JP5187220B2 - Electric power steering device - Google Patents

Description

  The present invention relates to an electric power steering apparatus in which an assist torque by a motor is applied to a steering mechanism of a vehicle, and in particular, a degree of possibility that a definite abnormality occurs in each part of a motor control unit and a sensor of the electric power steering apparatus. The present invention relates to an electric power steering apparatus having a function of making a stepwise determination.

  An electric power steering device for energizing a vehicle steering device with an auxiliary load by a rotational force of a motor energizes an auxiliary load to a steering shaft or a rack shaft by a transmission mechanism such as a gear or a belt via a speed reducer. It is supposed to be. Such a conventional electric power steering apparatus performs feedback control of motor current in order to accurately generate assist torque (steering assist force). In the feedback control, the motor applied voltage is adjusted so that the difference between the current command value and the motor current detection value becomes small. Generally, the adjustment of the motor applied voltage is a duty of PWM (pulse width modulation) control. This is done by adjusting the tee ratio.

  Here, the general configuration of the electric power steering apparatus will be described with reference to FIG. It is connected to. The column shaft 2 is provided with a torque sensor 10 that detects the steering torque of the handle 1, and a motor 20 that assists the steering force of the handle 1 is connected to the column shaft 2 via the reduction gear 3. The control unit 30 that controls the electric power steering device is supplied with electric power from the battery 14 and is also input with an ignition signal via the ignition key 11. The control unit 30 detects the steering torque T detected by the torque sensor 10. The current command value I of the assist command is calculated based on the vehicle speed V detected by the vehicle speed sensor 12, and the current supplied to the motor 20 is controlled based on the calculated current command value I.

  The control unit 30 is mainly composed of a CPU (including MPU and MCU). FIG. 11 shows general functions executed by a program inside the CPU.

  The function and operation of the control unit 30 will be described with reference to FIG. 11. The steering torque T detected by the torque sensor 10 is input to the current command value calculation unit 32, and the vehicle speed V detected by the vehicle speed sensor 12 is also the current command. The value is input to the value calculation unit 32. The current command value calculation unit 32 refers to the assist map stored in the memory 33 based on the input steering torque T and vehicle speed V, and a current command value I that is a control target value of the current supplied to the motor 20. To decide. The current command value I is input to the subtraction unit 30A and is also input to the feedforward differential compensation unit 34 for increasing the response speed. The deviation (Ii) of the subtraction unit 30A is input to the proportional calculation unit 35. At the same time, it is input to the integral calculation unit 36 for improving the characteristics of the feedback system, and its proportional output is input to the addition unit 30B. The outputs of the differential compensator 34 and the integral compensator 36 are also added to the adder 30B, and the current control value E, which is the addition result of the adder 30B, is input to the motor drive circuit 37 as a motor drive signal. Electric power is supplied from the battery 14 to the motor drive circuit 37, the motor current value i of the motor 20 is detected by the motor current detector 38, and the motor current value i is input to the subtractor 30A and fed back.

  In addition, an abnormality diagnosis unit 40 is provided. The abnormality diagnosis unit 40 performs initial diagnosis or operation of the voltage of the battery 14, the abnormality of the torque sensor 10, the abnormality (including failure) of the motor 20 or the motor drive circuit 37, and the like. Diagnosis is performed with the normal diagnosis, and when an abnormality occurs, processing such as assist stop is performed.

  In such an electric power steering apparatus, in the control unit abnormality diagnosis performed at the time of manufacture of the control unit and the electric power steering apparatus abnormality diagnosis performed at the time of inspection in the production line of the electric power steering apparatus, the control unit An inspection device 50 as shown in FIG. 12 is connected, and an inspection for performing an abnormality diagnosis is executed.

  FIG. 12 is a block diagram illustrating a configuration example of the inspection apparatus 50. The inspection device 50 includes a power supply unit 57 that supplies power to the control unit of the electric power steering device, a CPU 51 that controls the entire inspection device 50 to execute inspection, a ROM 52 that stores and holds inspection programs, parameters, and the like. RAM 53 for temporarily storing calculation processing results, display unit 54 for displaying inspection results, etc., input unit 55 for performing various inputs such as parameters and setting changes, and setting values and programs input to input unit 55 A command value and the like are output to the electric power steering apparatus, and an input / output interface (IF) unit 56 and the like to which detection values from various sensors and the like are input.

  As shown in FIG. 12, the electric power steering apparatus is subjected to an inspection as to whether or not the electric power steering apparatus behaves normally after mounting a torque sensor or a motor for detecting steering torque in the production line. It is executed by the inspection device 50. However, since the control characteristics of the electric power steering device are generally different for each vehicle type installed, the individual steering devices are inspected according to the control characteristics in the production line where a plurality of types of steering devices are mixed. It takes a lot of time and effort to do so, and is a major factor that hinders productivity.

  Therefore, the steering device inspection device disclosed in Japanese Patent Application Laid-Open No. 2003-261046 (Patent Document 1) has a control characteristic for operating a steering actuator that generates a steering force based on a detected torque of a torque sensor. An inspection control unit configured to be changeable according to the type of steering device is provided, and a desired inspection for a plurality of types of steering devices mixed in a production line can be easily and reliably performed. ing.

Japanese Patent Laid-Open No. 2003-261046

  However, the steering device inspection device disclosed in Patent Document 1 can diagnose an abnormality of the electric power steering device before being mounted on the vehicle, but there is a possibility that the electric power steering device will be abnormal in the future. It is difficult to determine how much it is. Therefore, there is a possibility that an electric power steering apparatus or a vehicle having a problem with safety and comfort may be shipped to the market.

  The present invention has been made under the circumstances as described above, and an object of the present invention is to identify whether the product is likely to cause an abnormality in the future or the product that is low in several stages, and an electric power steering device Electric power steering can be reliably prevented from shipping defective products to the market, and safety and comfort can be improved by replacing parts while the electric power steering device is in a safe state To provide an apparatus.

The present invention includes a control means for driving and controlling a motor that applies assist torque to a steering mechanism of a vehicle relates to an electric power steering apparatus having a plurality of abnormality diagnosis means for diagnosing each part of the abnormality, the object of the present invention The abnormality diagnosing means detects an uncertain abnormality that does not result in confirmation of each part, and a count value a that is the number of times the uncertain abnormality is detected in the abnormality diagnosis at the time of manufacturing, and an abnormality diagnosis performed at the time of inspection of the manufacturing line And a count value b that is the number of times that the indeterminate abnormality is detected, and a count value c that is the number of times that the indeterminate abnormality is detected in the abnormality diagnosis performed during the assist operation at the stage of being mounted on the vehicle. Based on the count value a, the count value b, and the count value c, the degree of possibility of occurrence of a confirmed abnormality in each unit is determined in stages. It is achieved by providing that function.

  Further, the above object of the present invention is more effectively achieved by providing a function of notifying the driver of the result of the stepwise determination.

  According to the electric power steering device of the present invention, the stepwise determination is made on the degree of possibility of the confirmed abnormality based on the count value that is the number of times the uncertain abnormality that has not been confirmed is detected. Therefore, it is possible to identify the products that are likely to cause abnormalities in the future as low-grade products by dividing them into several levels, and to ensure that defective products of the electric power steering device are shipped to the market. Can be prevented.

  In addition, the safety and comfort of the electric power steering apparatus can be further improved by exchanging parts related to the abnormality while the electric power steering apparatus is in a safe state.

It is a block diagram which shows the structural example of the control unit of the electric power steering apparatus which concerns on 1st Embodiment of this invention. It is a block diagram which shows the structural example of the abnormality diagnosis means of the electric power steering apparatus which concerns on 1st Embodiment of this invention. It is a flowchart which shows the operation example of the abnormality diagnosis of the electric power steering apparatus which concerns on 1st Embodiment of this invention. It is a block diagram which shows the structural example of the control unit of the electric power steering apparatus which concerns on 2nd Embodiment of this invention. It is a flowchart which shows the operation example of the abnormality diagnosis of the electric power steering apparatus which concerns on 2nd Embodiment of this invention. It is a block diagram which shows the structural example of the control unit of the electric power steering apparatus which concerns on 3rd Embodiment of this invention. It is a flowchart which shows the operation example of abnormality diagnosis of the electric power steering apparatus which concerns on 3rd Embodiment of this invention. It is a block diagram which shows the structural example of the abnormality diagnosis means of the electric power steering apparatus which concerns on 4th Embodiment of this invention. It is a flowchart which shows the operation example of abnormality diagnosis of the electric power steering apparatus which concerns on 4th Embodiment of this invention. It is a figure showing an example of composition of a general electric power steering device. It is a block diagram which shows the structural example of the control unit of the conventional electric power steering apparatus. It is a block diagram which shows the example of the test | inspection apparatus of a general electric power steering apparatus.

The electric power steering device according to the present invention stores, as a count value, the number of times that the abnormality diagnosis means or the inspection device provided in the control unit of the electric power steering device detects an uncertain abnormality that does not reach the final value. By making a step-by-step judgment on the degree of possibility of occurrence of an abnormality determined based on the product, it is possible to identify the product that is likely to cause an abnormality in the future by dividing it into several levels. Yes.
As a result, it is possible to reliably prevent defective products of the electric power steering device from being shipped to the market, and the electric power steering device can replace the parts related to the abnormality while the electric power steering device is in a safe state. The safety and comfort of the steering device can be further enhanced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram illustrating a configuration example of a control unit 30A of the electric power steering apparatus according to the first embodiment of the present invention. The motor drive control unit 301 of the control unit 30A collectively shows a plurality of control elements as shown in FIG. 10, calculates the current command value I based on the steering torque T and the vehicle speed V, and Based on the value I, the motor 20 is driven and controlled. Further, the control unit 30A includes a plurality of abnormality diagnosis means for performing abnormality diagnosis (including failure diagnosis) on each part of the electric power steering apparatus. In the example of FIG. Diagnostic means 61A, abnormality diagnosis means 62A for making an abnormality diagnosis of motor drive control section 301, and abnormality diagnosis means 63A for making an abnormality diagnosis of motor 20 are provided.

  As shown in FIG. 1, in the first embodiment, an inspection device 50 is connected to the control unit 30 </ b> A, and power is supplied to the control unit 30 </ b> A from the power supply unit 57 of the inspection device 50. The abnormality confirmation signals CF1 to CF3 and abnormality determination signals Js1 to Js3 from the abnormality diagnosis means 61A to 63A are input to the input / output IF unit 56 of the inspection device 50, and are determined in each part of the electric power steering device by the input signals. Step-by-step determination results regarding the presence / absence of abnormality and the degree of possibility of occurrence of abnormality determined in each part of the electric power steering apparatus are displayed on the display unit 54 of the inspection apparatus 50.

  The abnormality diagnosis means 61A is configured as shown in FIG. 2, for example, and detects an abnormality (including a failure) of the torque sensor 10 during the assigned diagnosis time, and an abnormality (for example, the detected abnormality is confirmed) When the disconnection or the output value deviates from the reference value), the abnormality detection unit 611 that outputs the abnormality confirmation signal CF1 and inputs the abnormality confirmation signal CF1 to the inspection apparatus 50; A count value storage unit 612 that stores a count value N1 that is the number of times that the abnormality detection unit 611 has detected an upper limit value and a lower limit value of the reference value), and an abnormality that has been established in the torque sensor 10 based on the count value N1 occurs. A determination unit 613 that performs stepwise determination (“A”, “B”, “C”) on the degree of possibility, outputs an abnormality determination signal Js1, and inputs the abnormality determination signal Js1 to the inspection apparatus 50; To have.

  The abnormality diagnosis means 62A and 63A have the same configuration as the abnormality diagnosis means 61A, and the abnormality diagnosis means 62 detects an abnormality of the motor control drive unit 301 during the assigned diagnosis time, and the detected abnormality is not shown. An abnormality detection unit 621 that outputs an abnormality confirmation signal CF2 and inputs the abnormality confirmation signal CF2 to the inspection device 50 when the abnormality is confirmed (for example, when the disconnection or control signal deviates from a reference value); The count value storage unit 622 that stores the count value N2 that is the number of times the control signal is close to the upper and lower limit values of the reference value, and the possibility that an abnormality that has been established in the motor control drive unit 301 based on the count value N2 may occur. And a determination unit 623 for inputting an abnormality determination signal Js2 to the inspection apparatus 50. Further, although not shown, the abnormality diagnosis means 63 detects an abnormality of the motor 20 during the assigned diagnosis time, and outputs an abnormality confirmation signal CF3 when the detected abnormality is a confirmed abnormality (for example, disconnection or the like). Then, an abnormality detection unit 631 that is input to the inspection apparatus 50, a count value storage unit 632 that stores a count value N3 that is the number of detected indeterminate abnormalities (for example, when the resistance value is greater than a reference value), and a count value And a determination unit 633 that performs stepwise determination on the degree of possibility of occurrence of a confirmed abnormality in the motor 20 based on N3, and inputs an abnormality determination signal Js3 to the inspection apparatus 50.

  The diagnosis time during which the abnormality detection units 611 to 631 of the abnormality diagnosis means 61A to 63A detect abnormality may be arbitrary, and may be independent for each of the abnormality diagnosis means 61A to 63A. Further, the number of abnormality diagnosis means is not limited to three, and an arbitrary number of abnormality diagnosis means may be provided for each part of the electric power steering apparatus that needs to diagnose abnormality.

  In the first embodiment, the inspection device 50 is connected to the control unit 30A, power is supplied from the inspection device 50 to the control unit 30A, abnormality diagnosis is performed, and the result of diagnosis is displayed on the inspection device 50. Thus, the abnormality diagnosis of the first embodiment is an abnormality diagnosis process of the control unit 30A performed at the time of manufacture of the control unit 30A or an abnormality of the electric power steering device performed at the time of inspection in the production line of the electric power steering device. Performed in the diagnostic process.

  An operation example of abnormality diagnosis by the abnormality diagnosis means 61A of the first embodiment will be described with reference to the flowchart of FIG.

  First, the inspection device 50 is connected to the control unit 30A of the electric power steering apparatus, and the control unit 30A is turned on to prepare for abnormality diagnosis (step S101).

  The abnormality detection unit 611 of the abnormality diagnosis unit 61A detects abnormality of the torque sensor 10 for a predetermined diagnosis time, and counts “+1” in the count value storage unit 612 in the case of an indefinite abnormality (step S102). When the abnormality detection unit 611 detects a confirmed abnormality (step S103), the abnormality detection unit 611 outputs the abnormality confirmation signal CF1 and inputs the abnormality confirmation signal CF1 (step S104), and abnormality diagnosis by the abnormality diagnosis unit 61A. The process ends.

  In addition, when the abnormality detection unit 611 does not detect the abnormality determined in step S <b> 103, the determination unit 613 determines, based on the count value N <b> 1 that is the number of times of detection of the indeterminate abnormality stored in the count value storage unit 612. A step-by-step determination is made as to the degree of possibility of occurrence of a confirmed abnormality in the torque sensor 10. That is, the determination unit 613 compares the count value N1 with the count threshold value X1 (step S105), and if the count value N1 is equal to or less than the count threshold value X1, the level of the possibility of occurrence of a confirmed abnormality in the torque sensor 10 is determined. It is determined that “A” (the possibility of occurrence of a confirmed abnormality is low) (step S106). On the other hand, if the count value N1 is greater than the count threshold value X1, the count value N1 is further compared with the count threshold value X2 (> X1) (step S107). If the count value N1 is less than or equal to the count threshold value X2, the torque sensor 10 The degree of possibility of occurrence of the confirmed abnormality is determined to be level “B” (the possibility of occurrence of the confirmed abnormality is medium) (step S108), and if the count value N1 is greater than the count threshold value X2, the torque The degree of possibility of occurrence of a confirmed abnormality in the sensor 10 is determined as level “C” (the possibility that a confirmed abnormality will occur is high) (step S109).

  The stepwise determination results (“A”, “B”, “C”) of the determination unit 613 regarding the degree of possibility of occurrence of a confirmed abnormality in the torque sensor 10 are output as the abnormality determination signal Js1 (step S110). Then, the abnormality diagnosis by the abnormality diagnosing means 61 is completed after being input to the inspection device 50.

  In the abnormality diagnosis by the other abnormality diagnosis means 62A and 63A, after the inspection device 50 is connected to the control unit 30A of the electric power steering apparatus, a confirmed abnormality is detected as in the abnormality diagnosis operation of the abnormality diagnosis means 61A. In this case, abnormality confirmation signals CF2 and CF3 are output and input to the inspection apparatus 50, respectively, and if a confirmed abnormality is not detected, a stepwise judgment result on the degree of possibility that a confirmed abnormality will occur in the future ( "A", "B", and "C") are output as abnormality determination signals Js2 and Js3, respectively, and input to the inspection apparatus 50.

  In the first embodiment, as shown in the flowchart of FIG. 3, when the determination of the possibility of occurrence of a confirmed abnormality is made in three stages, for example, the result of the stepwise determination is level “C” In this case, it is possible to prevent defective products of the electric power steering apparatus from being shipped to the market by exchanging the products (parts related to the abnormality).

  In the first embodiment, stepwise determination as to the degree of possibility of occurrence of an abnormality is performed using the two count threshold values X1 and X2, but the determination unit of each abnormality diagnosis unit performs the steps. The number of count threshold values used when making a general determination can be arbitrarily set, and the count threshold value can be set independently for each abnormality diagnosis means.

  Table 1 shows, as a specific example, the count value N and the count threshold value X of the twelve abnormality diagnosis units 1 to 12 and the abnormality diagnosis unit 1 to 12 for each count value N and the count threshold value X. Is output and is input to the inspection apparatus 50.

表１の例では、異常診断手段１〜１２のカウント閾値Ｘの数は１個になっており、各異常診断手段１〜１２は、それぞれのカウント値Ｎがカウント閾値Ｘより大きい場合にのみ、異常判断信号Ｊｓを出力するようになっている。

In the example of Table 1, the number of the count threshold value X of the abnormality diagnosis means 1 to 12 is 1, and each abnormality diagnosis means 1 to 12 is only when each count value N is larger than the count threshold value X. An abnormality determination signal Js is output.

  As shown in Table 1, the abnormality diagnosis means 1 to 3, the abnormality diagnosis means 5, the abnormality diagnosis means 7, and the abnormality diagnosis means 9 to 12 all have a count value N of “0”. And 8, the count value N is “1”. These abnormality diagnosis means 1 to 5 and abnormality diagnosis means 7 to 12 do not output the abnormality determination signal Js because the count value N is smaller than the count threshold value X. On the other hand, the abnormality diagnosis means 6 outputs the abnormality determination signal Js because the value 5 of the count value N is larger than the value 4 of the count threshold X.

  Next, a configuration example of the control unit 30B of the electric power steering apparatus according to the second embodiment of the present invention will be described with reference to FIG.

  Also in the second embodiment, the inspection device 50 is connected to the control unit 30B, and power is supplied to the control unit 30B from the power supply unit 57 of the inspection device 50. The control unit 30B includes an abnormality diagnosis unit 61B that detects an abnormality in the torque sensor 10 during the assigned diagnosis time, an abnormality diagnosis unit 62B that detects an abnormality in the motor drive control unit 301 during the assigned diagnosis time, and an assignment Abnormality diagnosis means 63B for detecting an abnormality of the motor 20 for a given diagnosis time, and the abnormality diagnosis means 61B to 63B, when the detected abnormality is a confirmed abnormality, respectively, abnormality confirmation signals CF1 to CF3. Is input to the input / output IF unit 56 of the inspection apparatus 50, and when the detected abnormality is an uncertain abnormality that does not reach definiteness, uncertain abnormality signals UF1 to UF3 are output to input / output the inspection apparatus 50. The data is input to the IF unit 56. The other configuration of the control unit 30B shown in FIG. 4 is the same as that of the control unit 30A of the first embodiment shown in FIG. 1, and the inspection apparatus 50 shown in FIG. It has a function for storing a value (RAM 53) and a function for determining the possibility of occurrence of a confirmed abnormality (CPU 51).

  In the second embodiment, the RAM 53 in the inspection device 50 stores the count values N1 to N3 that are the number of times that the indefinite abnormality is detected in the abnormality diagnosis means 61B to 63B, and the CPU 51 is based on the count values N1 to N3. Thus, a stepwise determination is made as to the degree of possibility of occurrence of a confirmed abnormality in the torque sensor 10, the motor drive control unit 301, and the motor 20, respectively. The inspection apparatus 50 displays the result of the stepwise determination on the display unit 54, and when the abnormality confirmation signals CF1 to CF3 are input, the abnormality determined in the torque sensor 10, the motor drive control unit 301, and the motor 20, respectively. The occurrence is displayed on the display unit 54.

  Note that the diagnosis time for detecting the abnormality by the abnormality diagnosis means 61B to 63B may be arbitrary, and may be independent for each of the abnormality diagnosis means 61B to 63B. Also, the number of abnormality diagnosis means is not limited to three, and an arbitrary number of abnormality diagnosis means may be provided for each part of the electric power steering apparatus that needs to perform abnormality diagnosis. In the abnormality diagnosis of the second embodiment, the inspection device 50 is connected to the control unit 30B to perform abnormality diagnosis, and the abnormality diagnosis process of the control unit 30B performed at the time of manufacture of the control unit 30B is performed. This is performed in an abnormality diagnosis process of the electric power steering apparatus performed at the time of inspection in the production line of the electric power steering apparatus.

  An operation example of abnormality diagnosis by the abnormality diagnosis means 61B and the inspection apparatus 50 in the second embodiment will be described with reference to the flowchart of FIG.

  First, the inspection device 50 is connected to the control unit 30B of the electric power steering device, and the control unit 30B is turned on to prepare for abnormality diagnosis (step S201). Then, the abnormality diagnosis means 61B detects an abnormality of the torque sensor 10, and if the detected abnormality is a confirmed abnormality, it outputs an abnormality confirmation signal CF1 and inputs it to the input / output IF unit 56 of the inspection device 50 for detection. If the abnormality is an uncertain abnormality, an uncertain abnormality signal UF1 is output and input to the input / output IF unit 56 of the inspection apparatus 50 (step S202).

  The inspection apparatus 50 determines whether or not the abnormality confirmation signal CF1 is input (step S203). When the abnormality determination signal CF1 is input to the inspection apparatus 50, the display unit 54 of the inspection apparatus 50 displays the torque sensor 10. Is displayed (step S204), and the abnormality diagnosis process by the abnormality diagnosis means 61B is terminated.

  The inspection device 50 stores the number of times the uncertain abnormality signal UF1 is input from the abnormality diagnosis unit 61B as the count value N1. Further, when the abnormality confirmation signal CF1 is not input to the inspection apparatus 50 in the above step S203, the inspection apparatus 50 determines the degree of possibility that the abnormality determined in the torque sensor 10 will occur based on the count value N1. That is, the count value N1 is compared with the count threshold value X1 (step S205). If the count value N1 is equal to or less than the count threshold value X1, the degree of possibility that the torque sensor 10 is determined to be abnormal is set to the level “A” ( It is determined that there is a low possibility that a confirmed abnormality will occur (step S206). On the other hand, when the count value N1 is larger than the count threshold value X1, the count value N1 is compared with the count threshold value X2 (> X1) (step S207), and when the count value N1 is less than or equal to the count threshold value X2, the torque sensor 10 When the count value N1 is larger than the count threshold value X2, it is determined that the level of the possibility of occurrence of the confirmed abnormality is level “B” (the possibility of occurrence of the confirmed abnormality is medium) (step S208). The degree of possibility of occurrence of a confirmed abnormality in the torque sensor 10 is determined as level “C” (the possibility of occurrence of a confirmed abnormality is high) (step S209).

  Judgment results (“A”, “B”, “C”) about the degree of possibility of occurrence of a confirmed abnormality in the torque sensor 10 are displayed on the display unit 54 of the inspection device 50 (step S210), and abnormality diagnosis means The abnormality diagnosis process by 61B ends.

  Regarding the abnormality detected by the other abnormality diagnosis means 62B and 63B, the inspection apparatus 50 performs processing according to the procedure after step S203 of the flowchart shown in FIG. 5, and the abnormality confirmation signals CF2 and CF3 are respectively sent to the inspection apparatus 50. If input, the display unit 54 displays that a confirmed abnormality has occurred. When the abnormality confirmation signals CF2 and CF3 are not input to the inspection device 50, the inspection device 50 stores the number of times the uncertain abnormality signals UF2 and UF3 are input as the count values N2 and N3, respectively. Based on N2 and N3, a stepwise determination is made as to the degree of possibility that an abnormality determined in the future will occur, and the result of the stepwise determination is displayed on the display unit 54.

  In the second embodiment, when the determination of the possibility of occurrence of the confirmed abnormality is made in three stages, for example, when the result of the stepwise determination is level “C”, the product (related to the abnormality) By exchanging the parts, it is possible to prevent defective products of the electric power steering apparatus from being shipped to the market. In the second embodiment, in the inspection apparatus, the number of times that an indefinite abnormality is detected in each part of the electric power steering apparatus is stored as a count value, and a possibility that an abnormality fixed in each part based on the count value may occur. Therefore, the memory capacity of the control unit 30B can be reduced.

  In the second embodiment, the stepwise determination as to the degree of possibility of occurrence of a confirmed abnormality is made using the two count threshold values X1 and X2, but the inspection apparatus 50 causes the occurrence of an abnormality. The number of count thresholds used when making a stepwise determination as to the degree of possibility of performing can be arbitrarily set, and the count threshold value can be set independently for each abnormality diagnosis means.

  Next, a configuration example of the control unit 30C of the electric power steering apparatus according to the third embodiment of the present invention will be described with reference to FIG.

  In the third embodiment, a memory inspection device 70 and a display unit 71 are provided in the control unit 30C. The memory inspection device 70 includes abnormality confirmation signals CF1 to CF3 and abnormality determination from the abnormality diagnosis means 61A to 63A. Signals Js1 to Js3 are input. The abnormality diagnosing means 61A to 63A are the same as in the first embodiment, and the memory inspection device 70 is configured so that when the abnormality confirmation signals CF1 to CF3 are input, the torque sensor 10, the motor drive control unit 301, and the motor 20 respectively. Is stored, and when the abnormality determination signals Js1 to Js3 are input, the degree of possibility that the determined abnormality occurs in the torque sensor 10, the motor drive control unit 301, and the motor 20, respectively. The result of stepwise judgment on “(A”, “B”, “C”) is stored. Further, the memory inspection device 70 may have a confirmed abnormality occurring in the torque sensor 10, the motor drive control unit 301, or the motor 20, or a certain abnormality that may be confirmed in the future, so that the driver can check. The result of stepwise judgment on the degree is displayed on the display unit 71. The control unit 30C has the same configuration as that of the first embodiment, except that the control unit 30C includes the memory inspection device 70 and the display unit 71 and does not connect the inspection device 50.

  In the third embodiment, when the ignition key is turned on and the power of the control unit 30C is turned on, an abnormality diagnosis of each part of the electric power steering device is performed, and the electric power steering device is a vehicle. After being installed in the vehicle, before or during the operation when the electric power steering device applies assist torque to the steering mechanism of the vehicle, an abnormality diagnosis of each part of the electric power steering device is performed and the result of the abnormality diagnosis is notified to the driver It has become.

  An operation example in which the abnormality diagnosis unit 61A performs abnormality diagnosis, the memory inspection device 70 stores the diagnosis result, and displays the diagnosis result on the display unit 71 will be described with reference to the flowchart of FIG.

  First, the driver turns on the ignition key to turn on the power of the control unit 30C (step S301), and performs abnormality diagnosis at a predetermined cycle before starting the assist of the electric power steering apparatus or during a predetermined operation. The abnormality detector 611 of the abnormality diagnosis means 61A detects an abnormality of the torque sensor 10 for a predetermined diagnosis time (step S302), and outputs an abnormality confirmation signal CF1 when a confirmed abnormality is detected (step S303). To the memory inspection device 70 (step S304). The memory inspection device 70 displays on the display unit 71 that a confirmed abnormality has occurred in the torque sensor 10 to notify the driver (step S311).

  In step S305, when the abnormality detection unit 611 does not detect the determined abnormality, the determination unit 613 determines that the torque sensor is based on the count value N1 that is the number of times of indeterminate abnormality detection stored in the count value storage unit 612. Judgment is made as to the degree of possibility of occurrence of the abnormality determined in 10. That is, the count value N1 is compared with the count threshold value X1 (step S305), and when the count value N1 is equal to or less than the count threshold value X1, the degree of possibility of occurrence of a confirmed abnormality in the torque sensor 10 is set to the level “A” ( It is determined that there is a low possibility that a confirmed abnormality will occur (step S306). On the other hand, if the count value N1 is greater than the count threshold value X1, the count value N1 is compared with the count threshold value X2 (> X1) (step S307). If the count value N1 is less than or equal to the count threshold value X2, the torque sensor 10 is confirmed. If the count value N1 is greater than the count threshold value X2, it is determined that the level of the possibility of occurrence of the abnormality is level “B” (the possibility of occurrence of the confirmed abnormality is medium) (step S308). The degree of possibility of occurrence of the abnormality determined to be 10 is determined as level “C” (the possibility of occurrence of the confirmed abnormality is high) (step S309).

  The stepwise judgment results (“A”, “B”, “C”) by the judgment unit 613 regarding the degree of possibility of occurrence of a confirmed abnormality in the torque sensor 10 are output as the abnormality judgment signal Js1, and the memory inspection device 70 (step S310). In order to notify the driver, the memory inspection device 70 displays a stepwise determination result on the degree of possibility of occurrence of a confirmed abnormality in the torque sensor 10 on the display unit 71 (step S311).

  The other abnormality diagnosis means 62A and 63A perform abnormality diagnosis of the motor drive control unit 301 and the motor 20 in the same procedure as described above, and the memory inspection device 70 stores the result of the abnormality diagnosis and informs the driver. Is displayed on the display unit 71.

  According to the third embodiment, the determination of the possibility of occurrence of a confirmed abnormality is made in three stages. For example, when the result of the stepwise determination is level “C”, the product (abnormality) is determined. It is possible to prevent defective products of the electric power steering apparatus from being shipped to the market by exchanging the parts). Further, safety and comfort can be improved by replacing the parts while the electric power steering apparatus is in a safe state according to the result of the stepwise determination.

  6 shows the abnormality diagnosing means 61A to 63A, the number of abnormality diagnosing means is not limited to three, but each part and sensor of the electric power steering apparatus that needs to diagnose the abnormality Any number may be provided. In the third embodiment, stepwise determination as to the degree of possibility of occurrence of abnormality is made using the two count threshold values X1 and X2, but the determination unit of each abnormality diagnosis means The number of count thresholds used when making a stepwise determination as to the degree of the possibility of occurrence of an error can be arbitrarily set, and the count threshold value can be set independently for each abnormality diagnosis means.

  By the way, the abnormality diagnosis of the control unit of the electric power steering apparatus is an abnormality diagnosis (at the time of manufacture) at the stage of manufacturing the control unit performed by the control unit manufacturer, and the electric power steering apparatus performed by the electric power steering apparatus manufacturer. It is often performed in three steps: abnormality diagnosis on the production line (at the time of inspection) and abnormality diagnosis (at the time of assist operation) at the stage where the electric power steering device performed by the automobile manufacturer is mounted on the vehicle. Therefore, in the fourth embodiment of the present invention, a step-by-step determination is made as to the possibility of occurrence of a confirmed abnormality in the future, based on the total number of uncertainties in the abnormality diagnosis performed in a plurality of steps as described above. Do.

  FIG. 8 shows a configuration example of the abnormality diagnosis unit 62C provided in the control unit 30D (not shown) of the electric power steering apparatus according to the fourth embodiment of the present invention. The control unit 30D in the fourth embodiment is the same as the control units 30A, 30B, and 30C shown in FIGS. 1, 3, and 6, respectively, and includes a motor drive control unit 301. 6 shows only the abnormality diagnosis means 62C for detecting the abnormality of the motor drive control unit 301, the abnormality detection means 61C for detecting the abnormality of the torque sensor 10 and the abnormality detection means 63C for detecting the abnormality of the motor 20 are provided. doing.

  An abnormality diagnosis unit 62C shown in FIG. 8 performs abnormality diagnosis of the motor drive control unit 301 of the control unit 30D, and an abnormality detection unit 621 that outputs an abnormality confirmation signal CF2 when a confirmed abnormality is detected. A count value storage unit 622 that stores a count value that is the number of times that an uncertain abnormality that has not been finalized by the unit 621 is detected, and a motor drive control unit 301 that is based on the count value stored in the count value storage unit 622 in the future. And a determination unit 623 that performs stepwise determination on the degree of possibility of occurrence of the confirmed abnormality and outputs an abnormality determination signal Js2.

  The count value storage unit 622 stores a count value storage unit (a) that stores a count value N2a that is the number of times that the abnormality detection unit 621 has detected an uncertain abnormality in an abnormality diagnosis performed at the time of manufacture of the control unit 30D. ) 622a, and a count value storage unit (b) 622b that stores a count value N2b that is the number of times the abnormality detection unit 621 has detected an indefinite abnormality in the abnormality diagnosis performed during the inspection in the production line of the electric power steering device, A count value storage unit that stores a count value N2c that is the number of times the abnormality detection unit 621 has detected an uncertain abnormality in the abnormality diagnosis performed during or before the assist operation when the electric power steering device is mounted on the vehicle ( c) 622c.

  In such a configuration, the abnormality diagnosis means 62C performs abnormality diagnosis of the motor drive control unit 301 (a) at the time of manufacture when the control unit 30D is manufactured, (b) at the time of inspection on the manufacturing line of the electric power steering device, (C) An example of the operation performed during the assist operation at the stage where the electric power steering apparatus is mounted on the vehicle will be described with reference to the flowcharts of FIGS.

  When manufacturing the control unit 30D, abnormality diagnosis is performed according to the flowchart shown in FIG. First, the power of the control unit 30D is turned on to prepare for abnormality diagnosis by the abnormality diagnosis means 62C (step S401), and the abnormality detection unit 621 detects abnormality of the motor drive control unit 301 (step S402). When the abnormality detection unit 621 detects a confirmed abnormality (step S403), the abnormality confirmation signal CF2 is input to the inspection device 50 or the memory inspection device 70 (step S404), and a confirmed abnormality has occurred in the motor drive control unit 301. Is displayed on the display unit, and the abnormality diagnosis is terminated.

When the abnormality detection unit 621 does not detect a confirmed abnormality in step S403, the count value storage unit (a) 622a sets the number of times that the abnormality detection unit 621 has detected an uncertain abnormality of the motor drive control unit 301 to “+1”. Is stored as the count value N2a.
Thereafter, the process proceeds to (b) abnormality diagnosis (during inspection) on the production line of the electric power steering apparatus, and abnormality diagnosis is performed according to the flowchart shown in FIG. Similarly to the flowchart of FIG. 9A, first, the power of the control unit 30D is turned on to prepare for abnormality diagnosis (step S501), and the abnormality detection unit 621 of the abnormality diagnosis unit 62C detects the abnormality of the motor drive control unit 301. Detection is performed (step S502). When the abnormality detection unit 621 detects a confirmed abnormality (step S503), the abnormality confirmation signal CF2 is input to the inspection device 50 or the memory inspection device 70 (step S504), and a confirmed abnormality has occurred in the motor drive control unit 301. Is displayed on the display unit, and the abnormality diagnosis is terminated.

  When the abnormality detection unit 621 does not detect the determined abnormality in step S503, the count value storage unit (b) 622b determines the number of times that the abnormality detection unit 621 has detected the uncertain abnormality of the motor drive control unit 301 {+1 } And store it as a count value N2B. And (c) it progresses to the abnormality diagnosis at the time of assist operation | movement in the stage which mounted the electric power steering device in the vehicle.

  During the assist operation at the stage where the electric power steering device is mounted on the vehicle, abnormality diagnosis is performed according to the flowchart shown in FIG. First, the ignition key 11 is turned on to turn on the power of the control unit 30D, and preparations for abnormality diagnosis are made (step S601). Then, the abnormality detection unit 621 of the abnormality diagnosis unit 62C detects the abnormality of the motor drive control unit 301 (step S602), and when the confirmed abnormality is detected (step S603), the abnormality confirmation signal CF2 is detected by the inspection device 50 or It inputs into the memory test | inspection apparatus 70 (step S604), it displays on the display part that the abnormality which settled in the motor drive control part 301 generate | occur | produced, and complete | finishes abnormality diagnosis.

  When the abnormality detection unit 621 does not detect a confirmed abnormality in step S603, the count value storage unit (c) 622c sets the number of times that the abnormality detection unit 621 has detected an uncertain abnormality of the motor drive control unit 301 to “+1”. Is stored as the count value N2c (step S605). Thereafter, the determination unit 623 of the abnormality diagnosis unit 62 may generate a determined abnormality in the motor drive control unit 301 based on the count values N2a, N2b, and N2c stored in the count value storage unit 622 (622a to 622c). A stepwise determination is made on the degree of sex (step S606). The determination unit 623 outputs the abnormality determination signal Js2 and inputs the abnormality determination signal Js2 to the inspection device 50 or the storage inspection device 70 (step S607), and displays a stepwise determination result on the display unit.

  As in the fourth embodiment, when the degree of possibility of the confirmed abnormality is determined in three stages of levels “A” to “C”, for example, when the determination result is level “C”, By exchanging parts related to the abnormality, it is possible to prevent a vehicle equipped with a defective electric power steering apparatus from being shipped to the market. In addition, the safety and comfort of the vehicle can be improved by exchanging parts while the electric power steering apparatus is in a safe state.

  In the fourth embodiment, the number of abnormality diagnosing means is not limited to three, but the number of abnormality diagnosing means corresponding to each part of the electric power steering apparatus and sensor that need to perform abnormality diagnosis is provided. You may do it. In the above example, (a) at the time of manufacture of the control unit (electric power steering device), (b) at the time of inspection of the production line of the electric power steering device, and (c) at the stage of mounting the electric power steering device on the vehicle. In this initial diagnosis or normal diagnosis, abnormality diagnosis is performed, but the number of abnormality diagnosis is not limited to three, and may be performed in another arbitrary process.

  Further, in the fourth embodiment, when the abnormality diagnosis means makes a step-by-step determination on the degree of possibility of occurrence of the abnormality determined in each part of the electric power steering device, the count value in the plurality of abnormality diagnosis is calculated. Although stepwise determination is performed based on the total value, stepwise determination may be performed using individual determination criteria for each count value in each abnormality diagnosis.

  Even for products for which it is determined that there is no high probability of occurrence of a confirmed abnormality in each abnormality diagnosis, (a) during manufacturing, (b) during production line inspection, and (c) during the assist operation, three abnormality diagnosis If the determination is made based on the total number of times that an indefinite abnormality has been detected, there is a possibility that it is determined that there is a high possibility that a confirmed abnormality will occur. In the fourth embodiment, in order not to ship such products to the market, (a) at the time of manufacture, (b) at the time of inspection of the production line, and (c) at the time of assist operation, etc. Based on the count value of the number of times an uncertain abnormality is detected in the abnormality diagnosis, a stepwise determination is made as to the degree of possibility that a confirmed abnormality will occur.

  As mentioned above, although embodiment of this invention was described concretely, this invention is not limited to this, In the range which does not deviate from the meaning, it can change suitably.

DESCRIPTION OF SYMBOLS 10 Torque sensor 20 Motor 30, 30A-30D Control unit 301 Motor drive control part 50 Inspection apparatus 54, 71 Display part 56 Input / output IF part 57 Power supply part 61A, 61B, 62A-62C, 63A, 63B Abnormality diagnosis means 611, 621 Abnormality detection unit 612, 622 Count value storage unit 613, 623 Judgment unit 70 Memory inspection device

Claims (2)

In an electric power steering apparatus comprising: a control unit that drives and controls a motor that applies assist torque to a steering mechanism of a vehicle; and a plurality of abnormality diagnosis units that diagnose abnormality of each unit.
The abnormality diagnosing means detects an indefinite abnormality that does not result in confirmation of each part, and in the abnormality diagnosis performed at the time of manufacturing line inspection, a count value a that is the number of times the uncertain abnormality is detected in the abnormality diagnosis at the time of manufacturing. The count value b, which is the number of times that the indefinite abnormality is detected, and the count value c, which is the number of times that the indeterminate abnormality is detected in the abnormality diagnosis performed during the assist operation at the stage of being mounted on the vehicle, are stored. An electric power steering apparatus comprising a function of stepwise determining a degree of possibility of occurrence of a confirmed abnormality in each part based on the value a, the count value b, and the count value c. The electric power steering apparatus according to claim 1 , further comprising a function of notifying a driver of a result of the stepwise determination.

Images