Vehicle monitoring and control system

Abstract

The present invention provides a vehicle monitoring and control device that can suppress the misidentification of vehicle failures. [Solution] A vehicle monitoring and control device equipped with a sensor that receives a voltage from a power source and outputs an output signal based on the applied voltage, wherein it determines whether the output voltage of the power source is above a predetermined voltage (step S1), determines whether a predetermined condition exists under which the output voltage of the power source becomes unstable (step S2), and if the output voltage of the power source is above a predetermined voltage and the predetermined condition does not exist under which the output voltage of the power source becomes unstable, it determines a vehicle failure based on the output signal of the sensor (step S3).

Description

Technical Field

[0001] This invention relates to a vehicle monitoring and control device for determining vehicle failures.

Background Art

[0002] Patent Document 1 describes a belt-type continuously variable transmission control device that includes a primary pulley connected to an engine, a secondary pulley connected to a drive wheel, and a belt wound around the primary pulley and the secondary pulley, and continuously changes the transmission ratio between the engine and the drive wheel by changing the winding radius of the belt. This transmission control device is configured to vary the shift speed with an auto upshift that upshifts as the vehicle speed increases and a coast upshift that upshifts when the accelerator is released, and is configured to suppress being misjudged as an auto upshift during the coast upshift process. Specifically, a target primary rotational speed is obtained from the vehicle speed and the throttle opening, and a final target transmission ratio is obtained from the target primary rotational speed and the secondary rotational speed. Next, a transient target transmission ratio for realizing the final target transmission ratio is obtained, and a target transmission ratio deviation that is the deviation between the final target transmission ratio and the transient target transmission ratio is obtained. Then, when the time change rate of the target primary rotational speed is less than the coast upshift determination reference value that is negative, or when the target transmission ratio deviation is less than or equal to the auto upshift determination reference value, it is determined as a coast upshift.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The transmission control device described in Patent Document 1 determines the target primary rotational speed and final target gear ratio by detecting vehicle speed, throttle opening, etc. On the other hand, sensors that detect these parameters are usually configured to receive a voltage from a power supply and output a signal based on that voltage. Therefore, if the power supply voltage is low or unstable, the sensor's output signal will not increase or will fluctuate. In other words, there will be a discrepancy between the actual behavior and the sensor's detected value. In such cases, it may not be possible to properly determine the target primary rotational speed or final target gear ratio, set a gear ratio suitable for the driving conditions, or set a gear speed suitable for the driving conditions and driving operation.

[0005] Incidentally, there is a known vehicle equipped with a transmission control device that sets the gear ratio of the transmission mechanism based on the detection values ​​of various sensors installed in the vehicle, and a monitoring control device that independently of the transmission control device performs a failure judgment based on the detection values ​​of those sensors. This monitoring control device prevents the transmission control device from setting an incorrect gear ratio due to a failure of various electronic components installed in the vehicle. Specifically, for example, if the gear ratio set by the transmission control device increases rapidly due to a sudden change in the vehicle speed detected by a sensor, the monitoring control device determines whether the sudden increase in the gear ratio is due to an electronic component, and notifies the driver by illuminating a warning lamp or switches to fail-safe control. Therefore, as mentioned above, if the power supply voltage is low or unstable, the monitoring control device may misjudge a failure due to poor sensor detection accuracy.

[0006] This invention was made in view of the above-mentioned technical problems, and aims to provide a vehicle monitoring and control device that can suppress the misjudgment of vehicle failures. [Means for solving the problem]

[0007] To achieve the above objective, this invention provides a vehicle monitoring and control device comprising a sensor to which a voltage is applied from a power source and which outputs an output signal based on the applied voltage, and which determines a vehicle fail based on the output signal of the sensor, wherein the device comprises a controller for determining the fail, the controller comprising: a voltage determination unit for determining whether the output voltage of the power source is above a predetermined voltage; a condition determination unit for determining whether the output voltage of the power source is unstable under predetermined conditions; and a fail determination unit for determining a vehicle fail based on the output signal of the sensor when the voltage determination unit determines that the output voltage of the power source is above the predetermined voltage and the condition determination unit determines that the predetermined conditions are not met.

[0008] Furthermore, in this invention, the fail determination unit may determine that the vehicle has failed if at least one of the amount of change in the output signal of the sensor and the time rate of change of the output signal exceeds a predetermined threshold.

[0009] Furthermore, this invention further comprises an electronic device different from the sensor, which is powered by the power source, and the predetermined condition may include a condition that the power required for the electronic device is equal to or greater than a predetermined power.

[0010] Furthermore, this invention further includes a gear shifting mechanism that changes the gear ratio between the driving force source and the drive wheels of the vehicle, and the sensor may include a rotation speed sensor that detects the rotation speed of the rotating member on the output side of the gear shifting mechanism. [Effects of the Invention]

[0011] According to this invention, a vehicle failure is determined based on the sensor's output signal when the power supply's output voltage is above a predetermined voltage and the power supply's output voltage is not unstable under predetermined conditions. Therefore, it is possible to suppress the false determination that the vehicle has failed due to a decrease or fluctuation in the power supply's output voltage, which may result in the sensor not outputting an appropriate output signal or the sensor's output signal fluctuating. [Brief explanation of the drawing]

[0012] [Figure 1] This figure schematically shows an example of a vehicle equipped with a monitoring and control device according to an embodiment of this invention. [Figure 2] This is a block diagram illustrating the functional configuration of a monitoring and control device in an embodiment of the present invention. [Figure 3] This is a flowchart illustrating an example of control performed by the monitoring and control device in this embodiment of the invention. [Modes for carrying out the invention]

[0013] This invention will be described based on the embodiments shown in the figures. The embodiments described below are merely examples of how this invention can be implemented and do not limit it.

[0014] An example of a vehicle Ve in this embodiment of the present invention is schematically shown in Figure 1. The vehicle Ve shown in Figure 1 is equipped with an engine (ENG) 1 as a power source. This engine 1 is configured to generate power by burning a mixture of fuel, such as gasoline or diesel, and air, similar to conventional engines. Specifically, it is equipped with a throttle valve for controlling the amount of air drawn into the cylinder, a fuel injector for injecting fuel into the cylinder, and a spark plug for igniting the mixture of air and fuel. These throttle valves, combustion injectors, and spark plugs are configured to be operated by supplied electricity, and a power supply 2 is provided to supply power to these actuators.

[0015] Furthermore, a starter motor 3 is provided to crank the stopped engine 1. This starter motor 3 is also configured to operate when power is supplied from the power source 2 mentioned above.

[0016] Power supply 2 is configured to be rechargeable by being supplied with electricity generated by a generator such as an alternator 4, similar to the power supply installed in conventional vehicles.

[0017] A torque converter 6 is connected to the output shaft 5 of the engine 1. This torque converter 6 comprises a pump impeller 7 connected to the output shaft 5 of the engine 1 and a turbine runner 8 positioned opposite the pump impeller 7. A stator may also be provided to rectify the exhaust flow from the turbine runner 8. Furthermore, a lock-up clutch 10 is provided to set the difference in rotational speed between the pump impeller 7 and the turbine runner 8 to a desired difference in rotational speed, and to rotate the pump impeller 7 and the turbine runner 8 together.

[0018] An automatic transmission mechanism (TM) 12 is connected to the output shaft 11 of the torque converter 6. This automatic transmission mechanism 12 may be any of the various automatic transmission mechanisms provided in conventional vehicles. That is, it may be a stepped automatic transmission mechanism that changes the gear ratio in steps, or it may be a belt-type continuously variable transmission mechanism or a toroidal-type continuously variable transmission mechanism that continuously changes the gear ratio by changing the belt winding radius or changing the inclination angle of the power roller. Furthermore, it may be a hybrid continuously variable transmission mechanism that connects the engine, motor and output shaft via a differential mechanism, and can continuously change the engine speed by changing the rotational speed of the motor.

[0019] A pair of drive wheels 15 are connected to the output shaft 13 of the automatic transmission mechanism 12 via a differential gear unit 14.

[0020] The above automatic transmission mechanism 12 is configured to change the gear ratio according to the driving force, vehicle speed, etc. required by the vehicle Ve. Therefore, an accelerator opening sensor 17 that detects the operation amount of an accelerator device (for example, an accelerator pedal) not shown in the figure, and a wheel speed sensor 18 that detects the rotational speed of each drive wheel 15 are provided. When voltages are applied to these sensors 17 and 18 from the above power supply 2, they output signals (voltages or currents) based on the applied voltages. Therefore, the vehicle Ve shown in FIG. 1 is provided with a voltmeter 19 for detecting the output voltage of the power supply 2. This wheel speed sensor 18 corresponds to the "sensor" in the embodiment of this invention, and the drive wheel 15 corresponds to the "rotating member" in the embodiment of this invention.

[0021] In addition, the vehicle Ve is provided with various sensors such as a crank angle sensor that detects the rotational speed (rotation angle) of the engine 1, a turbine rotational speed sensor that detects the rotational speed of the turbine runner 8, a throttle opening sensor that detects the opening of the throttle valve, a shift position sensor that detects the operation position of the shift lever, and a sensor that detects the state of an ignition switch (start switch).

[0022] Based on the detection values of sensors such as the above accelerator opening sensor 17 and wheel speed sensor 18, a shift control device (hereinafter referred to as a shift controller) 20 for setting the gear ratio of the automatic transmission mechanism 12 is provided. This shift controller 20 is mainly composed of a microcomputer, similar to the controllers provided in conventional vehicles. Based on the input signals, arithmetic expressions and maps stored in advance, etc., it obtains the target gear ratio of the automatic transmission mechanism 12, and is configured to output a command signal to an actuator that performs shifting so as to achieve the obtained target gear ratio.

[0023] Specifically, for example, a shift map for setting a shift ratio using an accelerator operation amount and a vehicle speed as parameters is stored in the shift controller 20. The accelerator operation amount is detected by the accelerator opening sensor 17, and the vehicle speed is calculated based on the wheel speed detected by the wheel speed sensor 18, so as to determine the shift ratio of the automatic transmission mechanism 12. Or, the drive power required for the engine 1 is calculated from the required drive force based on the accelerator operation amount and the vehicle speed, and a target engine speed at which fuel efficiency is good is calculated when outputting the drive power. Then, the target shift ratio of the automatic transmission mechanism 12 is obtained based on the target engine speed and the vehicle speed. Note that the means for setting the shift ratio of the automatic transmission mechanism 12 may be the same as the means for setting the shift ratio of the automatic transmission mechanism provided in a conventional vehicle, and is not limited to the above means.

[0024] In addition, the vehicle Ve shown in FIG. 1 is provided with a monitoring control device (hereinafter referred to as a monitoring controller) 21 for determining a failure of the vehicle Ve. This monitoring controller 21 is mainly composed of a microcomputer, receives signals from predetermined sensors, determines a failure of the vehicle Ve based on the input signals, and outputs a signal based on the determination result to, for example, an actuator that lights (or blinks) a warning lamp not shown, or outputs it to another control device that executes fail-safe control.

[0025] FIG. 2 shows a block diagram for explaining the functional configuration of the monitoring controller 21. The monitoring controller 21 shown in FIG. 2 includes a voltage determination unit 22, a condition determination unit 23, and a failure determination unit 24.

[0026] The voltage determination unit 22 determines whether the output voltage of the power supply 2 is equal to or greater than a predetermined voltage. Specifically, the voltage determination unit 22 receives a signal from the voltmeter 19, which detects the output voltage of the power supply 2. The predetermined voltage is set to be, for example, equal to or greater than the voltage value that needs to be applied to the wheel speed sensor 18 in order to properly detect the rotational speed (wheel speed) of the drive wheels 15. In other words, the voltage determination unit 22 determines whether or not the sensor can output an appropriate detection value.

[0027] The condition determination unit 23 determines whether the output voltage of power supply 2 is unstable under predetermined conditions, such as when the amount of change in the output voltage of power supply 2 exceeds a predetermined amount, or when the rate of change of the output voltage of power supply 2 exceeds a predetermined rate of change. If a large amount of power is required by electronic devices other than the sensor, the output voltage of power supply 2 may fluctuate and fall below a predetermined voltage due to the power output from power supply 2. For example, when cranking engine 1, the output voltage of power supply 2 may fluctuate and fall below a predetermined voltage due to the power output from power supply 2 to drive the starter motor 3. The condition determination unit 23 stores conditions under which the output voltage of power supply 2 falls below a predetermined voltage due to power output from power supply 2 to electronic devices other than the sensor, and determines whether or not these conditions are met.

[0028] Furthermore, since the voltage of power supply 2 gradually decreases while engine 1 is stopped, the output voltage of power supply 2 may be below a predetermined voltage for a predetermined period of time after starting engine 1. In such cases, immediately after engine start, the voltage determination unit 22 may determine that the output voltage of power supply 2 is below a predetermined voltage, or the condition determination unit 23 may determine this by defining a predetermined period of time from engine start as a predetermined condition.

[0029] The fail detection unit 24 determines if the vehicle Ve has failed based on the output signals of sensors installed on the vehicle Ve. For example, it stores the previous value input from the wheel speed sensor 18 to the monitoring controller 21 and compares that previous value with the currently input value. If the amount or rate of change of the compared values ​​is greater than a predetermined amount or rate of change that cannot actually occur, it determines that an electronic component or other part installed on the vehicle Ve has failed.

[0030] Figure 3 shows a flowchart illustrating an example of control performed by the monitoring controller 21. In the control example shown in Figure 3, first, it is determined whether the output voltage of the power supply 2 is above a predetermined voltage (step S1). This step S1 is performed by the voltage determination unit 22.

[0031] If a negative determination is made in step S1 because the output voltage of power supply 2 is below a predetermined voltage, it may not be possible to output appropriate detection values ​​from sensors such as the wheel speed sensor 18. In such cases, if the failure of vehicle Ve is determined based on the sensor detection values, it may be incorrectly determined that vehicle Ve has failed even though it has not. Therefore, in this control example, the routine is terminated without determining whether vehicle Ve has failed based on the sensor detection values. If a negative determination is made in step S1, the failure of vehicle Ve may be determined based on parameters other than the sensor detection values, such as determining whether vehicle Ve has failed based on the output voltage or output current from the sensor.

[0032] Conversely, if step S1 is positively determined because the output voltage of power supply 2 is above a predetermined voltage, then it is determined whether or not there are predetermined conditions under which the output voltage of power supply 2 becomes unstable (step S2). This step S2 is performed by the condition determination unit 23. That is, it determines whether or not there are predetermined conditions, such as when the power required by other electronic devices other than the sensor is above a predetermined power, or when engine 1 is cranking. This determination can be made by reading whether or not another controller other than the monitoring controller 21 is outputting a signal to perform control corresponding to the above predetermined conditions.

[0033] If a positive determination is made in step S2 due to predetermined conditions causing the output voltage of power supply 2 to become unstable, for example, even if the wheel speed has not changed, the detected value of the wheel speed sensor 18 may drop sharply due to a sudden decrease in the output voltage of power supply 2 from above a predetermined voltage to below a predetermined voltage. In order to prevent determining a vehicle Ve failure in such a case, in this control example, if a positive determination is made in step S2, the routine is terminated without determining a vehicle Ve failure based on the sensor's detected value.

[0034] On the other hand, if step S2 is negatively determined because the predetermined conditions for the output voltage of power supply 2 to be unstable are not met, monitoring control is executed to determine if the vehicle Ve has failed based on the sensor's detected value (step S3), and this routine is terminated. Step S3 is executed by the fail determination unit 24. That is, for example, the previous value input to the monitoring controller 21 from a sensor provided on the vehicle Ve, such as the wheel speed sensor 18, is stored, and if the difference between the previous value and the value input this time is greater than or equal to a predetermined difference, that is, if the amount of change in the sensor's output signal or the time rate of change of the sensor's output signal is greater than or equal to a threshold, it is determined that an electronic component provided on the vehicle Ve has failed. If step S3 is executed and it is determined that the vehicle Ve has failed, a signal may be output to a notification device such as a warning light (not shown) to notify the driver or occupants that the vehicle has failed, or a signal indicating that the vehicle has failed may be output to another control device to execute fail-safe control.

[0035] As described above, when the output voltage of power supply 2 is above a predetermined voltage and the predetermined conditions for the output voltage of power supply 2 to be unstable are not met, monitoring control is performed to determine if vehicle Ve has failed based on the sensor's detected value. This prevents the monitoring controller 21 from mistakenly determining that vehicle Ve has failed due to a decrease or fluctuation in the output voltage of power supply 2, which may result in the sensor not outputting an appropriate detected value or the sensor's detected value fluctuating.

[0036] Furthermore, the vehicle in this embodiment of the invention is not limited to a vehicle equipped with an engine as a driving force source, but may also be an electric vehicle equipped with a motor as a driving force source, or a hybrid vehicle equipped with both an engine and a motor as driving force sources. In addition, the monitoring and control device in this embodiment of the invention is not limited to determining a vehicle failure based on a signal from a sensor that detects the rotational speed on the output side of the automatic transmission mechanism, but may also determine a vehicle failure based on a sensor that detects the rotational speed on the input side of the automatic transmission mechanism, or other sensors provided on the vehicle. [Explanation of Symbols]

[0037] 2 power supply 3. Starter motor 4 Alternator 12 Automatic transmission 15 drive wheels 17. Accelerator position sensor 18. Wheel speed sensor 19 Voltmeter 20 Gear shift controller 21. Monitoring Controller 22 Voltage determination unit 23 Condition judgment section 24 Fail detection unit Vehicle

Claims

1. A vehicle monitoring and control device comprising a sensor to which a voltage is applied from a power source and which outputs an output signal based on the applied voltage, wherein the vehicle fails based on the output signal of the sensor, The system includes a controller that determines the failure, The aforementioned controller, A voltage determination unit that determines whether the output voltage of the power supply is equal to or greater than a predetermined voltage, A condition determination unit that determines whether the output voltage of the power supply is unstable under predetermined conditions, The system includes a fail determination unit that determines if the output voltage of the power supply is equal to or greater than the predetermined voltage determined by the voltage determination unit, and if the predetermined condition is not met determined by the condition determination unit, it determines that the vehicle has failed based on the output signal of the sensor. A vehicle monitoring and control device characterized by the following features.

2. A vehicle monitoring and control device according to claim 1, The fail determination unit determines that the vehicle has failed if at least one of the amount of change in the output signal of the sensor or the time rate of change of the output signal exceeds a predetermined threshold. A vehicle monitoring and control device characterized by the following features.

3. A vehicle monitoring and control device according to claim 1, The system further comprises electronic equipment different from the sensor, which is powered by the aforementioned power source, The aforementioned predetermined conditions include the condition that the power required for the electronic device is equal to or greater than a predetermined power. A vehicle monitoring and control device characterized by the following features.

4. A vehicle monitoring and control device according to claim 1, The vehicle further comprises a transmission mechanism that changes the gear ratio between the power source and the drive wheels. The sensor includes a rotation speed sensor that detects the rotation speed of the rotating member on the output side of the transmission mechanism. A vehicle monitoring and control device characterized by the following features.

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