JP2009248888A - Control device of hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device of a hybrid vehicle which can stop an engine at an early stage by promoting warm up of a battery. <P>SOLUTION: The control device of the hybrid vehicle is suitably utilized in order to control the hybrid vehicle which is provided with an engine, a motor generator which performs power generation by engine output, and a heater for warm up of battery for warming up the battery. The battery here is for example, the battery for driving. The control device of the hybrid vehicle has a control means. The control means makes the heater for warm up of the battery operated with power generated by the motor generator during stop or EV run of the hybrid vehicle. Thus warm up of the battery can be promoted. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control device for a hybrid vehicle that controls a hybrid vehicle.

  Conventionally, a technique for generating regenerative energy by regenerative operation of a motor (generator) during idling of an engine has been proposed. For example, Patent Document 1 describes a technique for operating a heater by increasing the engine speed and increasing the amount of power generated by a motor during idling. Such control is performed in order to properly operate the heater when the battery capacity is insufficient during idling.

JP-A-6-42343

  However, in the technique described in Patent Document 1 described above, no consideration is given to the case where the battery is warmed up when the vehicle interior is warmed up. Further, even when the warming up of the passenger compartment is completed, the engine cannot be stopped if the warming up of the battery is not completed.

  The present invention has been made to solve the above-described problems, and it is an object of the present invention to provide a control device for a hybrid vehicle that can promote warm-up of the battery and stop the engine early. And

  In one aspect of the present invention, a hybrid vehicle that controls a hybrid vehicle that includes an engine, a motor generator that generates electric power based on the output of the engine, and a battery warm-up heater for warming up the battery. The control device includes control means for operating the battery warm-up heater with the electric power generated by the motor generator when the hybrid vehicle stops or EV travels.

  In order to control a hybrid vehicle including an engine, a motor generator that generates electric power by the output of the engine, and a battery warm-up heater for warming up the battery. It is preferably used. Here, the battery is, for example, a driving battery. The control device for the hybrid vehicle has a control means such as an ECU (Electronic Control Unit). The control means activates the battery warm-up heater with the electric power generated by the motor generator when the hybrid vehicle is stopped or EV traveling. By doing in this way, warming up of a battery can be promoted.

  In another aspect of the hybrid vehicle control device, the hybrid vehicle includes a vehicle interior heater for heating the vehicle interior, and the control means includes a heating request level and a battery warm-up request level. Accordingly, the distribution ratio of the electric power generated by the motor generator to the battery warm-up heater and the vehicle interior heater is set. By doing so, both the battery warm-up heater and the vehicle interior heater can be operated efficiently, the engine can be stopped quickly, and fuel consumption can be improved.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

[Vehicle configuration]
First, a hybrid vehicle to which a hybrid vehicle control device according to this embodiment is applied will be described with reference to FIG.

  FIG. 1 is a diagram showing a schematic configuration of the hybrid vehicle 100. The hybrid vehicle 100 mainly includes an engine (internal combustion engine) 1, an axle 2, wheels 3, motors (motor generators) MG 1 and MG 2, a planetary gear 4, an inverter 5, a battery 6, and a vehicle interior heater. 7, a battery heater 8, and an ECU (Electronic Control Unit) 20.

  The axle 2 is a part of a power transmission system that transmits the power of the engine 1 and the motor MG2 to the wheels 3. The wheels 3 are wheels of the hybrid vehicle 100, and only the left and right front wheels are particularly shown in FIG. The engine 1 is constituted by a gasoline engine or the like, and functions as a power source that outputs the main driving force of the hybrid vehicle 100. The engine 1 is controlled variously by the ECU 20. Specifically, the ECU 20 controls the engine speed, and controls the opening (throttle opening) of a throttle valve (not shown).

  The motor MG1 is configured to function mainly as a generator for charging the battery 6 or a generator for supplying electric power to the motor MG2, and generates electric power by the output of the engine 1. The motor MG2 is mainly configured to function as an electric motor that assists (assists) the output of the engine 1. When the hybrid vehicle travels electrically (EV travel), it travels using the motor MG2 as a drive source without using the engine 1 as a drive source. These motors MG1 and MG2 are configured as, for example, synchronous motor generators, and include a rotor having a plurality of permanent magnets on the outer peripheral surface, and a stator wound with a three-phase coil that forms a rotating magnetic field. The planetary gear (planetary gear mechanism) 4 is configured to be able to distribute the output of the engine 1 to the motor MG1 and the axle 2 and functions as a power split mechanism.

  The inverter 5 is a DC / AC converter that controls power input / output between the battery 6 and the motors MG1 and MG2. For example, the inverter 5 converts the DC power taken out from the battery 6 into AC power, or supplies AC power generated by the motor MG1 to the motor MG2 and converts the AC power generated by the motor MG1 into DC power. It can be converted to and supplied to the battery 6.

  The battery 6 is a rechargeable storage battery configured to be able to function as a power source for driving the motor MG1 and the motor MG2. Hereinafter, the battery 6 may be simply referred to as a “battery”. The battery temperature sensor 6 b is a sensor that detects the temperature of the battery 6 (battery temperature), and transmits a detection signal corresponding to the detected battery temperature to the ECU 20. The battery heater 8 is, for example, a resistance heater or a Peltier heater, and is a device that generates heat by the supplied electric power and warms up the battery 6.

  The vehicle interior heater 7 is a device that generates heat by the supplied electric power and heats the vehicle interior. The vehicle interior temperature sensor 7b is a sensor that detects the temperature in the vehicle interior of the hybrid vehicle 100, and transmits a detection signal corresponding to the detected temperature in the vehicle interior to the ECU 20.

  The ECU 20 includes an unillustrated CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory), and is an electronic control unit that controls the overall operation of the hybrid vehicle 100. In the present embodiment, the ECU 20 operates the battery heater 8 with the electric power generated by the motor MG1 when the hybrid vehicle 100 stops or EV travels. Thereby, warming up of the battery 6 can be promoted.

  As can be seen from the above description, the ECU 20 functions as a control device for a hybrid vehicle in the present invention. Specifically, the ECU 20 operates as control means in the present invention.

  In the above, the embodiment has been described in which the ECU 20 executes both the control for the engine 1 and the control for the motors MG1, MG2, etc. However, the present invention is not limited to this. In another example, when there are separate ECUs for controlling the engine 1 and ECUs for controlling the motors MG1, MG2, etc., these ECUs cooperate to execute the control as described above. can do.

[Battery warm-up]
First, the warm-up method of the battery 6 will be specifically described. As described above, in the present embodiment, the ECU 20 operates the battery heater 8 with the electric power generated by the motor MG1 when the hybrid vehicle 100 stops or travels EV. Specifically, the ECU 20 determines whether or not there is a warm-up request for the battery 6 (hereinafter referred to as “battery warm-up request”) when the hybrid vehicle 100 stops or EV travels. When requested, the battery heater 8 is operated by the electric power generated by the motor MG1 without stopping the engine 1.

  The reason for this is that when the battery temperature is relatively low, the charge / discharge characteristics of the battery 6 deteriorate, and the battery can reach a temperature at which deterioration of the charge / discharge characteristics of the battery 6 can be prevented. This is because the temperature needs to be raised.

  Specifically, the ECU 20 determines whether or not the battery temperature is lower than the engine stop permission battery temperature based on the detection signal from the battery temperature sensor 6b when the hybrid vehicle 100 stops or EV travels. The engine stop permission battery temperature is a temperature at which deterioration of the charge / discharge characteristics of the battery 6 can be prevented, and is obtained in advance by experiments or the like and recorded in the ROM of the ECU 20 or the like.

  ECU20 determines with the battery warming-up request | requirement, when it determines with battery temperature being lower than engine stop permission battery temperature. At this time, even when the hybrid vehicle 100 is stopped or in the EV traveling state, the ECU 20 does not stop the engine 1 but generates electric power from the motor MG1 by the output of the engine 1, and uses electric power generated by the motor MG1. The battery heater 8 is activated. When the ECU 20 determines that the battery temperature has reached the engine stop permission battery temperature based on the detection signal from the battery temperature sensor 6b, the ECU 20 determines that the battery 6 has been warmed up, and the engine 1 Stop. As described above, warm-up of the battery 6 can be promoted.

[Control method]
Next, a control method when there is not only a battery warm-up request but also a vehicle interior heating request in a state where the hybrid vehicle 100 is stopped or EV traveling will be described. In this case, the ECU 20 causes the motor MG1 to generate electric power by the output of the engine 1 without stopping the engine 1 even when the hybrid vehicle 100 is stopped or running in EV, and uses the electric power generated by the motor MG1. The vehicle interior heater 7 and the battery heater 8 are operated.

  FIGS. 2A to 2E show the vehicle interior temperature, the power of the vehicle interior heater 7, the battery temperature, the battery heater 8 when the battery warm-up request level and the vehicle room heating request level are not considered. It is a graph which shows the change with respect to time about each of this electric power and an engine stop permission flag. In FIG. 2, the initial temperature of the passenger compartment temperature is Tsi, and the initial temperature of the battery temperature is Tdi.

  The electric power generated by the motor MG1 is supplied to both the vehicle interior heater 7 and the battery heater 8. Specifically, the electric power generated by the motor MG1 includes the vehicle interior heater 7 and the battery heater 8 until the vehicle interior temperature reaches the engine stop permission room temperature and the battery temperature reaches the engine stop permission battery temperature. And supplied to both. Here, the engine stop permission room temperature is a vehicle interior temperature that satisfies the heating requirement, and is set by a driver or the like, for example.

  When the degree of the battery warm-up request and the degree of the heating request in the vehicle interior are not taken into consideration, the distribution ratio of the electric power generated by the motor MG1 to the battery heater 8 and the vehicle interior heater 7 is a preset distribution. The ratio remains unchanged. In the example shown in FIG. 2, the electric power Ps1 supplied to the battery heater 8 is set to be larger than the electric power Pd1 supplied to the vehicle interior heater 7. At this time, as shown in FIG. 2, the battery temperature reaches the engine stop permitting battery temperature Tdm from the initial temperature Tdi as compared to the time ta1 until the vehicle interior temperature reaches the engine stop permitting room temperature Tsm from the initial temperature Tsi. The time ta2 until it becomes longer. Therefore, even when the vehicle interior temperature reaches the engine stop permission room temperature Tsm, the engine stop permission flag is not turned on until the battery temperature reaches the engine stop permission battery temperature Tdm. Takes time and fuel consumption deteriorates.

  Therefore, in the hybrid vehicle control device according to the present embodiment, the ECU 20 sends the battery heater 8 and the vehicle interior heater 7 to the battery heater 8 and the vehicle interior heater 7 according to the degree of the vehicle interior heating request and the battery warm-up request level. A distribution ratio of the electric power generated by the motor MG1 is set. Hereinafter, this will be specifically described with reference to FIG.

  3A to 3E show the vehicle interior temperature, the power of the vehicle interior heater 7, the battery temperature, and the battery heater 8 when the degree of battery warm-up request and the degree of vehicle interior heating request are taken into consideration. It is a graph which shows the change with respect to time about each of this electric power and an engine stop permission flag.

  The ECU 20 initially sets the power supplied to the vehicle interior heater 7 to Ps1 and the power supplied to the battery heater 8 to Pd1 (<Ps1), as in the case of FIG. However, the ECU 20 obtains, for example, the degree of request for heating in the vehicle interior and the degree of battery warm-up request at predetermined time intervals, and based on these, the distribution ratio of power to the battery heater 8 and the vehicle interior heater 7 is determined. Will be reset. In the example illustrated in FIG. 3, the ECU 20 determines the degree of the heating request and the degree of the battery warm-up request when the time tb1 has elapsed, and the battery for the battery according to the ratio between the degree of the heating request and the degree of the battery warm-up request. The distribution ratio of the electric power to the heater 8 and the vehicle interior heater 7 is reset.

  Specifically, the ECU 20 detects the vehicle interior temperature Ts1 based on the detection signal from the vehicle interior temperature sensor 7b when the time tb1 has elapsed, and based on the engine stop permission room temperature Tsm and the vehicle interior temperature Ts1. Find the degree of heating requirement. As a method for obtaining the degree of heating request, for example, the ECU 20 is a map indicating the degree of heating request with respect to the temperature difference between the engine stop permission room temperature and the detected vehicle interior temperature (hereinafter referred to as “heating request map”). In advance). The heating request map is set so that the degree of the heating request increases as the temperature difference between the engine stop permission room temperature and the detected vehicle interior temperature increases. ECU20 calculates | requires the degree of a heating request | requirement from a heating request | requirement map based on the detected vehicle interior temperature Ts1 and engine stop permission room temperature Tsm. That is, ECU20 calculates | requires the degree of the heating request | requirement corresponding to temperature difference Tsm-Ts1 from a heating request | requirement map.

  Similarly, when the time tb1 has elapsed, the ECU 20 detects the battery temperature Td1 based on the detection signal from the battery temperature sensor 6b, and warms up the battery based on the engine stop permission battery temperature Tdm and the battery temperature Td1. Find the degree of demand. As a method for obtaining the battery warm-up request level, for example, the ECU 20 is a map (hereinafter referred to as “battery warm-up request”) with respect to the temperature difference between the engine stop permission battery temperature and the detected battery temperature. (Referred to as “warm-up request map”). The battery warm-up request map is set so that the degree of battery warm-up request increases as the temperature difference between the engine stop permission battery temperature and the detected battery temperature increases. ECU20 calculates | requires the degree of battery warm-up request | requirement from a battery warm-up request | requirement map based on detected battery temperature Td1 and engine stop permission battery temperature Tdm. That is, the ECU 20 obtains the degree of battery warm-up request corresponding to the temperature difference Tdm−Td1 from the battery warm-up request map.

  As a result, in the example shown in FIG. 3, when the time tb1 has elapsed, it is determined that the degree of battery warm-up request is greater than the degree of heating warm-up request. The electric power to be supplied is set to Ps2 lower than Ps1, and the electric power supplied to the battery heater 8 is set to Pd2 (> Ps2) increased from Pd1. Thus, when the time tb2 elapses, the vehicle interior temperature reaches the engine stop permission room temperature Tsm, the battery temperature also reaches the engine stop permission battery temperature Tdm, and the engine stop permission flag is turned on. Here, the time tb2 is shorter than the time ta2 in FIG.

  That is, according to the control method of the hybrid vehicle according to the present embodiment, the motor to the battery heater 8 and the vehicle interior heater 7 according to the degree of the heating request in the vehicle interior and the degree of the battery warm-up request. By setting the distribution ratio of the electric power generated by MG1, both the vehicle interior heater 7 and the battery heater 8 can be operated efficiently, and the engine can be stopped quickly.

  Next, the hybrid vehicle control process will be described with reference to the flowchart shown in FIG. This control process is repeatedly executed by the ECU 20 at predetermined time intervals, for example.

  First, in step S101, the ECU 20 determines whether or not the hybrid vehicle 100 is stopped or EV traveling. If the ECU 20 determines that the hybrid vehicle 100 is stopped or EV traveling, the ECU 20 proceeds to the processing of step S102 (step S101: Yes), and the hybrid vehicle is not stopped and the EV traveling is not performed. When it determines (step S101: No), this control process is complete | finished.

  In step S102, the ECU 20 determines whether there is a heating request or a battery warm-up request. Specifically, the ECU 20 detects the vehicle interior temperature based on the detection signal from the vehicle interior temperature sensor 7b. When the detected vehicle interior temperature is lower than the engine stop permission room temperature Tsm, the ECU 20 determines that there is a heating request, and the detected vehicle interior temperature is equal to or higher than the engine stop permission room temperature Tsm. In the case, it is determined that there is no heating request. Further, the ECU 20 detects the battery temperature based on the detection signal from the battery temperature sensor 6b. When the detected battery temperature is lower than the engine stop permission battery temperature Tdm, the ECU 20 determines that there is a battery warm-up request, and the detected battery temperature becomes equal to or higher than the engine stop permission battery temperature Tdm. If it is, it is determined that there is no battery warm-up request. When it is determined that there is a heating request or a battery warm-up request, the ECU 20 proceeds to the process of step S103 (step S102: Yes), and when it is determined that neither of the heating request or the battery warm-up request exists. (Step S102: No), this control process is terminated.

  In step S103, the ECU 20 performs control to cause the motor MG1 to generate power. That is, the ECU 20 generates regenerative energy from the output of the engine 1 by the regenerative operation of the motor MG1. Thereafter, the ECU 20 proceeds to the process of step S104.

  In step S104, the ECU 20 determines the degree of the heating request. Specifically, the ECU 20 detects the vehicle interior temperature based on the detection signal from the vehicle interior temperature sensor 7b, and based on the detected vehicle interior temperature and the engine stop permission room temperature, from the heating request map. Find the degree of heating demand. The heating request map is obtained in advance by experiments or the like, and is recorded in the ROM of the ECU 20 or the like.

  In subsequent step S105, the ECU 20 determines the degree of battery warm-up request. Specifically, the ECU 20 detects the battery temperature based on the detection signal from the battery temperature sensor 6b, and from the battery warm-up request map based on the detected battery temperature and the engine stop permission battery temperature. The degree of battery warm-up request is obtained. The battery warm-up request map is obtained in advance by experiments or the like, and is recorded in the ROM of the ECU 20 or the like.

  In step S106, the ECU 20 sets a distribution ratio of the electric power generated by the motor MG1 to the battery heater 8 and the vehicle interior heater 7 based on the heating request level and the battery warm-up request level. . Specifically, the ECU 20 holds a table indicating the distribution ratio of the generated power of the motor MG1 with respect to the degree of heating request and the degree of battery warm-up request as shown in FIG. Based on the map, the distribution ratio of electric power to the battery heater 8 and the vehicle interior heater 7 is set. In the example shown in FIG. 5, the total power generated by the motor MG1 is 3 × 100W. In addition, the degree of the heating request and the degree of the battery warm-up request are values that do not exceed 3, and the sum of the values does not exceed 3.

  As shown in FIG. 5, when the heating request level is 0 and the battery warm-up request level is 1 or 2, the power supplied to the battery heater 8 is 3 × 100 W. That is, all the electric power generated by the motor MG1 is supplied to the battery heater 8 and used to warm up the battery 6. On the other hand, when the degree of heating request is 1 or 2, and the degree of battery warm-up request is 0, the electric power supplied to the vehicle interior heater 7 is 3 × 100 W. That is, all the electric power generated by the motor MG1 is supplied to the vehicle interior heater 7 and used for heating the vehicle interior. That is, when the degree of one of the heating request and the battery warm-up request is 0, all the electric power generated by the motor MG1 is supplied to the heater corresponding to the other request.

  When the heating request level is 1 and the battery warm-up request level is 2, the power supplied to the vehicle interior heater 7 is 1 × 100 W, and the power supplied to the battery heater 8 is 2 × 100 W. When the degree of heating request is 2 and the degree of battery warm-up request is 1, the power supplied to the vehicle interior heater 7 is 2 × 100 W, and the power supplied to the battery heater 8 is 1 × 100W. That is, when the values of the heating request level and the battery warm-up request level are different, the motor MG1 is supplied to the battery heater 8 and the vehicle interior heater 7 in accordance with the value of the request level. The electric power generated by is distributed.

  When the degree of heating request is 1 and the degree of battery warm-up request is 1, or when the degree of heating request is 2 and the degree of battery warm-up request is 2, The power supplied to the heater 7 is 1.5 × 100 W, and the power supplied to the battery heater 8 is 1.5 × 100 W. That is, when the values of the degree of demand of both are the same, the electric power generated by the motor MG1 is equally distributed to the battery heater 8 and the vehicle interior heater 7.

  Returning to the flowchart of FIG. 4, in step S106, the ECU 20 generates power by the motor MG1 to the battery heater 8 and the vehicle interior heater 7 based on the degree of the heating request and the degree of the battery warm-up request. After completing the setting of the power distribution ratio, the process proceeds to step S107. In step S107, the ECU 20 controls the battery heater 8 and the vehicle interior heater 7 so as to achieve the distribution ratio set in step S106, and then ends the present control process.

  As described above, both the vehicle interior heater 7 and the battery heater 8 can be operated efficiently. As a result, the engine can be stopped quickly, and fuel consumption can be improved.

1 shows a schematic configuration of a hybrid vehicle to which a hybrid vehicle control device according to the present embodiment is applied. It is a graph which shows the change with respect to the time about each temperature and the electric power of each heater in the case of not considering the degree of a battery warm-up request | requirement and the degree of the heating request | requirement of a vehicle interior. It is a graph which shows the change with respect to time about each temperature and the electric power of each heater at the time of considering the degree of a battery warm-up request | requirement, and the degree of the heating requirement of a vehicle interior. It is a flowchart which shows the control processing which concerns on this embodiment. It is a graph which shows the distribution ratio of the electric power generated of the motor with respect to the degree of a heating request, and the degree of a battery warm-up request.

Explanation of symbols

1 engine (internal combustion engine)
5 Inverter 6 Battery 6b Battery temperature sensor 7b Car interior temperature sensor 7 Car interior heater 8 Battery heater 20 ECU
MG1, MG2 motor

Claims (2)

A hybrid vehicle control device that controls a hybrid vehicle including an engine, a motor generator that generates electric power by the output of the engine, and a battery warm-up heater for warming up a battery,
A control device for a hybrid vehicle, comprising: control means for operating the battery warm-up heater with the electric power generated by the motor generator when the hybrid vehicle is stopped or EV traveled. The hybrid vehicle includes a vehicle interior heater for heating the vehicle interior,
The control means sets a distribution ratio of the electric power generated by the motor generator to the battery warm-up heater and the vehicle interior heater according to the degree of the heating request and the degree of the battery warm-up request. The hybrid vehicle control device according to claim 1.

Images