first time, any of time-series data, abnormality command and abnormality detection value is stored in the initial abnormality overwriting prohibition EEPROM 132a1, and the abnormality after the second time is detected. When it occurs, it is overwritten and stored in the initial abnormal overwriting allowance EEPROM 132a2.

Therefore, the abnormality that occurs in the initial state when the power is turned on to the steering control device can be reliably stored in the initial abnormality overwriting prohibition EEPROM 132a1 and the initial abnormality overwriting allowance EEPROM 132a2, and the abnormality analysis can be performed accurately. .
As described above, according to the above-described embodiment, when the abnormality is detected by the two abnormality detection processes of the initial abnormality detection process and the normal abnormality detection process, the time-series data is stored in the individual overwrite prohibiting EEPROMs 132a1, 132a2, and 132b1, 132b2. Since either the abnormality command or the abnormality detection value is stored, it is possible to accurately grasp whether the abnormality of the steering assist control device has occurred in the initial state or the operation state of the steering assist device thereafter, Abnormality analysis can be performed more accurately.

  In addition, when the user detects an abnormality in the steering assist control mechanism and requests a repair from a dealer or the like, the abnormality occurs again when the steering assist control process is started again at the repair destination and the abnormality is confirmed. In addition, the abnormality analysis data collected at this time is overwritten and stored in the overwriting-permitted EEPROM 132a2 or 132b2, and the initial abnormality analysis data stored in the overwriting-prohibiting EEPROMs 132a1 and 132b1 is surely not overwritten. Retained.

  In the above embodiment, the case where the overwrite prohibiting EEPROMs 132a1 and 132b1 and the overwrite permitting EEPROMs 132a2 and 132b2 are provided one by one has been described. However, the present invention is not limited to this. A plurality of 132b2 may be provided, and the number of EEPROMs 132a1, 132a2, 132b1, and 132b2 is not limited to the same number, and any number may be provided individually.

  Furthermore, in the above-described embodiment, the case where the overwrite prohibition EEPROM 132a1 and 132b1 is completely prohibited from being overwritten has been described. However, the present invention is not limited to this, and an abnormal command or abnormality detection value other than time series data is stored. In this case, since these data amounts are small, an overwrite data management unit for storing the data amount to be overwritten in the non-volatile memory is provided, and this overwrite data management unit maximizes the storage amount of the overwrite prohibiting EEPROMs 132a1 and 132b1. It is also possible to continue the memory until.

  That is, as shown in FIG. 11, a data management EEPROM 132c is newly provided in the main MCU 101, and the main MCU 101 performs data writing for managing the amount of data stored in the overwrite prohibition EEPROMs 132a1 and 132b1, as shown in FIG. Execute management processing. This data write management process is executed as a timer interrupt process every predetermined time (for example, 2 msec). First, in step S201, it is determined whether or not data is being written to the overwrite prohibiting EEPROMs 132a1 and 132b1, and overwriting is performed. When the data is not being written to the prohibition EEPROMs 132a1 and 132b1, the timer interrupt process is terminated as it is, and the process returns to a predetermined main program. When the determination result in step S201 is the data write state to the overwrite prohibition EEPROMs 132a1 and 132b1, the process proceeds to step S202 to determine whether or not the write target is the overwrite prohibition EEPROM 132a1. If it is the overwrite prohibiting EEPROM 132a1, the process proceeds to step S203 to determine whether or not the initial data determination flag FTA is “1”. If the initial data determination flag FTA is “0”, the process proceeds to step S204. Then, the data amount Da1 stored in the data amount storage area for the EEPROM 132a1 of the newly provided data management EEPROM is read, then the process proceeds to step S205, and the data amount da to be written to the read data amount Da1. To obtain a new data amount Da1 (= D 1 + da) is calculated.

Next, the process proceeds to step S206, where it is determined whether or not the calculated data amount Da1 has reached the allowable data amount Das of the overwriting prohibition EEPROM 132a1. If Da1 ≦ Das, the process proceeds to step S207 to detect a new abnormality. After the data is written to the overwriting prohibition EEPROM 132a1, the timer interrupt process is terminated and the process returns to a predetermined main program.
On the other hand, when the determination result in step S206 is Da1> Das, the process proceeds to step S208, the initial data determination flag FTA is set to “1”, and then the process proceeds to step S209 for overwriting new abnormal data. After writing to the EEPROM 132a2, the timer interrupt process is terminated and the program returns to a predetermined main program.
If the determination result in step S203 is that the initial data determination flag FTA is “1”, the process directly proceeds to step S209.

  Further, when the determination result in step S202 is that the write target is the overwriting prohibition EEPROM 132b1, the process proceeds to step S210, where it is determined whether or not the initial data determination flag FTB is “1”. When the determination flag FTB is “0”, the process proceeds to step S211, the data amount Db1 stored in the data amount storage area for the EEPROM 132b1 of the newly provided data management EEPROM is read, and then the process proceeds to step S212. The new data amount Db1 (= Db1 + db) is calculated by adding the read data amount Db1 to the data amount db to be written.

  Next, the process proceeds to step S213, where it is determined whether or not the calculated data amount Db1 has reached the allowable data amount Dbs of the overwriting prohibition EEPROM 132b1. If Db1 ≦ Dbs, the process proceeds to step S214, and a new abnormality is detected. After the data is written to the overwriting prohibition EEPROM 132b1, the timer interrupt process is terminated and the process returns to a predetermined main program.

On the other hand, when the determination result in step S213 is Db1> Dbs, the process proceeds to step S215, the initial data determination flag FTB is set to “1”, and then the process proceeds to step S216 for overwriting new abnormal data. After writing to the EEPROM 132b2, the timer interrupt process is terminated and the program returns to a predetermined main program.
If the determination result in step S210 is that the initial data determination flag FTB is “1”, the process directly proceeds to step S216.

As described above, by managing the initial data determination flags FTA and FTB in the data write management process, if there is a free storage capacity in the overwrite prohibition EEPROMs 132a1 and 132b1, the overwrite prohibition EEPROMs 132a1 and 132b1 are abnormal. By writing the data sequentially and writing abnormal data to the overwrite-allowing EEPROMs 132a2 and 132b2 in a state where the overwrite-inhibiting EEPROMs 132a1 and 132b1 are full, a large amount of abnormal data can be stored without being overwritten. In this case, a time-series data storage area for storing the above-described time-series data important as analysis data is secured in the overwriting-prohibiting EEPROMs 132a1 and 132b1, and other abnormal data is written in this time-series data storage area. The other abnormal data can be stored in a storage area other than the time-series data storage area until the storage capacity is full. For this purpose, it is determined whether or not the data to be written into the overwrite prohibiting EEPROMs 132a1 and 132b1 is time-series data, and whether or not the first time-series data is stored in the time-series data storage area. Thus, when it is time-series data, the first time-series data is stored in the time-series data storage area, and when it is the next time-series data, it is stored according to the remaining capacity of the other storage area. Just judge.
In this case, when an abnormality other than the abnormality including the time series data occurs, a plurality of abnormalities can be stored in the overwriting prohibition EEPROMs 132a1 and 132b1, and the abnormality analysis when the composite abnormality occurs is more accurately performed. Can be done.

  Further, as shown in FIG. 3, the abnormality diagnosis device 29 is connected to the main MCU 101 at the repair destination, and the main MCU 101 performs the data transfer process shown in FIG. It is possible to read out the initial abnormality analysis data and the normal abnormality analysis data stored in the EEPROMs 132a2 and 132b2 and perform accurate abnormality analysis. When this abnormality analysis is completed, a reset signal for resetting the initial data determination flags FTA and FTB to “0” is input from the abnormality diagnosis device 29 to the main MCU 101, whereby the initial abnormality analysis data is stored in the overwriting prohibition EEPROMs 132a1 and 132b1. Writing becomes possible.

  Here, as shown in FIG. 13, the data transfer process is started as a timer interrupt process at predetermined time intervals (for example, 2 msec) when the abnormality diagnosis device 29 is connected to the main MCU 101. First, step S220 is performed. Then, it is determined whether or not a data transfer request has been input from the abnormality diagnosis device 29. When a data transfer request has been input, the process proceeds to step S221, where the overwriting prohibition EEPROMs 132a1 and 132b1 and the overwriting permission EEPROMs 132a2 and 132b2 are transferred. The stored initial abnormality analysis data and normal abnormality analysis data are read out and transferred to the abnormality diagnosis device 29, and then the timer interruption process is terminated.

  If the determination result in step S220 indicates that no data transfer request has been input, the process proceeds to step S222 to determine whether a reset signal has been input. If no reset signal has been input, the timer allocation is continued. When the reset signal is input, the process proceeds to step S223, and the initial data determination flags FTA and FTB stored in the normal EEPROMs 132a1 to 132b2 are reset to “0”, and then the timer interrupt process is performed. To return to a predetermined main program.

In the data transfer process of FIG. 13, the processes in steps S222 and 223 correspond to the flag reset means.
Further, the EEPROMs 132a to 132b2 may be detachable, and after removing them, the EEPROM 132a to 132b2 may be attached to the abnormality diagnosis device 29 to perform abnormality analysis, and the abnormality diagnosis device 29 may reset the flags FTA and FTB. In this case, the abnormality diagnosis device 29 corresponds to the flag reset means.

Furthermore, in the above embodiment, the case where the motor drive current I _M is calculated by software processing executed by the central processing unit 32 has been described, but the present invention is not limited to this, and the steering assist command value calculator, center The motor drive current I _M may be calculated by hardware combining a response improvement circuit, an inertia compensator, a friction compensator, a differential compensator, a subtractor, a proportional calculator, an integral calculator, an adder, and the like. .

In the above embodiment, the case where the EEPROM is applied as the storage means has been described. However, the present invention is not limited to this, and any nonvolatile memory such as a flash memory can be applied. The type of time-series data written to the EEPROM can be arbitrarily set according to the abnormality that occurs.
Further, the steering assist control process of FIG. 5 may be terminated when an abnormality that affects the normal operation of the electric power steering apparatus is detected by the initial abnormality detection process and the constant abnormality detection process in the main MCU 101.
Furthermore, in the above-described embodiment, the case where the initial abnormality detection process and the constant abnormality detection process are performed only by the main MCU 101 has been described. However, the present invention is not limited to this, and the sub MCU 102 is also provided with an EEPROM to perform the initial abnormality detection process and the constant abnormality detection process. An abnormality detection process may be performed.

It is a schematic structure figure showing one embodiment of the present invention. FIG. 6 is a characteristic diagram of a torque detection signal detected by a steering torque sensor. FIG. 2 is a block diagram illustrating a specific configuration of the controller in FIG. 1. It is explanatory drawing which shows the structure of EEPROM. It is a flowchart which shows an example of the steering assistance control processing procedure performed with main and sub MCU. It is a characteristic diagram which shows a steering assistance command value calculation map. It is a flowchart which shows an example of the abnormality detection process procedure performed with main MCU. It is a flowchart which shows an example of an initial stage abnormality detection process procedure. It is a flowchart which shows an example of a torque sensor abnormality detection memory | storage process procedure. It is a flowchart which shows an example of a normal abnormality detection process sequence. It is explanatory drawing which shows the other structure of EEPROM. It is a flowchart which shows an example of the data write management processing procedure performed with main MCU. It is a flowchart which shows an example of the data transfer processing procedure performed with main MCU.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Steering wheel, 2 ... Steering shaft, 3 ... Steering torque sensor, 3m ... Main torque sensor, 3s ... Sub torque sensor, 8 ... Steering gear, 13 ... Electric motor, 14 ... Control device, 15 ... Battery, 16 ... Key Switch, 17 ... Vehicle speed sensor, 101 ... Main MCU, 102 ... Sub MCU, 110 ... Motor drive circuit, 112 ... Motor current detection circuit, 113 ... Motor angular velocity estimation circuit, 114 Temperature sensor, 130 ... ROM, 131 ... RAM, 132a1 ... EEPROM for initial abnormal overwrite prohibition, 132a2 ... EEPROM for initial abnormal overwrite allowance, 132b1 ... EEPROM for always abnormal overwrite prohibition, 132b2 ... EEPROM for always abnormal overwrite overwrite

Claims (7)

A steering assist control mechanism having an electric motor for applying a steering assist force to the steering system, an initial abnormality detecting means for detecting an abnormality at the start of operation of the steering assist control mechanism, and An abnormality that constantly detects abnormality, and an abnormality that stores abnormality analysis data including time-series data for analyzing the abnormality when the abnormality is detected by the initial abnormality detection means and the normal abnormality detection means. Data storage means,
The storage means corresponds to the initial abnormality detection means and the normal abnormality detection means individually, and overwrite storage prohibition areas for initial abnormality and normal abnormality for prohibiting overwriting of the abnormality analysis data, and the abnormality analysis data With an overwritable storage area for initial abnormality and always abnormality for overwriting storage,
The abnormality data storage means, when the abnormality of the initial abnormality detected by the detecting means steering assist control mechanism is the first abnormality analysis data, stored in said initial abnormality overwrite prohibition storage area, the second and subsequent initial abnormality When it is analysis data, it is stored in the initial abnormality overwriting storage area, and when the abnormality of the steering assist control mechanism detected by the normal abnormality detection means is the first abnormality analysis data, the overwriting prohibition for normal abnormality is prohibited. A control device for an electric power steering apparatus, wherein the control device is configured to store in a storage area and to store in the always-abnormal overwrite permitting storage area when the abnormality analysis data is the second and subsequent normal abnormality analysis data . 2. The electric power steering apparatus according to claim 1, wherein the abnormality data storage unit is configured to hold abnormality analysis data for a predetermined time before and after an abnormality is detected in time series . Control device. The abnormality analysis data includes time-series data of a detection period that is a first predetermined time for detecting a continuous abnormal state, and time-series data of a fixed period from the end of the detection period to a second predetermined time. in the control device for an electric power steering apparatus according to be composed in claim 2, wherein. The initial abnormality detection means includes an initial abnormality detection of a torque detection means included in the steering assist control mechanism, an initial abnormality detection of a control means included in the steering assist control mechanism, and an electric current detection means included in the steering assist control mechanism. It is configured to perform any one or more of initial abnormality detection, initial abnormality detection of an electric motor included in the steering assist control mechanism, initial abnormality detection of a power supply system, and initial abnormality detection of the storage device. 4. The control device for an electric power steering apparatus according to claim 1 , wherein the control apparatus is an electric power steering apparatus. The constant abnormality detection means includes a constant abnormality detection of a torque detection means included in the steering assist control mechanism, a constant abnormality detection of a control means included in the steering assist control mechanism, and a current detection means included in the steering assist control mechanism. One or a plurality of detections of normal abnormality, detection of normal abnormality of the electric motor included in the steering assist control mechanism, detection of normal abnormality of the vehicle speed detection means included in the steering auxiliary control mechanism, and detection of normal abnormality of the power supply system are performed. control device for an electric power steering apparatus according that you have been configured to any one of claims 1 to 4, characterized as. Data amount management means for managing the amount of data initially stored in the initial abnormality overwrite prohibition storage area and the constant abnormality overwrite prohibition storage area, and when the abnormality analysis data is generated next, the data amount management means It is determined whether or not the abnormality analysis data can be stored based on the amount of data managed in, and when it can be stored, the new abnormality analysis data is stored in the initial abnormality overwrite prohibition storage area and the constant abnormality overwrite prohibition storage. control device for an electric power steering apparatus according to any one of claims 1 to 5, characterized that you have a storage data adding means for adding stored in the area. The data amount managing means is configured to store and manage a data amount stored in the initial abnormality overwrite prohibition storage area and the constant abnormality overwrite prohibition storage area in a nonvolatile memory. The control apparatus of the electric power steering apparatus according to claim 6 .

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