Hybrid vehicle control device

Abstract

To appropriately determine whether a vehicle moves.SOLUTION: A hybrid vehicle control device is mounted on a hybrid vehicle together with an engine outputting power to a drive shaft connected to the hybrid vehicle shaft, a motor capable of inputting and outputting power to from and to the drive shaft and a gear mechanism connected to the drive shaft. When an instruction is made to start the engine while the hybrid vehicle is stopped, the hybrid vehicle control device executes pressing control controlling the motor so that pressing torque is output to press a gear of the gear mechanism toward one direction. When determining that the hybrid vehicle moves after starting the pressing control, the hybrid vehicle control device terminates the pressing control. The hybrid vehicle control device executes the pressing control after controlling the motor so that torque in an opposite direction to the pressing torque is output. The hybrid vehicle control device determines that the hybrid vehicle moves when a value obtained by subtracting a rotation amount of the motor to reduce a backlash of the gear from a rotation amount of the motor since start of the pressing control is larger than a predetermined amount.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a control device for a hybrid vehicle.

Background Art

[0002] Conventionally, as a control device for this type of hybrid vehicle, there has been proposed a device mounted on a hybrid vehicle, which includes an engine that outputs power to a drive shaft connected to an axle, a motor that can input and output power to the drive shaft, and a gear mechanism connected to the drive shaft (see, for example, Patent Document 1). In this device, when a start request for the engine is made during parking, a pressing control in which pressing torque is output from the motor is executed. Then, when the backlash of the gear mechanism is not eliminated during the pressing control, it is determined whether the vehicle is moving based on the rotation amount of the motor, and when the vehicle is moving, the pressing control is stopped.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-described control device for a hybrid vehicle, it is impossible to distinguish whether the rotation amount of the motor is due to the elimination of backlash or due to the movement of the vehicle. Therefore, it is desired to appropriately determine the movement of the vehicle from the rotation amount of the motor.

[0005] The control device for a hybrid vehicle of the present invention aims to appropriately determine whether the vehicle is moving.

Means for Solving the Problems

[0006] The control device for a hybrid vehicle of the present invention is An engine that outputs power to a drive shaft connected to an axle, a motor that can input and output power to and from the drive shaft, a gear mechanism connected to the drive shaft, all of which are mounted on a hybrid vehicle, and when a start instruction for the engine is given during a stop, pressing control is executed to control the motor so that a pressing torque for pressing the gears of the gear mechanism in one direction is output, and when it is determined that the hybrid vehicle is moving after starting the execution of the pressing control, a control device for a hybrid vehicle that aborts the pressing control After controlling the motor so that a torque in the direction opposite to the pressing torque is output, the pressing control is executed When a value obtained by subtracting the rotation amount of the motor for reducing the backlash of the gear from the rotation amount of the motor after starting the execution of the pressing control exceeds a predetermined value, it is determined that the hybrid vehicle is moving which is the gist.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0008] Next, embodiments for carrying out the present invention will be described using examples.

Examples

[0009] FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 equipped with a control device as an embodiment of the present invention. As shown in the figure, the hybrid vehicle 20 includes an engine 22, a planetary gear 30, motors MG1 and MG2, inverters 41 and 42, a battery 50, and an electronic control unit (hereinafter referred to as "HVECU") 70.

[0010] The engine 22 is configured as an internal combustion engine that outputs power using a hydrocarbon-based fuel such as gasoline or light oil. The engine 22 is under operation control by the ECU 70. 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, the drive shaft 36 connected to the drive wheels 39a and 39b via the differential gear 38 is connected to the ring gear, and the crankshaft 23 of the engine 22 is connected to the carrier. The motors MG1 and MG2 are configured as, for example, synchronous motor generators. The rotor of the motor MG2 is connected to the drive shaft 36. The inverters 41 and 42 are used to drive the motors MG1 and MG2 and are connected to the battery 50 via the power line 54. The motors MG1 and MG2 are rotationally driven by the ECU 70 by switching control of a plurality of switching elements (not shown) of the inverters 41 and 42. The battery 50 is configured as, for example, a lithium-ion secondary battery or a nickel-metal hydride secondary battery. This battery 50 is managed by the ECU 70. The ECU 70 includes, although not shown, a microcomputer having a CPU, a ROM, a RAM, a flash memory, an input / output port, and a communication port. Signals from various sensors are input to the ECU 70 via the input port. Examples of the signals input to the ECU 70 include signals from various sensors necessary for operation control of the engine 22, signals from various sensors necessary for drive control of the motors MG1 and MG2 such as the rotational positions θm1 and θm2 from a rotational position sensor (not shown) that detects the rotational positions of the rotors of the motors MG1 and MG2, and signals from various sensors necessary for management of the battery 50. From the ECU 70, various control signals for operation control of the engine 22, switching control signals to a plurality of switching elements (not shown) of the inverters 41 and 42, etc. are output via the output port.

[0011] In the hybrid vehicle 20 of the embodiment configured in this way, basically, under the control of the ECU 70, it travels in a hybrid driving (HV driving) mode accompanied by the operation of the engine 22 or an electric driving (EV driving) mode accompanied by the stoppage of the operation of the engine 22.

[0012] Next, the operation of the hybrid vehicle 20 of the embodiment configured in this way, particularly the operation when performing pressing control for pressing a gear (for example, a planetary gear 30, a differential gear 38, etc.) included in the drive train gear mechanism connected to the drive shaft 36 in one direction will be described. FIG. 2 is a flowchart showing an example of a control routine executed by the ECU 70. This routine is executed when a request for execution of pressing control (hereinafter referred to as a "pressing request") is made. This pressing request is made together with an instruction to start the engine 22 during a stop with the operation of the engine 22 stopped. When a predetermined time ts has elapsed since the instruction to start the engine 22 was given, that is, when a predetermined time ts has elapsed since the pressing request was made, the motor MG1 starts cranking the crankshaft 23 of the engine 22 to increase the rotational speed Ne of the engine 22, and when the rotational speed Ne of the engine 22 reaches a predetermined rotational speed Ns, fuel injection control, ignition control, etc. in the engine 22 are started to start the engine 22.

[0013] When this routine is executed, the ECU 70 sets the reverse torque Tm2ref1 to the target torque Tt of the motor MG2 (step S100), performs a slow change process of setting the torque command Tm2* to change toward the target torque Tt with a predetermined time constant so as to become the target torque Tt, and controls the inverter 42 so that the motor MG2 is driven by the torque command Tm2* (step S110). The reverse torque Tm2ref1 is a torque determined in advance by experiments, analysis, machine learning, etc. as a negative torque in the direction opposite to the positive pressing torque Tm2ref2 described later. Then, it is determined whether or not the time tref has elapsed (step S120), and steps S110 and S120 are repeated until the time tref has elapsed. The time tref is a time determined in advance by experiments, analysis, machine learning, etc. as the time for outputting the reverse torque Tm2ref1 from the motor MG2 to the drive shaft 36. By thus outputting the reverse torque Tm2ref1 from the motor MG2, the backlash of the gears of the drive train gear mechanism can be maximized.

[0014] When the time tref has elapsed in step S120, the rotational position θm2 of the motor MG2 is input from a rotational position sensor (not shown) that detects the rotational position of the rotor of the motor MG2 (step S130), and the input rotational position θm2 is set to the initial value θinit (step S140). Then, the positive pressing torque Tm2ref2 is set to the target torque Tt (step S150), a slow change process of setting the torque command Tm2* to change toward the target torque Tt with a determined time constant is performed, and pressing control is executed to control the inverter 42 so that the motor MG2 is driven by the torque command Tm2* (step S160). By thus outputting the pressing torque Tm2ref2 from the motor MG2 to the drive shaft 36, the backlash of the gears of the drive train gear mechanism can be reduced (rattling can be performed).

[0015] Subsequently, the rotational position θm2 is input by the same process as in step S130 (step S170), and a torsional rotation amount dθto, which is the rotational amount of the motor MG2 corresponding to the torsional angle of the drive shaft 36, is calculated by multiplying the torque command Tm2* by the conversion coefficient c (step S180). The conversion coefficient c is a value obtained by multiplying a conversion coefficient c1 for converting the torque output from the motor MG2 into the torsional angle of the drive shaft 36 by this torque by a conversion coefficient c2 for converting the torsional angle of the drive shaft 36 into the rotational amount θto (change amount of the rotational position θ) of the motor MG2. The conversion coefficients c1 and c2 are values determined in advance by experiments, analysis, machine learning, etc.

[0016] When the torsional rotation amount dθto is determined in this way, by subtracting the torsional rotation amount dθto and the reduction amount of the backlash of the gear of the drive train gear mechanism (the amount of clearance elimination), which corresponds to the rotation amount dθbr of the motor MG2, from the rotation amount dθ (= θm2 - θinit) of the motor MG2 obtained by subtracting the initial value θinit from the rotation position θm2 input in step S170, the rotation amount dθm2 of the motor MG2 corresponding to the moving distance of the vehicle is calculated (step S190), and it is determined whether the rotation amount dθm2 is greater than a threshold value (predetermined value) dθref that is a positive value (step S200). The threshold value dθref is a threshold value for determining whether the vehicle is moving. Here, the rotation amount dθm2 will be described. FIG. 3 is an explanatory diagram for explaining an example of the time change of the presence or absence of the pressing requirement, the torque command Tm2*, the rotation position θm2 of the motor MG2, and the torque command Tm1*. When the pressing requirement is made (at time t0), the torque command Tm2* gently changes toward the target torque Tt (= Tm2ref1, a negative value) set in step S100 and reaches the target torque Tt. Then, until the time tref elapses after the pressing requirement is made (at time t1), the torque command Tm2* is maintained at the target torque Tt. At this time, the gear of the drive train gear mechanism idles in the direction opposite to the pressing direction, that is, in the direction in which the backlash increases, as the motor MG2 rotates, that is, as the rotation position θm2 changes, and is held at the position where the backlash is maximum. When the time tref elapses after the pressing requirement is made, the torque command Tm2* gently changes toward the target torque Tt (= Tm2ref2) set in step S150 and reaches the target torque Tt. The gear of the drive train gear mechanism idles and the clearance is eliminated so that the backlash disappears as the drive shaft 36 is twisted as the motor MG2 rotates, and then the drive shaft 36 rotates after being twisted and the vehicle moves. Therefore, the rotation amounts dθbr and dθto of the motor MG2 do not contribute to the movement of the vehicle. In the embodiment, since the rotation amount dθm2 obtained by subtracting the rotation amount dθbr and the torsional rotation amount dθto from the rotation amount dθ in step S200 is used to determine whether the vehicle has moved, it is possible to appropriately determine whether the vehicle has moved.

[0017] When the rotation amount dθm2 is less than or equal to the threshold value dθref in step S200, it is determined that the vehicle is not moving, and it is determined whether or not the start of the engine 22 is completed (step S210). When the start of the engine 22 is not completed, the process returns to step S160, and the processes of steps S160 to S210 are repeated until the rotation amount dθm2 exceeds the threshold value dθref or the start of the engine 22 is completed. When the start of the engine 22 is completed in step S210, this routine ends. When the rotation amount dθm2 exceeds the threshold value dθref in step S200, it is determined that the vehicle is moving, the pressing control is stopped (step S220), and this routine ends. Thereby, the movement of the vehicle can be suppressed.

[0018] According to the hybrid vehicle 20 equipped with the control device of the embodiment described above, after controlling the motor MG2 so that the reverse torque Tm2ref1 is output, the pressing control is executed. When the rotation amount dθm2 obtained by subtracting the rotation amount dθbr and the torsional rotation amount dθto from the rotation amount dθ of the motor MG2 exceeds the threshold value dθref, it is determined that the vehicle is moving, so that it is possible to appropriately determine whether or not the vehicle has moved.

[0019] In the hybrid vehicle 20 equipped with the control device of the embodiment, in step S190, the value obtained by subtracting the rotation amount dθbr and the torsional rotation amount dθto from the rotation amount dθ is defined as the rotation amount dθm2. However, the value obtained by subtracting the rotation amount dθbr from the rotation amount dθ may be defined as the rotation amount dθ2.

[0020] As described above, the embodiments have been used to explain the embodiments for carrying out the present invention. However, the present invention is not limited to such embodiments, and it goes without saying that the present invention can be implemented in various forms without departing from the gist of the present invention.

Explanation of Reference Numerals

[0021] 20 Hybrid vehicle, 22 Engine, 30 Planetary gear, 70 Electronic control unit (ECU), MG1, MG2 Motors.

Claims

【Claim 1】 An engine that outputs power to a drive shaft connected to an axle, a motor that can input and output power to and from the drive shaft, a gear mechanism connected to the drive shaft, all of which are mounted on a hybrid vehicle. When a start instruction for the engine is given during a stop, pressing control is executed to control the motor so that a pressing torque for pressing the gear of the gear mechanism in one direction is output. When it is determined that the hybrid vehicle is moving after the start of the execution of the pressing control, a control device for the hybrid vehicle that aborts the pressing control, executes the pressing control after controlling the motor so that a torque in the direction opposite to the pressing torque is output, and determines that the hybrid vehicle is moving when a value obtained by subtracting the rotation amount of the motor for reducing the backlash of the gear from the rotation amount of the motor after the start of the execution of the pressing control exceeds a predetermined value. A control device for a hybrid vehicle.

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