JP6862696B2 - Automobile - Google Patents

Description

The present invention relates to an automobile, and more particularly to an automobile provided with a traveling motor.

Conventionally, for this type of automobile, the output upper limit value of the motor is less than the required output for climbing when the motor outputs torque for reverse movement from the motor within the range of the output upper limit value of the motor and travels on an uphill road. Occasionally, warnings have been proposed (see, for example, Patent Document 1). In this automobile, such control can prompt the driver to operate the brake to prevent the vehicle from slipping down.

Japanese Unexamined Patent Publication No. 2007-185069

In the above-mentioned automobile, a warning is given after the upper limit of the output of the motor becomes less than the required output for climbing a slope. For this reason, there may be a case where the driver's braking operation is not in time and the vehicle cannot be sufficiently prevented (suppressed) from slipping down.

The main object of the automobile of the present invention is to more sufficiently suppress the occurrence of sliding down of the vehicle when traveling in reverse.

The automobile of the present invention has adopted the following means in order to achieve the above-mentioned main object.

The automobile of the present invention
An automobile including a traveling motor and a control device for controlling the motor.
The control device is
When the motor outputs torque for reverse movement within the allowable torque range of the motor to drive backward on an uphill road,
Estimate the future temperature, which is the temperature of the motor after a predetermined time,
Based on the future temperature, the future allowable torque, which is the allowable torque after the predetermined time, is estimated.
When the allowable torque in the future is less than the required reverse torque required for reverse driving, a warning is given.
The gist is that.

In the automobile of the present invention, when the motor outputs torque for reverse movement from the motor within the allowable torque range of the motor to drive backward on an uphill road, the future temperature, which is the temperature of the motor after a predetermined time, is estimated. Based on the estimated future temperature, the future allowable torque, which is the allowable torque after a predetermined time, is estimated, and when the future allowable torque is less than the reverse required torque required for reverse driving, a warning is issued. By issuing a warning, it is possible to urge the driver to perform an operation (brake operation) for suppressing the vehicle from sliding down when traveling backward on an uphill road. Then, by issuing a warning when the allowable torque in the future is less than the required torque for reverse movement, an operation for suppressing the vehicle from slipping down is performed as compared with a warning when the current allowable torque is less than the required reverse torque. It is possible to secure more sufficient time for the driver to perform (brake operation). As a result, it is possible to more sufficiently suppress the occurrence of the vehicle sliding down. Here, the "after a predetermined time" can be, for example, 4 seconds, 5 seconds, 6 seconds, or the like.

In such an automobile of the present invention, the control device may estimate the future temperature based on the rotation speed of the motor, the torque command, and the temperature. In this case, the control device estimates the temperature rise amount of the motor during the predetermined time from the present based on the rotation speed and torque command of the motor, and is based on the temperature rise amount and the temperature of the motor. The future temperature may be estimated. Further, the control device may estimate the loss of the motor based on the rotation speed and the torque command of the motor, and estimate the future temperature based on the loss and the temperature of the motor. In these cases, the future temperature can be estimated more appropriately.

Further, in the automobile of the present invention, the control device sets the allowable torque so as to be smaller when the temperature of the motor is high than when it is low, and is smaller than when the temperature is low in the future. The allowable torque in the future may be estimated so as to be. In this way, the permissible torque and the permissible torque in the future can be set more appropriately.

Further, in the automobile of the present invention, the control device sets the reverse reverse required torque so that when the climb on the reverse side of the road surface gradient is positive, the reverse torque is larger when the road surface gradient is large than when it is small. It may be a thing. In this way, the required reverse torque can be set more appropriately.

It is a block diagram which shows the outline of the structure of the hybrid vehicle 20 as one Example of this invention. It is explanatory drawing which shows an example of the map for setting an allowable torque. It is explanatory drawing which shows an example of the processing routine executed by the HVECU 70 of an Example. It is explanatory drawing which shows an example of the temperature rise amount estimation map about a certain rotation speed Nm2 of a motor MG2. It is explanatory drawing which shows an example of the map for setting the reverse torque required.

Next, a mode for carrying out the present invention will be described with reference to examples.

FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 as an embodiment of the present invention. As shown in the figure, the hybrid vehicle 20 of the embodiment includes an engine 22, a planetary gear 30, motors MG1 and MG2, inverters 41 and 42, a battery 50, and an electronic control unit for hybrid (hereinafter referred to as "HVECU"). 70 and.

The engine 22 is configured as an internal combustion engine that outputs power using gasoline, light oil, or the like as fuel. The engine 22 is operated and controlled by an electronic control unit for an engine (hereinafter, referred to as "engine ECU") 24.

Although not shown, the engine ECU 24 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. .. Signals from various sensors required to control the operation of the engine 22, for example, a crank angle θcr from the crank position sensor 23 that detects the rotational position of the crankshaft 26 of the engine 22 and the like are input to the engine ECU 24 from the input port. Has been done. Various control signals for controlling the operation of the engine 22 are output from the engine ECU 24 via the output port. The engine ECU 24 is connected to the HVECU 70 via a communication port. The engine ECU 24 calculates the rotation speed Ne of the engine 22 based on the crank angle θcr from the crank position sensor 23.

The planetary gear 30 is configured as a single pinion type planetary gear mechanism. The rotor of the motor MG1 is connected to the sun gear of the planetary gear 30. A drive shaft 36 connected to the drive wheels 39a and 39b via a differential gear 38 is connected to the ring gear of the planetary gear 30. The crankshaft 26 of the engine 22 is connected to the carrier of the planetary gear 30 via a damper 28.

The motor MG1 is configured as, for example, a synchronous motor generator, and as described above, the rotor is connected to the sun gear of the planetary gear 30. The motor MG2 is configured as, for example, a synchronous motor generator, and a rotor is connected to a drive shaft 36. The inverters 41 and 42 are connected to the motors MG1 and MG2 and also to the battery 50 via the power line 54. The motors MG1 and MG2 are rotationally driven by switching control of a plurality of switching elements (not shown) of the inverters 41 and 42 by an electronic control unit for a motor (hereinafter referred to as "motor ECU") 40.

Although not shown, the motor ECU 40 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. .. The motor ECU 40 has signals from various sensors required to drive and control the motors MG1 and MG2, for example, rotation positions θm1 from rotation position detection sensors 43 and 44 that detect the rotation positions of the rotors of the motors MG1 and MG2. , Θm2, the temperature tm2 of the motor MG2 from the temperature sensor 45 that detects the temperature of the motor MG2, and the like are input via the input port. From the motor ECU 40, switching control signals and the like to a plurality of switching elements (not shown) of the inverters 41 and 42 are output via the output port. The motor ECU 40 is connected to the HVECU 70 via a communication port. The motor ECU 40 calculates the rotation speeds Nm1 and Nm2 of the motors MG1 and MG2 based on the rotation positions θm1 and θm2 of the rotors of the motors MG1 and MG2 from the rotation position detection sensors 43 and 44.

The battery 50 is configured as, for example, a lithium ion secondary battery or a nickel hydrogen secondary battery, and is connected to the inverters 41 and 42 via a power line 54. The battery 50 is managed by an electronic control unit for batteries (hereinafter, referred to as "battery ECU") 52.

Although not shown, the battery ECU 52 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. .. Signals from various sensors necessary for managing the battery 50 are input to the battery ECU 52 via the input port. The signals input to the battery ECU 52 include, for example, the battery voltage Vb from the voltage sensor 51a installed between the terminals of the battery 50, the battery current Ib from the current sensor 51b attached to the output terminal of the battery 50, and the battery 50. The battery temperature Tb from the temperature sensor 51c attached to the above can be mentioned. The battery ECU 52 is connected to the HVECU 70 via a communication port. The battery ECU 52 calculates the storage ratio SOC based on the integrated value of the battery current Ib from the current sensor 51b. The storage ratio SOC is the ratio of the capacity of electric power that can be discharged from the battery 50 to the total capacity of the battery 50.

Although not shown, the HVECU 70 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. Signals from various sensors are input to the HVECU 70 via input ports. Examples of the signal input to the HVECU 70 include an ignition signal from the ignition switch 80 and a shift position SP from the shift position sensor 82 that detects the operating position of the shift lever 81. Here, the shift position SP includes a parking position (P position), a reverse position (R position), a neutral position (N position), a forward position (D position), and the like. Further, the accelerator opening Acc from the accelerator pedal position sensor 84 that detects the depression amount of the accelerator pedal 83, the brake pedal position BP from the brake pedal position sensor 86 that detects the depression amount of the brake pedal 85, and the vehicle speed sensor 88. The vehicle speed V can also be mentioned. Further, the road surface gradient θrd from the gradient sensor 89 that detects the slope of the road surface can also be mentioned. From the HVECU 70, a control signal to the warning light 90 and the like are output via the output port. As described above, the HVECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via a communication port.

The hybrid vehicle 20 of the embodiment configured in this way travels in the hybrid traveling (HV traveling) mode or the electric traveling (EV traveling) mode. Here, the HV driving mode is a mode in which the engine 22 is driven and the engine 22 is driven, and the EV driving mode is a mode in which the engine 22 is not driven.

Next, the operation of the hybrid vehicle 20 of the embodiment configured in this way, particularly the operation when the shift position SP is the R position will be described. Hereinafter, in the description when the shift position SP is the R position, the torque and the number of revolutions will be described with the reverse direction as positive, and the road surface gradient θrd will be described with the backward climbing side as positive.

When the shift position SP is the R position, the vehicle travels in the EV traveling mode. In the drive control when the shift position SP is in the R position, the HVECU 70 first determines the accelerator opening Acc from the accelerator pedal position sensor 84, the brake pedal position BP from the brake pedal position sensor 86, and the vehicle speed V from the vehicle speed sensor 88. The required torque Td * for reverse travel required for the drive shaft 36 is set based on the above. Subsequently, the allowable torque Tm2lim of the motor MG2 is set based on the temperature tm2 of the motor MG2 input from the temperature sensor 45 via the motor ECU 40. Here, in the embodiment, the allowable torque Tm2lim of the motor MG2 is given the temperature tm2 of the motor MG2 by predetermining the relationship between the temperature tm2 of the motor MG2 and the allowable torque Tm2lim and storing it as a map for setting the allowable torque. The corresponding allowable torque Tm2lim is derived from this map and set. An example of the allowable torque setting map is shown in FIG. As shown in the figure, the allowable torque Tm2lim of the motor MG2 sets the rated value Tm2rt of the motor MG2 when the temperature tm2 of the motor MG2 is equal to or lower than the predetermined temperature tm2a (for example, 150 ° C., 160 ° C., 170 ° C., etc.). When the temperature tm2 of MG2 is higher than the predetermined temperature tm2a, it is set to be smaller when the temperature tm2 is higher than when it is lower (specifically, it is set to be smaller as the temperature tm2 is higher). Then, a value 0 is set in the torque command Tm1 * of the motor MG1, the required torque Td * is limited by the allowable torque Tm2lim of the motor MG2, the torque command Tm2 * of the motor MG2 is set, and the torque command Tm1 of the motors MG1 and MG2 is set. *, Tm2 * are transmitted to the motor ECU 40. When the motor ECU 40 receives the torque commands Tm1 * and Tm2 *, the motor ECU 40 performs switching control of a plurality of switching elements of the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1 * and Tm2 *.

Next, a process executed in parallel with the above-mentioned drive control when the shift position SP is the R position and the road surface gradient θrd is positive (uphill on the reverse side) will be described. FIG. 3 is an explanatory diagram showing an example of a processing routine executed by the HVECU 70 of the embodiment. This routine is repeatedly executed in parallel with the above-mentioned drive control when the shift position SP is the R position and the road surface gradient θrd is positive.

When the processing routine of FIG. 3 is executed, the HVECU 70 first inputs data such as the rotation speed Nm2 of the motor MG2, the torque command Tm2 *, the temperature tm2, and the road surface gradient θrd (step S100). Here, the rotation number Nm2 of the motor MG2 is calculated based on the rotation position θm2 of the rotor of the motor MG2 from the rotation position detection sensor 44, and is input from the motor ECU 40 by communication. As the torque command Tm2 * of the motor MG2, the one set by the above-mentioned drive control is input. As the temperature tm2 of the motor MG2, the one detected by the temperature sensor 45 is input from the motor ECU 40 by communication. As the road surface gradient θrd, the one detected by the gradient sensor 89 is input.

When the data is input in this way, the temperature tm2 of the motor MG2 during the predetermined time T1 (for example, 4 seconds, 5 seconds, 6 seconds, etc.) from the present based on the input rotation speed Nm2 of the motor MG2 and the torque command Tm2 *. The temperature rise amount Δtm2 as the rise amount of is estimated (step S110). Here, in the embodiment, the temperature rise amount Δtm2 is illustrated as a plurality of temperature rise amount estimation maps in which the relationship between the torque command Tm2 * of the motor MG2 and the temperature rise amount Δtm2 is predetermined for each rotation speed Nm2 of the motor MG2. When the rotation speed Nm2 of the motor MG2 and the torque command Tm2 * are given, the torque command of the motor MG2 is displayed on the map corresponding to the rotation speed Nm2 of the motor MG2 among the multiple maps for estimating the amount of temperature rise. Tm2 * was applied to estimate the temperature rise amount Δtm2. FIG. 4 shows an example of a map for estimating the amount of temperature rise for a certain rotation speed Nm2 of the motor MG2. As shown in the figure, the temperature rise amount Δtm2 is increased when the torque command Tm2 * of the motor MG2 is large compared to when it is small. Specifically, the larger the torque command Tm2 * of the motor MG2, the larger the temperature increase amount Δtm2. It was supposed to be estimated. This is because the larger the torque command Tm2 * of the motor MG2, the larger the current supplied to the motor MG2 and the larger the amount of heat generated.

Subsequently, the estimated temperature rise amount Δtm2 of the motor MG2 is added to the temperature tm2 of the motor MG2 to estimate the future temperature tm2fu as the temperature of the motor MG2 after a predetermined time T1 (step S120). Then, based on the future temperature tm2fu of the motor MG2, the future allowable torque Tm2limfu as the allowable torque Tm2lim of the motor MG2 after T1 after a predetermined time is estimated (step S130). Here, in the embodiment, the future allowable torque Tm2limfu has the horizontal axis and the vertical axis of the map for setting the allowable torque of FIG. 2 from "temperature tm2" and "allowable torque Tm2lim" to "future temperature tm2fu" and "future allowable torque Tm2limfu". The future temperature tm2fu was applied to the one replaced with "" to estimate.

Then, the reverse reverse torque Tm2rq required for the reverse travel is set based on the road surface gradient θrd (step S140). Here, in the embodiment, the reverse required torque Tm2rq is stored in a ROM (not shown) as a map for setting the reverse required torque by predetermining the relationship between the road surface gradient θrd and the reverse required torque Tm2rq, and the road surface gradient θrd is given. And, the corresponding reverse torque required torque Tm2rq was derived from this map and set. FIG. 5 shows an example of a map for setting the required reverse torque. The reverse torque required torque Tm2rq is set so as to be larger when the road surface gradient θrd is larger than when it is smaller, and specifically, to be larger as the road surface gradient θrd is larger. This is because, when traveling backward on an uphill road, the larger the road surface gradient θrd, the greater the force acting on the vehicle in the forward direction (sliding direction).

Next, the future allowable torque Tm2limfu of the motor MG2 is compared with the reverse required torque Tm2rq (step S150). When the future allowable torque Tm2limfu of the motor MG2 is the reverse required torque Tm2rq or more, it is determined that the motor MG2 can output a torque of the reverse required torque Tm2rq or more after a predetermined time T1, that is, the driver depresses the accelerator pedal 83 greatly. If so, it is determined that the vehicle can travel backward without causing the vehicle to slide down, and the process returns to step S100.

When the future allowable torque Tm2lim is less than the reverse required torque Tm2rq in step S150, it is determined that the upper limit of the torque that can be output from the motor MG2 after the predetermined time T1 is less than the reverse required torque Tm2rq, that is, the driver presses the accelerator pedal 83. It is determined that the vehicle may slide down after the predetermined time T1 or slightly after the predetermined time T1 even if the vehicle is depressed significantly, and the warning light 90 is turned on to encourage the brake pedal 85 to be depressed (step S160). As a result, the operation (brake operation) for preventing the vehicle from slipping down is performed as compared with the case where the warning light 90 is turned on after the current allowable torque Tm2lim of the motor MG2 becomes less than the reverse torque required torque Tm2rq. It is possible to secure more time for the driver to do it. As a result, it is possible to more sufficiently suppress the occurrence of the vehicle sliding down.

Then, the vehicle is stopped and the temperature tm2 of the motor MG2 is further waited to be less than the threshold value tm2ref (steps S170 to S190). Here, for the threshold value tm2ref, for example, the above-mentioned predetermined temperature tm2a or a temperature in the vicinity thereof can be used, or a temperature slightly lower than the temperature at which the allowable torque Tm2lim becomes equal to the reverse required torque Tm2rq can be used. Then, when the vehicle stops and the temperature tm2 of the motor MG2 becomes less than the threshold value tm2ref, it is determined that the reverse traveling may be restarted, the warning light 90 is turned off (step S200), and this routine is terminated.

In the hybrid vehicle 20 of the embodiment described above, when the motor MG2 outputs a reverse torque within the range of the allowable torque Tm2lim of the motor MG2 and travels backward on an uphill road, the motor MG2 after a predetermined time T1 The future allowable torque tm2fu as the temperature is estimated, and the future allowable torque Tm2limfu as the allowable torque Tm2lim of the motor MG2 after a predetermined time T1 is estimated based on the estimated future temperature tm2fu of the motor MG2, and the estimated future allowable torque of the motor MG2 is estimated. When Tm2limfu is less than the reverse torque required torque Tm2rq, the warning light 90 is turned on. As a result, the operation (brake operation) for preventing the vehicle from slipping down is operated as compared with the one that lights the warning light 90 when the current allowable torque Tm2lim of the motor MG2 is less than the reverse torque required torque Tm2rq. It is possible to secure more time for the person to do it. As a result, it is possible to more sufficiently suppress the occurrence of the vehicle sliding down.

In the hybrid vehicle 20 of the embodiment, the temperature rise amount Δtm2 of the motor MG2 for a predetermined time T1 from the present is estimated based on the rotation speed Nm2 of the motor MG2 and the torque command Tm2 *, and the temperature rises to the current temperature tm2 of the motor MG2. The amount Δtm2 was added to estimate the future temperature tm2 of the motor MG2 after the predetermined time T1. However, the loss Lm2 of the motor MG2 is estimated based on the rotation speed Nm2 of the motor MG2 and the torque command Tm2 *, and the future temperature of the motor MG2 after a predetermined time T1 is estimated based on the loss Lm2 and the current temperature tm2 of the motor MG2. It may be used to estimate tm2.

In the hybrid vehicle 20 of the embodiment, the reverse torque required torque Tm2rq is set based on the road surface gradient θrd. However, when the road surface gradient θrd is a uniform value such as 14 °, 16 °, or 18 °, the vehicle moves backward. The torque required for traveling may be used.

In the hybrid vehicle 20 of the embodiment, the HVECU 70 executes the processing routine of FIG. 3 when the shift position SP is the R position and the road surface gradient θrd is positive. However, when the shift position SP is the R position, the processing routine of FIG. 3 may be executed regardless of the road surface gradient θrd. In this case, when the road surface gradient θrd is 0 or less, it is considered that the vehicle does not slide down. Therefore, the reverse torque required torque Tm2rq may be set to 0.

In the embodiment, the hybrid vehicle 20 including the engine 22, the planetary gear 30, and the motors MG1 and MG2 is configured. However, it may be configured as a so-called one-motor hybrid vehicle including an engine and one motor. Further, the electric vehicle may be configured to run by using only the power from the motor without the engine.

The correspondence between the main elements of the examples and the main elements of the invention described in the column of means for solving the problem will be described. In the embodiment, the motor MG2 corresponds to the "motor", the battery 50 corresponds to the "battery", and the HVECU 70 and the motor ECU 40 correspond to the "control device".

Regarding the correspondence between the main elements of the examples and the main elements of the invention described in the column of means for solving the problem, the invention described in the column of the means for solving the problem in the examples is carried out. Since it is an example for specifically explaining the form for solving the problem, the elements of the invention described in the column of means for solving the problem are not limited. That is, the interpretation of the invention described in the column of means for solving the problem should be performed based on the description in the column, and the examples are the inventions described in the column of means for solving the problem. It is just a concrete example.

Although the embodiments for carrying out the present invention have been described above with reference to examples, the present invention is not limited to these examples, and various embodiments are used without departing from the gist of the present invention. Of course, it can be done.

The present invention can be used in the automobile manufacturing industry and the like.

20 hybrid vehicle, 22 engine, 23 crank position sensor, 24 electronic control unit for engine (engine ECU), 26 crank shaft, 28 damper, 30 planetary gear, 36 drive shaft, 38 differential gear, 39a, 39b drive wheel, 40 motor Electronic control unit (motor ECU), 41,42 inverter, 43,44 rotation position sensor, 45 temperature sensor, 50 battery, 51a voltage sensor, 51b current sensor, 51c temperature sensor, 52 electronic control unit for battery (battery ECU), 54 power line, 70 electronic control unit for hybrid (HVECU), 80 ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal position sensor, 88 vehicle speed sensor , 89 gradient sensor, 90 warning light, MG1, MG2 motor.

Claims (1)

An automobile including a traveling motor and a control device for controlling the motor.
The control device is
When the motor outputs torque for reverse movement within the allowable torque range of the motor to drive backward on an uphill road,
Based on the rotation speed of the motor, the torque command, and the temperature, the future temperature, which is the temperature of the motor after a predetermined time, is estimated.
Based on the future temperature, the future allowable torque, which is the allowable torque after the predetermined time, is estimated.
When the allowable torque in the future is less than the required reverse torque required for reverse driving, a warning is given to prompt the brake pedal to be depressed.
Automobile.

Images