JP2013258628A - Information processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information processing device that can discriminate a temporary anomaly from a permanent anomaly in an AD converter.SOLUTION: A microcontroller 1 has a self-diagnostic power generator 17 capable of generating a reference voltage, and the function of storing an AD conversion result by an AD converter 10 of the reference voltage generated by the self-diagnostic power generator 17 and an AD conversion result by the AD converter 10 of an externally input analog value in respective predetermined areas of an AD conversion result storage register 16. The microcontroller 1 can function as anomaly detection means for reading out the AD conversion result of the reference voltage from the AD conversion result storage register 16 and checking whether or not the AD conversion result is within a corresponding effective range to detect an anomaly in the AD converter 10. The microcontroller 1 functions as anomaly discrimination means for measuring the frequency of anomaly detection in the AD converter 10 and discriminating a temporary anomaly from a permanent anomaly in the AD converter 10 in accordance with the frequency.

Description

  The present invention relates to an information processing apparatus, and more particularly to an information processing apparatus capable of controlling a control target.

  Conventionally, an information processing apparatus including a microcontroller that controls a control target is known. The microcontroller converts a plurality of input analog values into digital values, that is, AD conversion, and controls a control target based on the digital values. When the information processing apparatus is used, various abnormalities can occur in the microcontroller. Regarding an abnormality of a microcontroller, in an AD converter having a plurality of AD conversion channels for one AD conversion unit, for example, due to an abnormality of a multiplexer, switching of channels to be selected is not normally performed, and digital outputs of all channels are fixed. There is an abnormality to do. Such an abnormality may affect the system particularly in a product related to safety such as an electric power steering system, and it is necessary to detect the abnormality in real time and take some measures.

JP 2009-284302 A

  In response to the above request, conventionally, the effective range of two or more inputs of analog inputs given from the outside is set not to overlap, and when the two terminals of the analog input are short-circuited or the bit of the digital output is fixed, Since a deviation occurs in the effective range of any one of the channels, there has been proposed a method for detecting an abnormality by a method of detecting this. However, this method has a problem that the design of a free circuit is remarkably hindered because the range of analog input given from the outside is limited. In addition, when the effective range of analog values cannot be separated on the circuit, it is necessary to provide a dedicated input only for detecting the abnormality of the AD converter, so dedicated hardware must be provided on the circuit. There was a problem that the manufacturing cost increased.

On the other hand, in recent years, a microcontroller has been proposed in which a reference voltage generation circuit is provided inside the microcontroller and the abnormality of the AD converter can be detected without external input (see, for example, Patent Document 1). In this microcontroller, the analog reference voltage generated by the self-diagnosis power supply generator is stored in a reference voltage conversion result holding register ADRD, which is a region different from the analog input outside the microcontroller.
However, this microcontroller does not discriminate between a temporary abnormality and a permanent abnormality of the AD converter. For example, the voltage input to the microcontroller fluctuates in an analog manner so that the power supply generator for self-diagnosis There is a problem that the system is stopped even when no permanent abnormality actually occurs in the AD converter.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide an information processing apparatus capable of discriminating between a temporary abnormality and a permanent abnormality of an AD converter.

  The present invention includes a microcontroller, an abnormality detection unit, and an abnormality determination unit. The microcontroller includes a register, an AD converter that converts an analog value input from a plurality of AD channels into a digital value, a reference voltage generation unit that can generate a reference voltage, and the like. Further, the microcontroller stores the AD conversion result of the reference voltage generated by the reference voltage generation means by the AD converter and the AD conversion result of the analog value AD converter input from the outside in a predetermined area of the register, respectively. It has a function to do. The abnormality detection means can detect an abnormality of the AD converter by reading the AD conversion result of the reference voltage from the register and confirming whether or not the AD conversion result is within the corresponding effective range. The abnormality determination unit measures the number of times that the abnormality of the AD converter is detected by the abnormality detection unit, and determines a temporary abnormality and a permanent abnormality of the AD converter according to the number of times. As described above, according to the present invention, it is possible to discriminate between a temporary abnormality and a permanent abnormality of the AD converter by the abnormality determination means.

  According to the present invention, in a microcontroller having a means for generating a reference voltage therein, a check result for the reference voltage is counted for a certain period of time, and the AD converter becomes a permanent abnormality only when it is in an abnormal state for a certain number of times. By discriminating that the problem has occurred, the above-mentioned problems of the prior art are solved.

(A) is a schematic diagram which shows the state which applied the information processing apparatus by 1st Embodiment of this invention to the electric power steering system, (B) is a schematic diagram which shows the microcontroller of information processing apparatus. The flowchart which shows the abnormality detection of the information processing apparatus by 1st Embodiment of this invention, and abnormality determination processing. The flowchart which shows the abnormality detection of the information processing apparatus by 2nd Embodiment of this invention, and abnormality determination processing.

Hereinafter, control devices according to a plurality of embodiments of the present invention will be described with reference to the drawings. Note that, in a plurality of embodiments, substantially the same components are denoted by the same reference numerals, and description thereof is omitted.
(First embodiment)

  An information processing apparatus according to the first embodiment of the present invention is shown in FIG. An electronic control unit (hereinafter referred to as “ECU”) 2 as an information processing device processes information input from the outside, and drives and controls a motor 4 as a control target based on the processed information. The ECU 2 is employed together with the motor 4 in, for example, an electric power steering system 90 for assisting the steering operation of the vehicle. Here, the electric power steering system 90 corresponds to a “system” in the claims.

FIG. 1A shows the overall configuration of the electric power steering system 90. In the electric power steering system 90, a torque sensor 94 is provided on a steering shaft 92 connected to a handle 91. The torque sensor 94 detects a steering torque input to the steering shaft 92 from the driver via the handle 91.
A pinion gear 96 is provided at the tip of the steering shaft 92, and the pinion gear 96 meshes with the rack shaft 97. A pair of wheels 98 are rotatably connected to both ends of the rack shaft 97 via tie rods or the like.

As a result, when the driver rotates the handle 91, the steering shaft 92 connected to the handle 91 rotates, and the rotational motion of the steering shaft 92 is converted into the linear motion of the rack shaft 97 by the pinion gear 96. The pair of wheels 98 are steered at an angle corresponding to 97 linear motion displacement.
The electric power steering system 90 includes a motor 4 that generates a steering assist torque, an ECU 2 that drives and controls the motor 4, a reduction gear 93 that reduces the rotation of the motor 4 and transmits the rotation to the steering shaft 92, and the like. The motor 4 is, for example, a three-phase drive type brushless DC motor. The motor 4 is driven by being supplied with power from a battery 5 as a power source. The motor 4 rotates the reduction gear 93 forward and backward. The electric power steering system 90 includes the torque sensor 94 described above.
With this configuration, the electric power steering system 90 generates a steering assist torque for assisting the steering of the handle 91 from the motor 4 based on a signal from the torque sensor 94 and the like, and transmits the steering assist torque to the steering shaft 92.

Next, the ECU 2 will be described with reference to FIG. The ECU 2 includes a microcontroller 1 and an inverter 3.
FIG. 1B is a configuration diagram of the microcontroller 1. The microcontroller 1 is a microcontroller (microcomputer) that generates a digital signal or samples an analog input signal, and is used for various purposes such as motor control in the electric power steering system 90. In the present embodiment, the microcontroller 1 is used for the purpose of driving and controlling the motor 4.

  The microcontroller 1 includes a plurality of ANr to ANs such as the steering torque signal, the motor rotation angle that is the rotation angle of the motor 4, the inverter voltage that is the voltage of the inverter 3, and the battery voltage that is the voltage of the battery 5. There is an analog input (AD channel), which is converted from an analog value to a digital value by the AD converter 10, that is, AD conversion. The microcontroller 1 generates a command value for the inverter 3 based on the converted digital value (AD conversion result). The inverter 3 converts electric power from the battery 5 based on the command value and supplies it to the motor 4. Thereby, the motor 4 is rotationally driven.

The CPU 11 is a central processing unit (CPU) that performs calculations in the microcontroller 1. The RAM 12 is a random access memory (RAM) that stores a calculation result by the CPU 11. These are connected by a bus 13.
The AD converter 10 also includes an analog multiplexer 14 that selects analog inputs to a plurality of AD channels, an AD conversion circuit 15 that digitally converts input values, and an AD conversion result storage register that stores AD conversion results. 16 etc. Further, the AD converter 10 includes a self-diagnosis power supply generator 17 as a reference voltage generation unit.

  A power supply Vcc for peripheral devices (for example, 5 V) is input to the self-diagnosis power generator 17. The self-diagnosis power generator 17 includes a plurality of reference voltage values having different effective ranges (for example, a power supply for peripheral devices (Vcc: 5 V) × 0 (0 V), a power supply for peripheral devices (Vcc : 5V) × 1/2 (2.5V), power supply for peripheral devices (Vcc: 5V) × 1 (5V), etc.) can be periodically switched and generated. At this time, the AD conversion result storage register 16 includes a plurality of AD conversion results of analog values (applied voltages) ANr to ANs input from the outside of the microcontroller 1 and the self-diagnosis power generator 17 internally generated. The AD conversion result of the reference voltage (0 to 5 V: analog value) can be stored in different areas.

  Using the microcontroller 1 as described above, it is possible to detect an abnormality of the analog multiplexer 14 by confirming by software whether or not the reference voltage generated from the power supply generator 17 for self-diagnosis is within an appropriate range. Is possible. For example, among the reference voltages generated from the power supply generator 17 for self-diagnosis, the power supply for peripheral devices (Vcc: 5 V) × 0 (0 V) is larger than a certain threshold (for example, 1 V), or the peripheral devices When the power supply (Vcc: 5 V) × 1 (5 V) is smaller than a certain threshold (for example, 4 V), it can be determined that the analog multiplexer 14 is abnormal.

However, in a system that periodically performs AD conversion such as the electric power steering system 90, even if an abnormality occurs once, if the correct data is overwritten in the next period, the system will not be significantly affected. There are also many. If there is a temporary abnormality that does not actually cause an abnormality in the AD conversion circuit, such as when the voltage input to the microcontroller 1 fluctuates in an analog manner, the normal state is restored at the next AD conversion.
However, when a permanent abnormality such as an abnormal mode in which AD values (AD conversion results) of all the channels are fixed (fixed to a certain value) is reached, early measures such as system stop are required.
Therefore, in the present embodiment, when an abnormality occurs, it is not immediately determined as a permanent abnormality, and a temporary abnormality (hereinafter, referred to as a permanent abnormality) is performed by performing a permanent abnormality treatment only when the abnormal state continues. As appropriate, it is possible to distinguish between “temporary abnormality”) and permanent abnormality (hereinafter, appropriately referred to as “permanent abnormality”).

A processing flow related to abnormality detection and abnormality determination by the microcontroller 1 of this embodiment is shown in FIG.
In the processing flow S100, first, in S101, the AD conversion result of the reference voltage generated from the self-diagnosis power generator 17 built in the microcontroller 1 is acquired from the AD conversion result storage register 16. After that, in S102, the microcontroller 1 functions as “abnormality detection means” in the claims to confirm whether the AD conversion result of the acquired reference voltage is within the corresponding effective range.

  When the AD conversion result of the generated reference voltage is within the valid range (S102: YES), normal operation is performed in S103. On the other hand, if it is out of range (S102: NO), an abnormality counter provided on the RAM 12 is added in S104. When this abnormality counter is smaller than a certain threshold value (S105: YES), it is determined that the AD converter 10 is temporarily abnormal, and in S106, a measure for the temporary abnormality is performed. Further, when the threshold value is exceeded (S105: NO), it is determined that there is a permanent abnormality for the first time, and a treatment for the permanent abnormality is performed in S107.

  As described above, the microcontroller 1 functions as the “abnormality determination unit” in the claims so that it can discriminate between a temporary abnormality and a permanent abnormality of the AD converter 10 (analog multiplexer 14). For example, in the case of a temporary abnormality, the previously used AD conversion value is used in place of the AD conversion value (AD conversion result) acquired this time, thereby avoiding a significant influence on the system while avoiding a significant influence on the system. Drive control can be continued. Of course, if the system permits, the drive control of the motor 4 may be continued using the AD conversion value acquired this time. Here, the microcontroller 1 functions as “control continuation means” in the claims. On the other hand, when it is determined that there is a permanent abnormality, it is possible to take a measure of stopping the drive control of the motor 4. Here, the microcontroller 1 functions as “control stop means” in the claims.

  As described above, in this embodiment, the microcontroller 1 generates the AD conversion result storage register 16, the AD converter 10 that converts analog values input from a plurality of AD channels into digital values, and the reference voltage. A possible self-diagnosis power generator 17 is included. Further, the microcontroller 1 converts the AD conversion result by the AD converter 10 of the reference voltage generated by the power supply generator 17 for self-diagnosis and the AD conversion result by the AD converter 10 of the analog value input from the outside into the AD. It has a function of storing in a predetermined area of the conversion result storage register 16. Further, the microcontroller 1 functions as an abnormality detection means, reads the AD conversion result of the reference voltage from the AD conversion result storage register 16, and confirms whether or not the AD conversion result is within the corresponding effective range. Thus, the abnormality of the AD converter 10 can be detected. Furthermore, the microcontroller 1 functions as an abnormality determination unit, measures the number of times that the abnormality of the AD converter 10 is detected, and determines whether the AD converter 10 is temporarily or permanently abnormal according to the number of times. To do. As described above, in the present embodiment, the microcontroller 1 functioning as an abnormality determination unit can determine a temporary abnormality and a permanent abnormality of the AD converter 10.

  In this embodiment, the ECU 2 is applied to an electric power steering system 90 that controls the motor 4 based on an analog value AD conversion result input from the outside of the microcontroller 1. The microcontroller 1 functions as a control continuation unit, and when it is determined that a temporary abnormality has occurred in the microcontroller 1, the drive control of the motor 4 is continued using the AD conversion result obtained normally last time. As a result, when a temporary abnormality that has a small influence on the electric power steering system 90 occurs in the microcontroller 1, the steering assist by the driver can be continued without stopping the electric power steering system 90. it can.

  In the present embodiment, the microcontroller 1 functions as a control stop unit, and stops driving control of the motor 4 when it is determined that a permanent abnormality of the microcontroller 1 has occurred. As a result, when a permanent abnormality having a great influence on the electric power steering system 90 occurs in the microcontroller 1, the electric power steering system 90 is stopped so that the abnormal operation of the electric power steering system 90 can be It is possible to prevent an influence on steering by a person.

By the way, as described above, by monitoring at least one of the reference voltages generated inside the microcontroller 1, it is possible to detect an abnormality in the AD converter 10 (analog multiplexer 14). However, in the abnormality detection using the AD conversion result of one reference voltage, all channels are detected with the AD value within the effective range of the reference voltage of the channel having the effective range overlapping the effective range of the reference voltage due to the abnormality of the analog multiplexer 14 or the like There is a problem that an abnormality cannot be detected when the AD value is fixed.
For example, when the reference voltage (power supply for peripheral devices (Vcc: 5 V) × 1 (5 V)) internally generated by the self-diagnosis power generator 17 is smaller than a certain threshold (for example, 4 V), the analog multiplexer 14 is determined to be abnormal (that is, the effective range of the reference voltage is 4 to 5 V).

  At this time, a channel having an effective range (for example, 0.5 to 4.5 V) overlapping with the effective range of the reference voltage is selected by the analog multiplexer 14, and thereafter, this channel is always selected due to an abnormality of the analog multiplexer 14, etc. When the digital output (AD conversion result) of all channels is fixed at a value (for example, 4.2 V) that satisfies the effective range of the reference voltage, the AD conversion result of the reference voltage that is an abnormal output is the effective of the reference voltage. Because it falls within the range, it is impossible to detect anomalies by monitoring the reference voltage.

(Second Embodiment)
An ECU according to a second embodiment of the present invention will be described with reference to FIG. Although the second embodiment has the same physical configuration as that of the first embodiment, processing relating to abnormality detection is different from that of the first embodiment.

  The second embodiment has been made in view of the above-described problem of the first embodiment. In the microcontroller 1 having a circuit (self-diagnosis power generator 17) for generating a reference voltage having a different effective range inside. In addition to periodically switching a plurality of reference voltages having different effective ranges among the reference voltages, by using the plurality of reference voltages, it is possible to improve the detection coverage of the abnormality of the multiplexer 14 by monitoring the reference voltages.

FIG. 3 shows an operation flow S200 of abnormality detection using a plurality of reference voltages.
In the present embodiment, first, in S201, the self-diagnosis power generator 17 in the microcontroller 1 periodically switches and generates a plurality of reference voltage values having different effective ranges. In step S202, the plurality of reference voltage values (analog values) are AD-converted, and AD conversion results (X1, X2,...) Are stored in a predetermined area of the AD conversion result storage register 16.
Subsequently, the AD conversion value (AD conversion result) of the reference voltage (analog value) generated from the self-diagnosis power supply generator 17 built in the microcontroller 1 by DMAC (Direct Memory Access Controller) or the like is not limited thereto. Transfer and store from the AD conversion result storage register 16 to the RAM 12.

Next, in S203, AD conversion results (X1, X2,...) Of a plurality of reference voltages stored in the RAM 12 are acquired. In S204, AD conversion results (X1, X2,. ..) Are within the effective range corresponding to each reference voltage.
If the generated AD conversion results of the plurality of reference voltages are all within the valid range (S204: YES), normal operation is performed in S205. On the other hand, if either is out of range (S204: NO), an abnormal counter provided on the RAM 12 is added in S206. When this abnormality counter is smaller than a certain threshold value (S207: YES), it is determined that the AD converter 10 (analog multiplexer 14) is temporarily abnormal, and a temporary abnormality treatment is performed in S208. On the other hand, when the threshold value is exceeded (S207: NO), it is determined that there is a permanent abnormality for the first time, and a treatment for the permanent abnormality is performed in S209.

  In this way, by using a plurality of reference voltage values having different effective ranges for abnormality detection, digital output values (AD conversion results) of all channels with AD conversion values (AD conversion results) satisfying the effective range of one reference voltage. Even when the signal is fixed, it is possible to detect an abnormality of the AD converter 10 (analog multiplexer 14) by deviating from the effective range of any reference voltage value.

  As described above, in the present embodiment, the self-diagnosis power generator 17 can generate a plurality of reference voltages having different effective ranges. Further, the microcontroller 1 functions as an abnormality detection unit, and confirms whether the AD conversion results of a plurality of reference voltages having different effective ranges are within the corresponding effective ranges, thereby detecting the abnormality of the AD converter 10. Can be detected. As a result, even if an abnormality occurs in which the digital output values (AD conversion results) of all the channels are fixed with an AD conversion value (AD conversion result) that satisfies the effective range of one reference voltage, the microcontroller 1 detects the abnormality. can do.

(Other embodiments)
In the second embodiment described above, a plurality of reference voltage values are AD-converted in S202, the AD conversion results (X1, X2,...) Are stored in a predetermined area of the AD conversion result storage register 16, and then the DMAC 18 An example is shown in which the AD conversion result is transferred to the RAM 12 and the AD conversion result (X1, X2,...) In the RAM 12 is confirmed in S203. In contrast, in another embodiment of the present invention, a plurality of reference voltage values are AD-converted in S202, and AD conversion results (X1, X2,...) Are stored in a predetermined area of the AD conversion result storage register 16. After that, the AD conversion results (X1, X2,...) In the AD conversion result storage register 16 may be confirmed in S203. It should be noted that the AD conversion results (X1, X2,...) May be confirmed one by one instead of collectively.

The information processing apparatus according to the present invention may control a motor other than the motor used in the electric power steering system. For example, a motor used in a gear ratio variable device or a steering device of a steer-by-wire system may be controlled. Moreover, it is good also considering not only the motor used for a vehicle-mounted system but all apparatuses driven by electric power, such as a motor used for an air compressor.
Thus, the present invention is not limited to the above-described embodiments, and can be applied to various forms without departing from the gist thereof.

1... Microcontroller (abnormality detection means, abnormality determination means)
2 ··· ECU (information processing device)
10: AD converter 16: AD conversion result storage register (register)
17... Self-diagnosis power generator (reference voltage generating means)

Claims (6)

A register (16), an AD converter (10) for converting an analog value input from a plurality of AD channels into a digital value, a reference voltage generating means (17) capable of generating a reference voltage, and the reference voltage generating means A microcontroller (1) having a function of storing an AD conversion result by the AD converter of the generated reference voltage and an AD conversion result by the AD converter of an analog value inputted from the outside in a predetermined area of the register. )When,
An abnormality detection means (1) capable of detecting an abnormality of the AD converter by reading the AD conversion result of the reference voltage from the register and confirming whether or not the AD conversion result is within a corresponding effective range. When,
An abnormality determining means (1) for measuring the number of times the abnormality of the AD converter is detected by the abnormality detecting means, and determining a temporary abnormality and a permanent abnormality of the AD converter according to the number of times;
An information processing apparatus (2) comprising: A register (16), an AD converter (10) for converting an analog value input from a plurality of AD channels into a digital value, a reference voltage generating means (17) capable of generating a reference voltage, and the reference voltage generating means A microcontroller (1) having a function of storing an AD conversion result by the AD converter of the generated reference voltage and an AD conversion result by the AD converter of an analog value inputted from the outside in a predetermined area of the register. )When,
An abnormality detection means (1) capable of detecting an abnormality of the AD converter by reading the AD conversion result of the reference voltage from the register and confirming whether or not the AD conversion result is within a corresponding effective range. And comprising
The reference voltage generation means can generate a plurality of the reference voltages having different effective ranges,
The abnormality detection means is capable of detecting an abnormality of the AD converter by confirming whether or not the AD conversion results of the plurality of reference voltages having different effective ranges are within the corresponding effective ranges. Characteristic information processing apparatus (2).   An abnormality determining means (1) for measuring the number of times that the abnormality of the AD converter is detected by the abnormality detecting means, and determining a temporary abnormality and a permanent abnormality of the microcontroller according to the number of times. The information processing apparatus according to claim 2. Applied to the system (90) for controlling the control object (4) based on the AD conversion result by the AD converter of the analog value inputted from the outside of the microcontroller;
Control continuation means (1) for continuing control of the controlled object using the AD conversion value result obtained normally last time when it is determined by the abnormality determination means that a temporary abnormality has occurred in the AD converter. The information processing apparatus according to claim 1, further comprising: Applied to the system (90) for controlling the control object (4) based on the AD conversion result by the AD converter of the analog value inputted from the outside of the microcontroller;
Control continuation means (1) for continuing control of the controlled object using the AD conversion value result determined to be abnormal when the abnormality determination means determines that a temporary abnormality of the AD converter has occurred. The information processing apparatus according to claim 1, further comprising: an information processing apparatus according to claim 1. Applied to the system (90) for controlling the control object (4) based on the AD conversion result by the AD converter of the analog value inputted from the outside of the microcontroller;
The control stop means (1) for stopping the control of the control object when the abnormality determination means determines that a permanent abnormality of the AD converter has occurred. The information processing apparatus according to any one of claims.

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