JP-7857116-B2 - Sensor diagnostic device

JP7857116B2JP 7857116 B2JP7857116 B2JP 7857116B2JP-7857116-B2

Inventors

篠崎友樹
高島卓也
黒沼邦彦

Assignees

株式会社SUBARU

Dates

Publication Date: 20260512
Application Date: 20220302

Claims (4)

A sensor diagnostic device used in a vehicle equipped with a first temperature sensor and a second temperature sensor, for detecting an abnormality in the first temperature sensor or the second temperature sensor, The system includes a processor and memory that are connected to each other in a manner that enables communication, and a control system that determines a sensor abnormality based on the temperature difference detected between the first temperature sensor and the second temperature sensor. The control system is After the aforementioned vehicle has come to a stop, Based on the first detected temperature detected by the first temperature sensor, the rate of decrease of the first detected temperature is calculated, and based on the second detected temperature detected by the second temperature sensor, the rate of decrease of the second detected temperature is calculated. Based on the changes between the first detected temperature and the second detected temperature, the reversal of the first detected temperature and the second detected temperature within a specified time after the vehicle stops is predicted. If it is predicted that the first detected temperature and the second detected temperature will not reverse, the determination of a sensor abnormality based on the detected temperature difference is initiated when the absolute value of the difference in the rate of decrease between the first detected temperature and the second detected temperature falls below a threshold. Sensor diagnostic device.
In the sensor diagnostic device according to claim 1, The control system is If it is predicted that the first detected temperature and the second detected temperature will reverse, the determination of a sensor abnormality based on the difference in detected temperatures will be initiated after a period of time longer than the specified time has elapsed since the vehicle stopped. Sensor diagnostic device.
A sensor diagnostic device used in a vehicle equipped with a first temperature sensor and a second temperature sensor, for detecting an abnormality in the first temperature sensor or the second temperature sensor, The system includes a processor and memory that are connected to each other in a manner that enables communication, and a control system that determines a sensor abnormality based on the temperature difference detected between the first temperature sensor and the second temperature sensor. The control system is After the aforementioned vehicle has come to a stop, Based on the first detected temperature detected by the first temperature sensor, the rate of decrease of the first detected temperature is calculated, and based on the second detected temperature detected by the second temperature sensor, the rate of decrease of the second detected temperature is calculated. Based on the changes between the first detected temperature and the second detected temperature, the reversal of the first detected temperature and the second detected temperature within a specified time after the vehicle stops is predicted. The control system is If it is predicted that the first detected temperature and the second detected temperature will not reverse, the determination of a sensor abnormality based on the detected temperature difference is initiated when the absolute value of the difference in the rate of decrease between the first detected temperature and the second detected temperature falls below a threshold , If it is predicted that the first detected temperature and the second detected temperature will reverse, the determination of a sensor abnormality based on the difference in detected temperatures will be initiated after a period of time longer than the specified time has elapsed since the vehicle stopped. Sensor diagnostic device.
In the sensor diagnostic device according to claim 2 or 3 , The control system is When determining a sensor malfunction based on the absolute value of the rate of decrease falling below the threshold, it is determined that a sensor malfunction has occurred if the absolute value of the detected temperature difference exceeds the first temperature difference threshold. When the determination of a sensor abnormality is initiated after the aforementioned waiting period has elapsed, a sensor abnormality is determined to have occurred if the absolute value of the detected temperature difference exceeds a second temperature difference threshold that is smaller than the first temperature difference threshold. Sensor diagnostic device.

Description

This invention relates to a sensor diagnostic device used in a vehicle equipped with a first temperature sensor and a second temperature sensor. Automobiles and other vehicles are equipped with multiple temperature sensors to detect the temperature of various parts and use it for various control purposes. For example, temperature sensors installed in vehicles include those that detect the engine coolant temperature, those that detect the transmission fluid temperature, and those that detect the battery cell temperature. However, in order to properly control a vehicle equipped with temperature sensors, it is necessary to ensure that the temperature sensors function correctly. Therefore, diagnostic devices have been developed that determine abnormalities in temperature sensors by performing so-called soak diagnostics on them (see Patent Documents 1-3). Japanese Patent Publication No. 2013-19484Japanese Patent Publication No. 2013-108404Japanese Patent Publication No. 2010-96023 This figure shows an example of an electric vehicle in which a sensor diagnostic device, which is one embodiment of the present invention, is used.This figure shows an example of a control system that constitutes a sensor diagnostic device.This figure shows an example of the basic structure of each control unit.This flowchart shows an example of the procedure for executing sensor diagnostic control by a control system.This flowchart shows an example of the procedure for executing sensor diagnostic control by a control system.This figure shows an example of the sensor temperature changes during sensor diagnostic control.This figure shows an example of the sensor temperature changes during sensor diagnostic control.This figure shows an example of the sensor temperature changes during sensor diagnostic control.This diagram shows the conditions for diagnostic cases 1-9.This figure shows the change in sensor temperature in diagnostic case 1.This figure shows the change in sensor temperature in diagnostic case 2.This figure shows the change in sensor temperature in diagnostic case 3.This figure shows the change in sensor temperature in diagnostic case 4.This figure shows the change in sensor temperature in diagnostic case 5.This figure shows the change in sensor temperature in diagnostic case 6.This figure shows the change in sensor temperature in diagnostic case 7.This figure shows the change in sensor temperature in diagnostic case 8.This figure shows the change in sensor temperature in diagnostic case 9. The embodiments of the present invention will be described in detail below with reference to the drawings. In the following description, identical or substantially identical components and elements will be denoted by the same reference numerals, and repeated descriptions will be omitted. [Vehicle configuration] Figure 1 shows an example of an electric vehicle (vehicle) 11 in which a sensor diagnostic device 10, which is one embodiment of the present invention, is used. Figure 2 shows an example of a control system 50 that constitutes the sensor diagnostic device 10. Note that the control system 50 shown in Figure 2 functions not only as the control system 50 for the sensor diagnostic device 10, but also as the control system 50 for the electric vehicle 11. As shown in Figures 1 and 2, the electric vehicle 11 is provided with an electric axle 14 that drives the wheels 13. The electric axle 14 has a motor generator 15 and a differential mechanism 16. The rotor 17 of the motor generator 15 is connected to the differential mechanism 16 via a gear train 18. The wheels 13 are connected to an axle 19 extending from the differential mechanism 16. An inverter 21 is connected to the stator 20 of the motor generator 15, and a battery pack 22 is connected to the inverter 21. The battery pack 22 is provided with two battery modules 30 and 40 connected in parallel, and each battery module 30 and 40 is provided with multiple battery cells 31 and 41 connected in series. The battery pack 22 also includes main relays 23 and 24 connected to the battery modules 30 and 40, and a battery control unit 25 that monitors the charging and discharging of the battery modules 30 and 40. Furthermore, the battery pack 22 is equipped with current sensors 32 and 42 for detecting the charging and discharging currents of the battery modules 30 and 40, voltage sensors 33 and 43 for detecting the voltages of the battery modules 30 and 40, and temperature sensors 34 and 44 for detecting the temperatures of the battery modules 30 and 40. In other words, the battery pack 22 is equipped with a first temperature sensor 34 for detecting the temperature of battery module 30 and a second temperature sensor 44 for detecting the temperature of battery module 40. Thus, the electric vehicle 11 is equipped with a first temperature sensor 34 for detecting the temperature of battery module 30 and a second temperature sensor 44 for detecting the temperature of battery module 40. [Control Sys