JP2005249780A - Control using multiplex sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a novel technique capable of continuing control even when abnormality is generated in one portion of a plurality of sensors. <P>SOLUTION: When outputs from the two sensors 165a, 165b are respectively within normal output ranges, change patterns of the outputs from the two sensors are investigated to detect the generation of the abnormality in one of the sensors. When the abnormality is detected, a control input is determined using the output from the normal sensor. Alternatively, the control inputs obtained from the outputs from the two sensors 165a, 165b are not used when the substantially consistent control inputs are not obtained from the outputs from the two sensors, and the control inputs obtained from the outputs from the two sensors are used when the substantially matched control inputs are obtained from the outputs from the two sensors. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a control technique using multiple sensors, and more particularly to a control technique when an abnormality occurs in any one of the sensors.

  In order to increase the reliability of the control system, two sensors for giving the same control input may be used. When the two sensors are operating normally, the control inputs obtained from them are almost equal. However, when an abnormality occurs in any one of the sensors, there is a large difference between the two control inputs. In this case, how to control is a big problem.

  Japanese Patent Application Laid-Open No. 9-191501 describes a technique for limiting a sudden increase in torque command value when one of the two accelerator sensors for a vehicle exceeds the upper and lower limits of a normal output range.

  Japanese Patent Application Laid-Open No. 10-77889 discloses that even when an abnormality occurs in one of the two accelerator sensors, if the changes in the two accelerator sensors are substantially the same, the change is indicated by the driver. A technique for performing control of the throttle valve based on the determination is disclosed.

  In the technique disclosed in Japanese Patent Laid-Open No. 9-158765, two sensors are used in which the sensor output and the amount of movement of the accelerator pedal are inversely proportional. Such a sensor has a characteristic that the output of the abnormal sensor is smaller than the output of the normal sensor when both of the outputs are within the normal range. Even if the output of the output is within the range of the normal output, it is described that the larger output can be determined to be normal if the difference between the outputs of the both is equal to or greater than a predetermined value (gazette) Paragraph 0008).

  However, in the technique described in Japanese Patent Application Laid-Open No. 9-191501, when both outputs of the two accelerator sensors are in a normal output range, it is impossible to detect which one is abnormal, and accordingly It is impossible to continue control. Further, with the technique described in Japanese Patent Application Laid-Open No. 10-77889, it is impossible to continue the control except when the changes of the two sensors are substantially the same. Further, the technique described in Japanese Patent Laid-Open No. 9-158765 can be applied only when a sensor with special characteristics is used. That is, conventionally, except when a sensor with special characteristics is used, even if an abnormality occurs in one of the sensors, if the output is within the normal output range, it is determined which is abnormal. It was difficult to do. For this reason, conventionally, when an abnormality occurs in one of the two sensors within the normal output range, there is a problem that the control input from those sensors cannot be used. Such a problem is not limited to the accelerator sensor, but is a problem common when two or more sensors are used to provide the same control input.

  The present invention has been made to solve the above-described conventional problems, and provides a new technique that enables control to be continued even when an abnormality occurs in a part of a plurality of sensors. With the goal

  In order to achieve the above object, in the first configuration of the present invention, when the outputs of the first and second sensors giving the same control input are within the normal output range, the first and second It is detected that an abnormality has occurred in one of the first sensor and the second sensor by examining the change pattern of the output of the sensor. Then, when an abnormal sensor is detected, the control input is determined using the output of a sensor other than the abnormal sensor.

  In the above configuration, since the abnormal sensor is detected by examining the change pattern of the output of the first and second sensors, the output of the first and second sensors is also within the normal output range. It is possible to detect the abnormality. Further, since the control input is determined using a sensor that is not an abnormal sensor, it is possible to continue control even when an abnormality occurs in some sensors.

  In the above configuration, the abnormality sensor may be detected by checking whether or not the change pattern of the output of each sensor corresponds to any of a plurality of abnormality patterns set in advance.

  In this configuration, it is possible to detect a sensor abnormality more reliably by setting in advance an abnormal pattern that is likely to occur.

  The plurality of abnormal patterns include a sensor output step change, a sensor output vibration, a difference in the difference between the first and second sensor outputs, and a fixed sensor output that cannot be obtained when the sensor is normal. Preferably, at least one of the states is included.

  Since such a pattern is likely to occur when the sensor is abnormal, it is possible to easily detect the abnormality by setting it as an abnormal pattern in advance.

  Note that a control device that performs such control preferably includes an abnormality history registration unit that registers an abnormality occurrence history indicating an abnormality pattern that has occurred.

  In this configuration, it is possible to know what kind of abnormality has occurred by checking the abnormality history registration unit later.

  In addition, when determining the control input using a sensor other than the abnormal sensor, a determination method is employed in which the value of the control input is smaller than when both the first and second sensors are normal. The control input may be determined from the output of the sensor.

  In this way, more conservative control can be performed when an abnormality occurs in the sensor.

  When one of the outputs of the first and second sensors suddenly changes at a rate of change equal to or greater than a predetermined threshold, it is determined by the abnormality detection unit whether or not there is an abnormality from the time when the output suddenly changes. The control input may be determined using the output of a sensor other than the sensor whose output has suddenly changed during the provisional period up to the point in time. Alternatively, during this provisional period, a smaller value of the two control inputs obtained from the outputs of the first and second sensors may be adopted as the control input.

  With these configurations, more conservative control can be executed even during the provisional period.

  In the second configuration of the present invention, when at least one of the outputs of the first and second sensors for giving the same control input is abnormal, the outputs of the first and second sensors substantially coincide with each other. When the control input cannot be obtained, the control input obtained from the outputs of the first and second sensors is not used, while the substantially identical control input is obtained from the outputs of both the first and second sensors. Control is performed using the control input obtained from the outputs of the first and second sensors.

  In this way, even when an abnormality occurs in either the first sensor or the second sensor, control is performed by using the control input that is substantially the same when both of them are obtained, so the control is continued. It is possible.

  For example, the first sensor is an analog sensor that outputs an analog output signal indicating a vehicle shift position, and the second sensor is a plurality of switches that output a plurality of switch signals indicating a vehicle shift position. It is a switch type sensor constituted.

  In such a configuration, since the shift position is used when a coincident shift position is obtained from the two sensors, it is possible to continue control of the vehicle even if an abnormality occurs in the shift position sensor.

  Note that the present invention can be realized in various modes, for example, a multiple sensor abnormality detection device and detection method, a control device and control method using the multiple sensor, a moving body using the control device, The present invention can be realized in the form of a computer program for realizing the function of the control device or the control method, a recording medium recording the computer program, a data signal including the computer program and embodied in a carrier wave, and the like.

Next, embodiments of the present invention will be described in the following order based on examples.
A. B. Overall configuration of hybrid vehicle B. Basic operation of hybrid vehicle Configuration of control system Abnormal detection of accelerator sensor Abnormality detection of shift position sensor Modified example

A. Overall configuration of hybrid vehicle:
FIG. 1 is an explanatory diagram showing the overall configuration of a hybrid vehicle as one embodiment of the present invention. This hybrid vehicle includes three prime movers, that is, an engine 150 and two motor / generators MG1 and MG2. Here, “motor / generator” means a prime mover that functions as a motor and also functions as a generator. In the following, for simplicity, these are simply referred to as “motors”. Control of the vehicle is performed by the control system 200.

  The control system 200 includes a main ECU 210, a brake ECU 220, a battery ECU 230, and an engine ECU 240. Each ECU is configured as one unit in which a plurality of circuit elements such as a microcomputer, an input interface, and an output interface are arranged on one circuit board. The main ECU 210 has a motor control unit 260 and a master control unit 270. The master control unit 270 has a function of determining a control amount such as distribution of outputs of the three prime movers 150, MG1, and MG2.

  The engine 150 is a normal gasoline engine, and rotates the crankshaft 156. The operation of engine 150 is controlled by engine ECU 240. Engine ECU 240 executes control of the fuel injection amount of engine 150 and other controls in accordance with instructions from master control unit 270.

  Motors MG1 and MG2 are configured as synchronous motors, and stators 133 and 143 around which rotors 132 and 142 having a plurality of permanent magnets on the outer peripheral surface and three-phase coils 131 and 141 that form a rotating magnetic field are wound. With. The stators 133 and 143 are fixed to the case 119. Three-phase coils 131 and 141 wound around stators 133 and 143 of motors MG1 and MG2 are connected to secondary battery 194 via drive circuits 191 and 192, respectively. The drive circuits 191 and 192 are transistor inverters each including a pair of transistors as switching elements for each phase. The drive circuits 191 and 192 are controlled by the motor control unit 260. When the transistors of drive circuits 191 and 192 are switched by a control signal from motor control unit 260, a current flows between battery 194 and motors MG1 and MG2. The motors MG1 and MG2 can operate as electric motors that are driven to rotate by receiving power supplied from the battery 194 (hereinafter, this operation state is referred to as power running), and the rotors 132 and 142 are rotated by external force. Can function as a generator that generates electromotive force at both ends of the three-phase coils 131 and 141 to charge the battery 194 (hereinafter, this operation state is referred to as regeneration).

  The rotation shafts of engine 150 and motors MG1 and MG2 are mechanically coupled via planetary gear 120. The planetary gear 120 includes a sun gear 121, a ring gear 122, and a planetary carrier 124 having a planetary pinion gear 123. In the hybrid vehicle of this embodiment, the crankshaft 156 of the engine 150 is coupled to the planetary carrier shaft 127 via the damper 130. The damper 130 is provided to absorb torsional vibration generated in the crankshaft 156. Rotor 132 of motor MG1 is coupled to sun gear shaft 125. The rotor 142 of the motor MG2 is coupled to the ring gear shaft 126. The rotation of the ring gear 122 is transmitted to the axle 112 and the wheels 116R and 116L via the chain belt 129 and the differential gear 114.

  The control system 200 uses various sensors to realize control of the entire vehicle. For example, an accelerator sensor 165 for detecting the amount of depression of the accelerator by the driver, a shift position sensor for detecting the position of the shift lever. 167, a brake sensor 163 for detecting the depression pressure of the brake, a battery sensor 196 for detecting the charging state of the battery 194, a rotation speed sensor 144 for measuring the rotation speed of the motor MG2, and the like are used. Since the ring gear shaft 126 and the axle 112 are mechanically coupled by the chain belt 129, the ratio of the rotational speeds of the ring gear shaft 126 and the axle 112 is constant. Therefore, the rotation speed sensor 144 provided on the ring gear shaft 126 can detect not only the rotation speed of the motor MG2 but also the rotation speed of the axle 112.

B. Basic operation of a hybrid vehicle:
In order to describe the basic operation of the hybrid vehicle, first, the operation of the planetary gear 120 will be described first. Planetary gear 120 has the property that when the rotational speeds of two of the three rotational shafts described above are determined, the rotational speeds of the remaining rotational shafts are determined. The relationship between the rotational speeds of the respective rotary shafts is as shown in the following equation (1).

  Nc = Ns × ρ / (1 + ρ) + Nr × 1 / (1 + ρ) (1)

  Here, Nc is the rotational speed of the planetary carrier shaft 127, Ns is the rotational speed of the sun gear shaft 125, and Nr is the rotational speed of the ring gear shaft 126. Further, ρ is a gear ratio between the sun gear 121 and the ring gear 122 as represented by the following equation.

  ρ = [number of teeth of sun gear 121] / [number of teeth of ring gear 122]

  Further, the torques of the three rotary shafts have a certain relationship given by the following equations (2) and (3) regardless of the rotational speed.

Ts = Tc × ρ / (1 + ρ) (2)
Tr = Tc × 1 / (1 + ρ) = Ts / ρ (3)

  Here, Tc is the torque of the planetary carrier shaft 127, Ts is the torque of the sun gear shaft 125, and Tr is the torque of the ring gear shaft 126.

  The hybrid vehicle of this embodiment can travel in various states by such a function of the planetary gear 120. For example, in a relatively low speed state where the hybrid vehicle has started to travel, the motor MG2 is powered while the engine 150 is stopped to travel by transmitting power to the axle 112. Similarly, the engine 150 may travel while idling.

  When the hybrid vehicle reaches a predetermined speed after the start of traveling, the control system 200 starts the motor 150 by motoring the motor MG1 with torque output. At this time, the reaction torque of the motor MG1 is also output to the ring gear 122 via the planetary gear 120.

  When the engine 150 is operated and the planetary carrier shaft 127 is rotated, the sun gear shaft 125 and the ring gear shaft 126 are rotated under the conditions satisfying the above expressions (1) to (3). The power generated by the rotation of the ring gear shaft 126 is directly transmitted to the wheels 116R and 116L. The power generated by the rotation of the sun gear shaft 125 can be regenerated as electric power by the first motor MG1. On the other hand, if the second motor MG2 is powered, power can be output to the wheels 116R and 116L via the ring gear shaft 126.

  During steady operation, the output of the engine 150 is set to a value approximately equal to the required power of the axle 112 (that is, the rotational speed of the axle 112 × torque). At this time, a part of the output of the engine 150 is directly transmitted to the axle 112 via the ring gear shaft 126, and the remaining output is regenerated as electric power by the first motor MG1. The regenerated electric power is used for generating torque that causes the second motor MG2 to rotate the ring gear shaft 126. As a result, it is possible to drive the axle 112 at a desired rotational speed and with a desired torque.

  When the torque transmitted to the axle 112 is insufficient, the torque is assisted by the second motor MG2. As the electric power for the assist, electric power regenerated by the first motor MG1 and electric power stored in the battery 149 are used. Thus, the control system 200 controls the operation of the two motors MG1 and MG2 according to the required power to be output from the axle 112.

  The hybrid vehicle of this embodiment can also move backward while the engine 150 is operated. When the engine 150 is operated, the planetary carrier shaft 127 rotates in the same direction as when moving forward. At this time, if the sun gear shaft 125 is rotated at a rotational speed higher than the rotational speed of the planetary carrier shaft 127 by controlling the first motor MG1, the ring gear shaft 126 moves in the reverse direction as is apparent from the above equation (1). Invert. The control system 200 can reverse the hybrid vehicle by controlling the output torque while rotating the second motor MG2 in the reverse direction.

  The planetary gear 120 can rotate the planetary carrier 124 and the sun gear 121 while the ring gear 122 is stopped. Therefore, the engine 150 can be operated even when the vehicle is stopped. For example, if the remaining capacity of the battery 194 decreases, the battery 194 can be charged by operating the engine 150 and regenerating the first motor MG1. If the first motor MG1 is powered while the vehicle is stopped, the engine 150 can be motored by the torque and started.

C. Control system configuration:
FIG. 2 is a block diagram illustrating a more detailed configuration of the control system 200 in the embodiment. The master control unit 270 includes a master control CPU 272 and a power supply control circuit 274. The motor control unit 260 includes a motor main control CPU 262 and two motor control CPUs 264 and 266 for controlling the two motors MG1 and MG2, respectively. Each CPU includes a CPU, a ROM, a RAM, an input port, and an output port (not shown), and constitutes a one-chip microcomputer together with these.

  The master control CPU 272 determines control amounts such as the number of rotations and torque distribution of the three prime movers 150, MG1, and MG2, supplies various required values to other CPUs and ECUs, and controls the drive of each prime mover. It has a function. For this control, the master control CPU 272 is supplied with accelerator position signals AP1 and AP2 indicating the accelerator opening, shift position signals SP1 and SP2 indicating the shift position, and the like. The accelerator sensor 165 and the shift position sensor 167 are duplicated, and supply two accelerator position signals AP1 and AP2 and two shift position signals SP1 and SP2 to the master control CPU 272, respectively.

  The power supply control circuit 274 is a circuit for converting the high voltage DC voltage of the battery 194 into a low voltage DC voltage for each circuit in the main ECU 210. The power supply control circuit 274 also has a function as a monitoring circuit that monitors the abnormality of the master control CPU 272.

  The engine ECU 240 controls the engine 150 according to the engine output request value PEreq given from the master control CPU 272. The engine ECU 240 feeds back the rotational speed REVen of the engine 150 to the master control CPU 272.

  The motor main control CPU 262 supplies the current request values I1req and I2req to the two motor control CPUs 264 and 266 in accordance with the torque request values T1req and T2req related to the motors MG1 and MG2 given from the master control CPU 272, respectively. The motor control CPUs 264 and 266 drive the motors MG1 and MG2 by controlling the drive circuits 191 and 192, respectively, according to the current request values I1req and I2req. The rotation speeds REV1, REV2 of the motors MG1, MG2 are fed back to the motor main control CPU 262 from the rotation speed sensors of the motors MG1, MG2. The motor main control CPU 262 feeds back to the master control CPU 272 the rotational speeds REV1, REV2 of the motors MG1, MG2, the current value IB from the battery 194 to the drive circuits 191, 192, and the like.

  The battery ECU 230 monitors the state of charge SOC of the battery 194 and supplies the requested charging value CHreq of the battery 194 to the master control CPU 272 as necessary. The master control CPU 272 determines the output of each prime mover in consideration of this required value CHreq. That is, when charging is necessary, the engine 150 outputs a power larger than the output necessary for traveling, and a part of the power is distributed to the charging operation by the first motor MG1.

  The brake ECU 220 performs control to balance a hydraulic brake (not shown) and a regenerative brake by the second motor MG2. This is because in this hybrid vehicle, the regenerative operation by the second motor MG2 is performed during braking and the battery 194 is charged. Specifically, the brake ECU 220 inputs the regeneration request value REGreq to the master control CPU 272 based on the brake pressure BP from the brake sensor 163. The master control CPU 272 determines the operation of the motors MG1 and MG2 based on the request value REGreq, and feeds back the regeneration execution value REGprac to the brake ECU 220. The brake ECU 220 controls the brake amount by the hydraulic brake to an appropriate value based on the difference between the regeneration execution value REGprac and the regeneration request value REGreq and the brake pressure BP.

  As described above, the master control CPU 272 determines the outputs of the prime movers 150, MG1, and MG2, and supplies the requested values to the ECU 240 and the CPUs 264 and 266 that are responsible for the respective controls. The ECU 240 and the CPUs 264 and 266 control each prime mover according to the required value. As a result, the hybrid vehicle can travel by outputting appropriate power from the axle 112 in accordance with the traveling state. During braking, the brake ECU 220 and the master control CPU 272 cooperate to control the operation of each prime mover and hydraulic brake. As a result, it is possible to achieve braking that regenerates electric power and does not cause the driver to feel much discomfort.

  The four CPUs 272, 262, 264, 266 monitor each other's abnormality using a so-called watchdog pulse WDP, and when the abnormality occurs in the CPU and the watchdog pulse stops, a reset signal RES is sent to the CPU. It has a function to supply and reset. The abnormality of the master control CPU 272 is also monitored by the power supply control circuit 274.

  The abnormality history registration circuit 280 has an EEPROM 282 for registering an abnormality occurrence history. In the EEPROM 282, the history of occurrence of abnormality of the accelerator sensor 165 and the shift position sensor 167 is registered. In addition, reset signals RES 1 and RES 2 transmitted and received between the master control CPU 272 and the motor main control CPU 262 are input to the input port of the abnormality history registration circuit 280. When these reset signals RES 1 and RES 2 are generated, the abnormality history registration circuit 280 stores them in the internal EEPROM 282.

  Note that the master control CPU 272 and the abnormality history registration circuit 280 can make various requests and notifications with each other via the bidirectional communication wiring 214. A bidirectional communication wiring 212 is also provided between the master control CPU 272 and the motor main control CPU 262.

D. Abnormal detection of accelerator sensor:
FIG. 3 is a block diagram showing a circuit configuration related to processing of the output signal of the accelerator sensor. The accelerator sensor 165 includes two sensors 165a and 165b having different characteristics. As these sensors 165a and 165b, for example, potentiometers can be used. The output signals AP1 and AP2 of the two sensors 165a and 165b are input to the master control CPU 272.

  The master control CPU 272 has a function as an abnormality detection unit 272a and a function as a control input determination unit 272b. The abnormality detection unit 272a detects whether or not an abnormality has occurred in the accelerator sensor 165 or the shift position sensor 167. The control input determination unit 272b normally determines the control input (that is, the accelerator opening and the shift position) from the normal output of the sensor. When an abnormality occurs in the sensor, the control output that is not abnormal is used. Determine the control input. The functions of these units 272a and 272b are realized by the master control CPU 272 executing a program stored in a ROM (not shown).

  When an abnormality occurs in the accelerator sensor 165, the content of the abnormality is registered in the EEPROM 282 in the abnormality history registration circuit 280.

  FIG. 4A is a graph showing the input / output characteristics of the accelerator sensor 165. The horizontal axis is the amount of depression of the accelerator pedal, and the vertical axis is the level of the accelerator position signal. The slopes of the output signals AP1 and AP2 output from the two sensors are the same, but have different offsets. However, the slopes of the two output signals AP1 and AP2 can be set to different values.

  The normal output ranges R1 and R2 of the two sensors are set such that the relationship between the outputs AP1 and AP2 of the two sensors and the accelerator opening (the amount of depression of the accelerator pedal) is uniquely determined. In the example of FIG. 4, the normal output ranges R1 and R2 are set to ranges in which the relationship between the sensor outputs AP1 and AP2 and the accelerator opening is represented by a straight line.

  FIG. 4B shows an example of changes in the accelerator position signal when both of the two sensors are operating normally. When both are operating normally, the control input determination unit 272b (FIG. 3) determines the control input (accelerator opening) from the first output signal AP1. However, it is also possible to determine the accelerator opening from the second output signal AP2.

  The abnormality detection unit 272a (FIG. 2) detects whether an abnormality has occurred in the two accelerator sensors. In the present embodiment, the abnormality detection unit 272a detects the abnormality of the sensor depending on whether the temporal change pattern of the sensor output signals AP1 and AP2 corresponds to one of a plurality of preset abnormality patterns. Detected. 5 to 9 show examples of abnormal events of the accelerator sensor.

  FIG. 5 shows a change in the output signal when the abnormal event # 1 (disconnection of the sensor signal line) occurs in the first accelerator sensor 165a. When the signal line of the first accelerator sensor 165a is disconnected, the output signal AP1 drops sharply, falls below a predetermined disconnection level LB, and deviates from the normal output range R1. The abnormality detection unit 272a sends an abnormal preliminary notification PRE to the control input determination unit 272b indicating that an abnormality may have occurred in the sensor 165a at time t0 when the level of the output signal AP1 becomes equal to or lower than the disconnection level LB. Supply. When the abnormality detection unit 272a further confirms that the level of the output signal AP1 is maintained at the offset F1 or less for a predetermined period Δt1 or more, it determines that an abnormality has occurred in the first sensor 165a (time t1). ). Then, the abnormality detection command DET1 is supplied to the control input determination unit 272b to notify the first sensor 165a that the abnormal event # 1 has occurred. The provisional period for abnormality detection is provided to prevent erroneous detection of abnormality due to temporary fluctuations in output.

  After time t1, the master control CPU 272 determines the accelerator opening using the second sensor 165b operating normally without using the abnormal first sensor 165a. In this way, even if an abnormality occurs in one of the two sensors 165a and 165b, the control of the vehicle can be continued.

  In the abnormal period after time t1, the accelerator opening is not determined using the input / output characteristics of the second sensor 165b as it is, but the value of the accelerator opening is higher than when both sensors are normal. It may be made smaller. For example, a value obtained by multiplying the value of the accelerator opening directly obtained from the output signal AP2 of the second sensor 165b by a predetermined coefficient less than 1 (for example, 0.9) is adopted as the accelerator opening used for actual control. May be. In this way, when one of the sensors is abnormal, even if the output of the remaining sensors suddenly increases, it is possible to moderately increase the acceleration of the vehicle.

  The period from time t0 to t1 is a provisional period until it is finally determined whether or not there is an abnormality. In this provisional period, the control input determination unit 272b may determine the accelerator opening by a method different from the case where the two sensors 165a and 165b are both normal. For example, in the provisional period Δt1, the accelerator opening may be determined using the output signal AP2 of another sensor 165b other than the sensor 165a that may be abnormal. Whether or not each sensor may be abnormal can be determined according to whether or not its output is changing at a change rate equal to or higher than a predetermined threshold value.

  In the example of FIG. 5, the case where an abnormality has occurred in the first sensor 165a has been described. Conversely, the same applies to the case where the first sensor 165a is normal and an abnormality has occurred in the second sensor 165b. To be processed. The same applies to other abnormal events described below. In addition, the method for determining the accelerator opening during the abnormal period and the provisional period described above can be similarly applied to other abnormal events described below.

  FIG. 6 shows a change in the output signal when the abnormal event # 2 (hold) occurs in the first accelerator sensor 165a. Here, “hold” means that the output signal is maintained at a constant value, and means a fixed state of the sensor output that cannot be taken when the sensor is normal. When the accelerator sensor is operating normally, it is extremely difficult for the driver to hold the accelerator pedal at a fixed position so that the output signal is maintained at a constant value. Therefore, when the output signal of the accelerator sensor is maintained at a constant value, it can be determined that an abnormality has occurred in the sensor.

  As in the example of FIG. 6, when a predetermined period Δt2a elapses when one output signal AP1 is maintained at a constant value, the abnormality detection unit 272a supplies the abnormality preliminary notification PRE to the control input determination unit 272b (time t2a ). When the abnormality detection unit 272a confirms that the level of the output signal AP1 further continues for a predetermined period Δt2b, the abnormality detection unit 272a determines that an abnormality has occurred in the first sensor 165a (time t2b). Then, the abnormality detection command DET2 is supplied to the control input determination unit 272b to notify the first sensor 165a that the abnormal event # 2 has occurred.

  The master control CPU 272 determines the accelerator opening using the second sensor 165b operating normally without using the first sensor 165a that is abnormal after time t2. Therefore, even if an abnormality occurs in one of the two sensors 165a and 165b, the vehicle control can be continued.

  This abnormal event # 2 is characterized in that the outputs of the two sensors 165a and 165b are both within the normal output ranges R1 and R2. Such an abnormal event has conventionally been difficult to determine which sensor has an abnormality. In this embodiment, the abnormality detection unit 272a detects whether or not the change pattern of the output signal of the accelerator sensor with time corresponds to a preset abnormal event # 2 (hold) pattern, and detects an abnormality of the sensor. doing. As a result, even when the output of the sensor is within the normal range, it is possible to detect the abnormality.

  FIG. 7 shows a change in the output signal when the abnormal event # 3 (rectangular wave vibration) occurs in the first accelerator sensor 165a. When the accelerator sensor is operating normally, it is extremely difficult for the driver to step on the accelerator pedal so that the output signal changes in a rectangular wave shape. Therefore, when the output signal of the accelerator sensor changes in a rectangular wave shape, it can be determined that an abnormality has occurred in the sensor.

  When one output signal AP1 changes suddenly at a change rate equal to or greater than a predetermined threshold at time t0 in FIG. 7, the abnormality detection unit 272a supplies an abnormal preliminary notification PRE to the control input determination unit 272b. The abnormality detection unit 272a determines that an abnormality has occurred in the first sensor 165a after confirming that the change in the rectangular waveform of the output signal AP1 has continued for a predetermined period Δt3 (time t3). Then, the abnormality detection command DET3 is supplied to the control input determination unit 272b to notify the first sensor 165a that the abnormal event # 3 has occurred.

  The master control CPU 272 determines the accelerator opening using the second sensor 165b that is operating normally without using the first sensor 165a that is abnormal after time t3. Therefore, even if an abnormality occurs in one of the two sensors 165a and 165b, the vehicle control can be continued. This abnormal event # 3 is also an event in which the outputs of the two sensors 165a and 165b are both within the normal output ranges R1 and R2.

  FIG. 8 shows a change in the output signal when an abnormal event # 4 (irregular vibration) occurs in the first accelerator sensor 165a. When the accelerator sensor is operating normally, it is extremely difficult for the driver to step on the accelerator pedal so that the output signal changes irregularly and suddenly. Therefore, when the output signal of the accelerator sensor changes irregularly and suddenly, it can be determined that an abnormality has occurred in the sensor.

  When one output signal AP1 suddenly changes at a change rate equal to or greater than a predetermined threshold at time t0 in FIG. 8, the abnormality detection unit 272a supplies an abnormal preliminary notification PRE to the control input determination unit 272b. The abnormality detection unit 272a determines that an abnormality has occurred in the first sensor 165a after confirming that the irregular sudden change in the output signal AP1 has continued for a predetermined period Δt4 (time t4). Then, the abnormality detection command DET4 is supplied to the control input determination unit 272b to notify the first sensor 165a that the abnormal event # 4 has occurred.

  The master control CPU 272 determines the accelerator opening using the second sensor 165b operating normally without using the first sensor 165a that is abnormal after time t4. Therefore, even if an abnormality occurs in one of the two sensors 165a and 165b, the vehicle control can be continued. This abnormal event # 4 is also an event in which the outputs of the two sensors 165a and 165b are both within the normal output ranges R1 and R2.

  The abnormal events # 3 and # 4 are all events classified as vibrations of the output signal, and these may be registered as the same event. Whether or not the event corresponds to the abnormal event # 3 or # 4 is determined by analyzing and examining characteristics peculiar to vibration such as the magnitude of the change rate of the output signal and its frequency (that is, the spectrum of the change rate). It is possible.

  FIG. 9 shows a change in the output signal when an abnormal event # 5 (difference abnormality) occurs in the two accelerator sensors 165a and 164b. When the accelerator sensor is operating normally, the difference between the two output signals AP1 and AP2 should be maintained within a substantially constant appropriate range. For example, if the slopes of the two input / output characteristics shown in FIG. 4A are the same, the difference between the two output signals AP1 and AP2 is substantially constant. Therefore, when the difference between the output signals of the two accelerator sensors deviates from a certain appropriate range, it can be determined that an abnormality has occurred in one of the sensors.

  When one output signal AP1 changes at time t0 in FIG. 9 and the two differences become a predetermined threshold value, the abnormality detection unit 272a supplies the abnormality preliminary notification PRE to the control input determination unit 272b. When the abnormality detection unit 272a confirms that the abnormality of the difference has continued for a predetermined period Δt5, the abnormality detection unit 272a determines that an abnormality has occurred in one of the sensors 165a and 165b (time t5). At this time, for example, a sensor (165a in the example of FIG. 9) whose output change is larger can be determined to be abnormal at time t0 when the difference is abnormal. At this time, the abnormality detection unit 272a supplies the abnormality detection command DET5 to the control input determination unit 272b to notify the first sensor 165a that the abnormal event # 5 has occurred.

  The master control CPU 272 determines the accelerator opening using the second sensor 165b operating normally without using the first sensor 165a that is abnormal after time t5. Therefore, even if an abnormality occurs in one of the two sensors 165a and 165b, the vehicle control can be continued. Also in this abnormal event # 5, it is possible to detect an abnormality of the sensor while the outputs of the two sensors 165a and 165b remain in the normal output ranges R1 and R2.

  In the case of a difference abnormality, the accelerator opening may be determined using a sensor output that gives a smaller accelerator opening in the provisional period Δt5. This method of determining the accelerator opening (control input) can also be applied to the other abnormal events described above.

  FIG. 10 is a flowchart showing a processing routine of the master control CPU 272 regarding detection of an abnormality of the accelerator sensor. This processing routine is started and executed at regular intervals. In step S1, the abnormality detection unit 272a checks whether or not an abnormal event has occurred at regular intervals. If no abnormal event has occurred in the accelerator sensor 165, this routine is terminated. On the other hand, when it is determined that an abnormal event has occurred in the accelerator sensor 165, subsequent control is continued using a normal sensor in step S2. In step S3, the fact that an abnormality has occurred in the sensor is registered in the EEPROM 282 (FIG. 3) in the abnormality history registration circuit 280.

  FIG. 11 is an explanatory diagram showing the contents of the abnormality history area in the EEPROM 282. In this abnormality history area, it is possible to register a flag indicating whether or not five abnormal events # 1 to # 5 have occurred for each trip. Here, one trip means one run of the vehicle (from key-on to key-off). In the EEPROM 282, a pointer PT for indicating the latest trip is also registered.

  FIG. 11A shows a state where the abnormality history area is initialized. FIG. 11B shows a state after the end of the three trips. In this example, the two sensors 165a and 165b were both normal in the first trip, but a difference abnormality occurred in the second trip, and a hold occurred in the third trip.

  Since the abnormality history is registered in the EEPROM 282 in this way, after the vehicle travels, by connecting the service computer to the control system 200 and reading out and examining the abnormality history from the EEPROM 282, what kind of abnormality occurred during the traveling. It is possible to know.

  As described above, in the four events # 2 to # 5 out of the five abnormal events # 1 to # 5 set in advance for the accelerator sensor, the outputs of the two sensors 165a and 165b are both normal output ranges. R1, R2. At this time, the abnormality detection unit 272a detects the abnormality of the sensor by checking whether or not the temporal change pattern of the output signal of the accelerator sensor corresponds to a plurality of preset abnormal event patterns. An abnormality can be detected even when the outputs of the two sensors are both within the normal range. Even if an abnormality occurs in one of the sensors, the control can be continued using a normal sensor. A plurality of preset abnormal event patterns are stored in a ROM (not shown) for the master control CPU 272.

E. Abnormal detection of shift position sensor:
FIG. 12 is an explanatory diagram showing the configuration of two types of shift position sensors 167a and 167b. The first shift position sensor 167a is an analog sensor (for example, a potentiometer) in which the output signal SP1 continuously changes as the shift lever moves. The second shift position sensor 167b is a switch type sensor constituted by a plurality of position switches SW1 to SW6 provided corresponding to a plurality of position positions.

  FIG. 13 is an explanatory diagram showing input / output characteristics of the two shift position sensors 167a and 167b. In the hybrid vehicle of this embodiment, five shift positions (that is, five ranges of P, R, N, D, and B) can be used. Here, the B range means a travel mode in which the engine brake is more effective than the D range.

  Regarding the analog sensor signal SP1, as shown on the vertical axis of the graph, a range of effective signal levels for each shift position is defined in advance. In the example of this figure, the value of the analog sensor signal SP1 (indicated by a black circle) is at a level within the effective range of the P range. As the position switch signal SP2, only the first switch SW1 indicating the P range is in an ON state (indicated by a black circle). Thus, when the two types of sensors 167a and 167b constituting the shift position sensor 167 are operating normally, the two types of sensors give the same control input (shift position).

  As for the shift position sensor 167, as in the case of the accelerator sensor 165 (FIG. 3), the master control CPU 272 executes functions as the abnormality detection unit 272a and the control input determination unit 272b.

  FIG. 14 is an explanatory diagram showing an abnormal event # 1 (switching sensor 167b ON abnormality) of the shift position sensor. In this example, the actual shift lever is in the D range and the analog sensor output SP1 correctly points to the D range, but the position switch signal SP2 is in the ON state of the two switches SW1 and SW4 indicating the P range and the D range. It has become. In this embodiment, in this way, even if an ON abnormality has occurred in the switch type sensor, if one position (D range) is pointed to by the two signals SP1 and SP2, the position is indicated. Is used as correct. Therefore, even if an abnormality occurs in one of the sensors, it is possible to continue control using a normal sensor.

  FIG. 15 shows an abnormal event # 2 (shift of analog sensor output) of the shift position sensor 167. In this example, the characteristic of the actual analog sensor output signal SP1 'is shifted upward from the characteristic of the correct signal SP1. In particular, the shift amount is large in the vicinity of the P range, and the shift amount decreases as it approaches the B range on the opposite side of the P range.

  In the example of FIG. 15A, the actual shift lever is in the P range and the position switch signal SP2 correctly indicates that it is in the P range, but the analog sensor signal SP1 is in an invalid range. In this case, since one position is not pointed to by the two signals SP1 and SP2, it is determined that the P range indicated by the position switch signal SP2 may also be wrong. The P range is not used for vehicle control.

  In the example of FIG. 15B, the actual shift lever is in the D range. The position switch signal SP2 indicates the D range, and the analog sensor signal SP1 also indicates the D range. As described above, even when the analog sensor signal SP1 ′ is shifted, when one position is pointed to by the two signals SP1 and SP2, the position is determined to be correct and used. To do. Therefore, even if an abnormality occurs in one of the sensors, the vehicle can be controlled using several positions.

  In the case of an abnormal shift of the analog sensor signal SP1 as shown in FIGS. 15A and 15B, the P range cannot be used, but there is a high possibility that other positions can be used. Therefore, even if such an abnormality occurs in the shift position sensor, the vehicle can be operated to the repair shop.

  When starting the vehicle, normally, the vehicle can be started only when the shift position is in the P range. This normal control is inconvenient because the vehicle cannot be started when an abnormality occurs in the P range as in the example of FIG. Therefore, when an abnormality has occurred in the P range and the N range is normal, it is preferable that the master control CPU 272 permit the vehicle to be started in the N range.

  When an abnormality has occurred in one of the two shift position sensors 167a and 167b, the operation of changing the shift position from the N range to the D range is enabled only when the driver is stepping on the brake. preferable. At this time, if the driver does not step on the brake, even if the driver changes the shift position sensor from the N range to the D range, the control input determination unit 272b invalidates the change and maintains the control in the N range. By so doing, it is possible to more reliably reflect the intention of the driver to change the shift position in vehicle control when an abnormality has occurred in the shift position sensor. In this sense, it is generally preferable that the operation of changing the shift position from the N range to the torque generation range (D range, B range, R range) is made effective only when the driver is stepping on the brake.

F. Variation:
The present invention is not limited to the above-described examples and embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

F1. Modification 1:
In each of the above embodiments, a so-called mechanical distribution type hybrid vehicle that uses a planetary gear to distribute engine power to the axle and the first motor MG1 has been described. However, the present invention does not use a planetary gear. The present invention is also applicable to a so-called electric distribution type hybrid vehicle that electrically distributes engine power using a generator. Since the electric distribution type hybrid vehicle is disclosed in, for example, Japanese Patent Application Laid-Open No. 9-46965 disclosed by the present applicant, the description thereof is omitted here.

  In addition, the present invention can be applied to other types of vehicles other than hybrid vehicles, and seed-type moving bodies such as airplanes and ships. That is, the present invention can be applied to a moving body using at least one prime mover. Furthermore, the present invention can also be applied to control other than the moving body.

F2. Modification 2:
In the above embodiment, two sensors are used to give the same control input. However, the present invention is generally applicable when a plurality of sensors are used to give the same control input. However, when only two sensors are provided, it is particularly difficult to determine which is abnormal when both outputs are within the normal range. Therefore, the present invention is particularly effective when only two sensors are used to provide the same control input. As the plurality of sensors, sensors having different input / output characteristics as in the above embodiment may be used, or sensors having the same input / output characteristics may be used.

F3. Modification 3:
Any memory other than the EEPROM 282 can be used as the memory in the abnormality history registration circuit 280 (FIG. 2). However, it is preferable to use a non-volatile memory such as an EEPROM in that the registered contents are not lost even if the power is lost.

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which shows the whole structure of the hybrid vehicle as 1st Example of this invention. 2 is a block diagram showing a more detailed configuration of the control system 200. FIG. The block diagram which shows the circuit structure relevant to the process of the output signal of an accelerator sensor. The graph which shows the characteristic of two sensors of the accelerator sensor 165. FIG. Explanatory drawing which shows abnormal event # 1 of an accelerator sensor. Explanatory drawing which shows abnormal event # 2 of an accelerator sensor. Explanatory drawing which shows abnormal event # 3 of an accelerator sensor. Explanatory drawing which shows abnormal event # 4 of an accelerator sensor. Explanatory drawing which shows abnormal event # 5 of an accelerator sensor. The flowchart which shows the process sequence of abnormality master control CPU272 regarding the abnormality detection of an accelerator sensor. Explanatory drawing which shows the content of the abnormality log | history area | region in EEPROM282. Explanatory drawing which shows the structure of two types of shift position sensors 167a and 167b. Explanatory drawing which shows the input-output characteristic of the shift position sensor 167 (FIG. 2). Explanatory drawing which shows abnormal event # 1 of a shift position sensor. Explanatory drawing which shows abnormal event # 2 of a shift position sensor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 112 ... Axle 114 ... Differential gear 116R, 116L ... Wheel 119 ... Case 120 ... Planetary gear 121 ... Sun gear 122 ... Ring gear 123 ... Planetary pinion gear 124 ... Planetary carrier 125 ... Sun gear shaft 126 ... Ring gear shaft 127 ... Planetary carrier shaft 129 ... Chain belt 130 ... Damper 131 ... Three-phase coil 132 ... Rotor 133 ... Stator 141 ... Three-phase coil 142 ... Rotor 143 ... Stator 144 ... Rotational speed sensor 149 ... Battery 150 ... Engine 156 ... Crankshaft 163 ... Brake sensor 165 ... Accelerator sensor 167 ... Shift Position sensors 191, 192 ... Drive circuit 194 ... Battery 196 ... Battery sensor 200 ... Control system 210 ... Main ECU
212 ... Bidirectional communication wiring 214 ... Bidirectional communication wiring 220 ... Brake ECU
230 ... Battery ECU
240 ... Engine ECU
260 ... motor control unit 262 ... motor main control CPU
262a ... Reset execution unit 264 ... First motor control CPU
266 ... Second motor control CPU
270: Master control unit 272: Master control CPU
272a ... Abnormality detection unit 272b ... Control input determination unit 274 ... Power supply control circuit 280 ... Abnormality history registration circuit 282 ... EEPROM

Claims (13)

A control device that controls a predetermined control object using first and second sensors for giving the same control input,
One of the first and second sensors is obtained by examining a change pattern of the output of the first and second sensors when the outputs of the first and second sensors are within normal output ranges, respectively. An anomaly detector that detects that an anomaly has occurred,
A control input determination unit that determines the control input using an output of a sensor other than the abnormality sensor when an abnormality sensor is detected by the abnormality detection unit;
A control device comprising: The control device according to claim 1,
The control device, wherein the abnormality detection unit detects the abnormality sensor by checking whether a change pattern of an output of each sensor corresponds to any of a plurality of preset abnormality patterns. The control device according to claim 2,
The plurality of abnormal patterns include a step change in sensor output, vibration of the sensor output, a change in the difference between the outputs of the first and second sensors, and a fixed state of the sensor output that cannot be taken when the sensor is normal. A control device comprising at least one of The control device according to claim 2, further comprising:
A control device having an abnormality history registration unit for registering an abnormality occurrence history indicating an abnormal pattern that has occurred. The control device according to any one of claims 1 to 4,
When the control input determining unit determines the control input using a sensor other than the abnormal sensor, the value of the control input is smaller than when both the first and second sensors are normal. The control apparatus which determines the said control input from the output of the said sensor according to such a determination method. The control device according to any one of claims 1 to 5,
When one of the outputs of the first and second sensors suddenly changes at a rate of change equal to or greater than a predetermined threshold, the control input determining unit is abnormal by the abnormality detection unit from the time when the output suddenly changes. A control device that determines the control input using an output of a sensor other than the sensor whose output has suddenly changed in a provisional period up to the time when it is determined whether or not there is. The control device according to any one of claims 1 to 5,
When one of the outputs of the first and second sensors suddenly changes at a rate of change equal to or greater than a predetermined threshold, the control input determining unit is abnormal by the abnormality detection unit from the time when the output suddenly changes. A control device that employs a smaller value of the two control inputs obtained from the outputs of the first and second sensors as the control input in a provisional period up to the time when it is determined whether or not there is. A control method for controlling a predetermined control object using first and second sensors for giving the same control input,
Detecting an abnormality in one of the first and second sensors by examining a change pattern of outputs of the first and second sensors;
A step of determining the control input using an output of a sensor other than the abnormality sensor when an abnormality sensor is detected by the abnormality detection unit;
A control method comprising: A moving object,
Prime mover,
A control device for controlling the operation of the prime mover;
With
The control device includes:
First and second sensors for providing identical control inputs;
An abnormality detection unit that detects that an abnormality has occurred in one of the first and second sensors by examining a change pattern of outputs of the first and second sensors;
A control input determination unit that determines the control input using an output of a sensor other than the abnormality sensor when an abnormality sensor is detected by the abnormality detection unit;
A moving object comprising: A control device that controls a predetermined control object using first and second sensors for giving the same control input,
If at least one of the outputs of the first and second sensors is abnormal and a control input that is substantially coincident with the output of the first and second sensors cannot be obtained, the first and second sensors When the control input obtained from the output is not used, and when the control input substantially coincides with the output of both the first and second sensors, the control input obtained from the first and second sensors is obtained. A control device that performs control using a control input. The control device according to claim 10,
The first sensor is an analog sensor that outputs an analog output signal indicating a shift position of a vehicle,
The second sensor is a switch type sensor composed of a plurality of switches that output a plurality of switch signals indicating a shift position of the vehicle.
Control device. A control method for controlling a predetermined control object using first and second sensors for giving the same control input,
If at least one of the outputs of the first and second sensors is abnormal and a control input that is substantially coincident with the output of the first and second sensors cannot be obtained, the first and second sensors A step of performing control without using the control input obtained from the output;
When at least one of the outputs of the first and second sensors is abnormal and the control input substantially coincides with the outputs of both the first and second sensors, the first and second sensors Controlling using the control input obtained from the output of
A control method comprising: A moving object,
Prime mover,
A control device for controlling the operation of the prime mover;
With
The control device includes:
If at least one of the outputs of the first and second sensors is abnormal and a control input that is substantially coincident with the output of the first and second sensors cannot be obtained, the first and second sensors When the control input obtained from the output is not used, and when the control input substantially coincides with the output of both the first and second sensors, the control input obtained from the first and second sensors is obtained. A moving object characterized by performing control using a control input.

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