JP2007202222A - Controller of vehicle motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To ensure a running performance of a vehicle, and prevent a motor for driving the vehicle from being overheated in a running state of the vehicle with a high running resistance. <P>SOLUTION: A controller implements a method including steps S101-S103. If a difference between an estimated vehicle speed V0 based on a vehicle drive force and a detected vehicle speed V from a vehicle speed sensor is a threshold value ΔV1 or less in step S101, or an inverter temperature Ti is a predetermined value Ti1 or less and a motor temperature Tm is a predetermined value Tm1 or less in step S102, a torque characteristic map MAP1 is selected so as to obtain the maximum drive performance of the motor in step S103. If the difference between the estimated vehicle speed V0 and the detected vehicle speed V is larger than the threshold value ΔV1 in step S101, and the inverter temperature Ti is higher than the predetermined value Ti1 or the motor temperature Tm is higher than the predetermined value Tm1 in step S102, a torque characteristic map MAP2 is selected so as to obtain a torque limited lower than the torque characteristic map MAP1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a control device for a vehicle motor that controls a motor that drives the vehicle.

  In a vehicle such as a hybrid vehicle or an electric vehicle, it is possible to drive the vehicle by driving the motor. However, if the motor overheats, the motor cannot generate the torque necessary for driving the vehicle, thus preventing overheating of the motor. There is a need. Patent Documents 1 to 4 below disclose motor control devices that prevent overheating of motors and motor drive circuits (inverters).

JP-A-62-260594 JP-A-2005-86848 JP-A-6-90507 JP 11-355959 A

  For example, in a running state where the running resistance of the vehicle is high, such as sandy running or towing (towing) running, the vehicle speed is unlikely to increase despite the need to generate a large torque in the motor that drives the vehicle. Therefore, in such a traveling state, the temperature of the motor is likely to rise, and overheating is likely to occur. However, on the other hand, in order to ensure the running performance of the vehicle, the motor is also required to output a large torque. Thus, in the traveling state where the traveling resistance of the vehicle is high, it is required to satisfy both the traveling performance of the vehicle and the thermal performance of the motor.

  The present invention provides a control device for a motor for a vehicle that can ensure the driving performance of the vehicle and prevent overheating of the motor that drives the vehicle even in a driving state in which the driving resistance of the vehicle becomes high. With the goal.

  The vehicle motor control apparatus according to the present invention employs the following means in order to achieve the above-described object.

  The vehicle motor control device according to the present invention is a vehicle motor control device that controls a motor that drives the vehicle, and is in a high resistance state in which the running resistance of the vehicle is higher than a predetermined running resistance. A running resistance determination unit that determines whether or not, a temperature detection unit that detects at least one of the temperature of the motor and the temperature of the drive circuit that drives the motor, a determination result in the traveling resistance determination unit, and a temperature detection unit A torque characteristic setting unit that sets the torque characteristic of the motor based on the detected temperature, and a drive control unit that controls the torque of the motor within the range of the torque characteristic set by the torque characteristic setting unit. The gist.

  In one aspect of the present invention, the torque characteristic setting unit is configured to satisfy a condition including that the running resistance determination unit determines that the high resistance state is present and that the temperature detected by the temperature detection unit is higher than a predetermined value. It is preferable to set a torque characteristic in which the torque of the motor is limited as compared with the case where this condition is not satisfied.

  The vehicle motor control device according to the present invention is a vehicle motor control device that controls a motor that drives the vehicle, and is in a high resistance state in which the running resistance of the vehicle is higher than a predetermined running resistance. A motor based on a travel resistance determination unit that determines whether or not there is a torque acquisition unit that acquires the torque of the motor, a determination result in the travel resistance determination unit, and a motor torque history acquired in the torque acquisition unit And a drive control unit that controls the torque of the motor within the range of the torque characteristic set by the torque characteristic setting unit.

  In one aspect of the present invention, the torque characteristic setting unit determines that the high resistance state is determined by the running resistance determination unit, and the time when the motor torque acquired by the torque acquisition unit is equal to or greater than a set value is longer than a predetermined time. When a condition including continuing for a long time is satisfied, it is preferable to set a torque characteristic in which the torque of the motor is limited as compared with a case where this condition is not satisfied.

  A vehicle motor control apparatus according to the present invention is a vehicle motor control apparatus that controls a motor that drives a vehicle, and includes a vehicle position detection unit that detects the position of the vehicle, and a destination of the vehicle. At least one of a destination predicting unit to predict, a running resistance determining unit that determines a high resistance state in which the running resistance of the vehicle is higher than a predetermined running resistance, and the temperature of the motor and the temperature of the drive circuit that drives the motor A temperature detection unit that detects the above, and a vehicle position detected by the vehicle position detection unit and a vehicle destination predicted by the destination prediction unit when the running resistance determination unit determines the high resistance state; A torque characteristic setting unit that sets the torque characteristic of the motor based on the temperature detected by the temperature detection unit; a drive control unit that controls the torque of the motor within the range of the torque characteristic set by the torque characteristic setting unit; Having The gist.

  In one aspect of the present invention, a vehicle speed estimation unit that estimates the speed of a vehicle based on the driving force of the vehicle and a vehicle speed detection unit that detects the speed of the vehicle are provided. It is preferable to determine the high resistance state based on the estimated speed of the vehicle and the speed detected by the vehicle speed detection unit.

  In one aspect of the present invention, it is preferable that the vehicle includes a travel route acquisition unit that acquires a route along which the vehicle travels, and the travel resistance determination unit determines the high resistance state based on the route acquired by the travel route acquisition unit. It is.

  According to the present invention, it is possible to set the torque characteristics of the motor so as to satisfy both the running performance of the vehicle and the thermal performance of the motor even in a running state in which the running resistance of the vehicle becomes high. This can be ensured and overheating of the motor driving the vehicle can be prevented.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings.

  FIG. 1 is a diagram showing a schematic configuration of a drive system for a hybrid vehicle including a vehicle motor control device according to an embodiment of the present invention. An output shaft of an engine (internal combustion engine) 50 capable of generating power is connected to a power distribution mechanism 52. In addition to the output shaft of the engine 50, the power distribution mechanism 52 is also connected to the input shaft of the speed reducer 14 and the rotor of a generator (generator) 54 that can generate power. Here, the power distribution mechanism 52 can be constituted by, for example, a planetary gear mechanism having a ring gear, a carrier, and a sun gear. The output shaft of the speed reducer 14 is connected to the front wheel 19. The power distribution mechanism 52 distributes the power from the engine 50 to the front wheels 19 and the generator 54. The power distributed from the power distribution mechanism 52 to the front wheels 19 is used for driving the vehicle. On the other hand, the power distributed from the power distribution mechanism 52 to the generator 54 is converted into power generated by the generator 54. The electric power generated by the generator 54 can be supplied to the motors (electric motors) 10 and 56 capable of generating power via the inverter 12. Further, the electric power generated by the generator 54 can be recovered to the battery 16 via the inverter 12.

  The electric power from the battery 16 provided as a power storage device for storing electric energy is supplied to the windings (three-phase windings) of the motors 10 and 56 after power conversion (direct current to three-phase alternating current) is performed by the inverter 12. Is done. The motors 10 and 56 convert the electric power supplied to the windings from the inverter 12 into the power of the rotor. The rotor of the motor 10 is connected to the input shaft of the speed reducer 14 via the reduction mechanism 53, and the power of the motor 10 is transmitted to the front wheels 19 after being decelerated by the reduction mechanism 53 and the speed reducer 14. Used for driving. On the other hand, the rotor of the motor 56 is connected to the rear wheel 20, and the power of the motor 56 is transmitted to the rear wheel 20 to be used for driving the vehicle. Further, the regenerative operation of the motors 10 and 56 can convert the motive power of the vehicle into the electric power generated by the motors 10 and 56 and collect it in the battery 16 via the inverter 12. As described above, the hybrid vehicle according to the present embodiment can drive the front wheels 19 using the power generated by at least one of the engine 50 and the motor 10 provided as a power source, and the motor. This is a four-wheel drive vehicle capable of driving the rear wheel 20 with 56 powers.

  The inverter 12 provided as a drive circuit drives the motors 10 and 56 by converting the DC power from the battery 16 into AC and supplying the AC to the motors 10 and 56 by the switching operation of the switching elements. The inverter 12, particularly the switching element, generates heat. In the present embodiment, in order to suppress overheating of the inverter 12, a cooler 18 that cools the inverter 12 (particularly the switching element) with a coolant (refrigerant) is provided.

  In this embodiment, as a sensor for detecting the traveling state of the hybrid vehicle, an inverter temperature sensor 61 for detecting the temperature of the coolant in the cooler 18, that is, the temperature Ti of the inverter 12, and a motor for detecting the temperature Tm of the motor 56 are used. A temperature sensor 62, a vehicle speed sensor 63 that detects a vehicle speed (vehicle speed) V, and an accelerator opening sensor 64 that detects an accelerator opening A are provided.

  The electronic control unit 42 is configured as a microprocessor centered on a CPU, and includes a ROM that stores a processing program, a RAM that temporarily stores data, and an input / output port. The electronic control unit 42 includes a signal indicating the temperature (coolant temperature) Ti of the inverter 12 from the inverter temperature sensor 61, a signal indicating the temperature Tm of the motor 56 from the motor temperature sensor 62, and a vehicle speed from the vehicle speed sensor 63. A signal indicating V, a signal indicating the accelerator opening A from the accelerator opening sensor 64, and the like are input via the input port. On the other hand, the electronic control unit 42 outputs a drive control signal and the like for performing drive control of the engine 50, the motors 10 and 56, and the generator 54 via an output port. Note that drive control of the motors 10 and 56 and the generator 54 can be performed by switching control of the switching elements of the inverter 12.

  For example, in a traveling state in which the traveling resistance of the vehicle is high, such as sandy traveling or towing (traction) traveling, the motor 10 or 56 is unlikely to increase in spite of the necessity of generating a large torque in the motor 10 or 56. And the temperature of the inverter 12 is likely to rise. In particular, since the motor 56 that drives the rear wheel 20 is mounted on the rear side of the vehicle, it is less likely to be cooled than the motor 10 that is mounted on the front side of the vehicle and drives the front wheel 19 and is likely to overheat. On the other hand, in order to ensure the running performance of the vehicle, the motor 56 is also required to output a large torque within a range where the motor 56 is not overheated. In the present embodiment, the electronic control unit 42 controls the torque of the motor 56 so as to satisfy both the running performance of the vehicle and the thermal performance of the motor 56. Hereinafter, a configuration example for the electronic control unit 42 to control the torque of the motor 56 will be described. As shown in FIG. 2, the electronic control unit 42 includes a vehicle speed estimation unit 70, a running resistance determination unit 71, a torque characteristic storage unit 72, a torque characteristic setting unit 73, and a drive control unit 74 described below.

  The vehicle speed estimation unit 70 estimates the vehicle acceleration α0 based on the driving force of the vehicle, and estimates the vehicle speed V0 by integrating (accumulating) the estimated acceleration α0. Here, the acceleration α0 of the vehicle is estimated with respect to a preset running resistance of the vehicle. Further, the driving force of the vehicle here can be calculated based on the torque of the engine 50 and the torques of the motors 10 and 56. The torque of the engine 50 can be estimated based on, for example, a throttle opening and an engine speed detected by a sensor (not shown). As for the torque of the motors 10 and 56, the target torque of the motors 10 and 56 set by the electronic control unit 42 can be used, or can be calculated from the currents of the motors 10 and 56 detected by a current sensor (not shown). it can.

  The traveling resistance determination unit 71 determines whether or not the traveling resistance of the vehicle is in a high resistance state in which the traveling resistance is higher than a predetermined traveling resistance. For example, in a traveling state in which the traveling resistance of the vehicle is high, such as sandy traveling or towing traveling, the vehicle speed V hardly increases even if the driving force of the vehicle is increased. Therefore, the vehicle speed V detected by the vehicle speed sensor 63 becomes the driving force of the vehicle. It becomes smaller than the estimated vehicle speed V0 based on it. Therefore, by determining whether or not the difference V0−V between the estimated vehicle speed V0 by the vehicle speed estimation unit 70 and the detected vehicle speed V by the vehicle speed sensor 63 is larger than the threshold value ΔV1 (ΔV1 ≧ 0), the running resistance of the vehicle is high. It can be determined whether or not it is in a resistance state. Here, it is determined whether or not the difference α0−α between the estimated acceleration α0 of the vehicle based on the driving force of the vehicle and the detected acceleration α of the vehicle by an acceleration sensor (not shown) is larger than the threshold value Δα1 (Δα1 ≧ 0). Also, it can be determined whether or not the running resistance of the vehicle is in a high resistance state.

  The torque characteristic storage unit 72 stores a plurality of torque characteristic maps of the motor 56. Here, as shown in FIG. 3, for example, as a torque characteristic map of the motor 56, a torque characteristic map MAP1 capable of maximizing the driving performance of the motor 56, and a torque (maximum torque) of the motor 56 than the torque characteristic map MAP1. Is stored in the torque characteristic map MAP2 in which is limited.

  The torque characteristic setting unit 73 is based on the determination result by the running resistance determination unit 71, the temperature Ti of the inverter 12 detected by the inverter temperature sensor 61, and the temperature Tm of the motor 56 detected by the motor temperature sensor 62. A torque characteristic map (MAP1 or MAP2) of the motor 56 read from the storage unit 72 is selected. Details of the process for setting the torque characteristic map of the motor 56 will be described later.

  The drive control unit 74 sets the target torque τ0 of the motor 56 within the range of the torque characteristic map of the motor 56 set (selected) by the torque characteristic setting unit 73 based on the accelerator opening A and the vehicle speed V, for example. The torque τ of the motor 56 is controlled by controlling the switching operation of the inverter 12 so that the torque τ of 56 matches the target torque τ0. In the torque characteristic maps MAP1 and MAP2 shown in FIG. 3, the maximum torque τmax of the motor 56 is set corresponding to the vehicle speed V. In the torque characteristic map (MAP1 or MAP2) selected by the torque characteristic setting unit 73, the drive control unit 74 determines that the target torque τ0 of the motor 56 is based on the accelerator opening A within a range equal to or less than the maximum torque corresponding to the vehicle speed V. Is set.

  Next, details of the process in which the electronic control unit 42 sets (selects) the torque characteristic map of the motor 56 will be described with reference to the flowchart of FIG. The process according to the flowchart of FIG. 4 is repeatedly executed at predetermined time intervals.

  First, in step S101, it is determined whether or not the vehicle is in a high resistance state in which the running resistance of the vehicle is higher than a predetermined running resistance. Here, the running resistance determination unit 71 determines whether or not the difference V0−V between the estimated vehicle speed V0 obtained by the vehicle speed estimation unit 70 and the vehicle speed V detected by the vehicle speed sensor 63 is greater than the threshold value ΔV1. When the difference V0−V between the estimated vehicle speed V0 and the detected vehicle speed V is equal to or less than the threshold value ΔV1 (when the determination result in step S101 is NO), it is determined that the running resistance of the vehicle is not in the high resistance state, and the process proceeds to step S103. . On the other hand, when the difference V0−V between the estimated vehicle speed V0 and the detected vehicle speed V is larger than the threshold value ΔV1 (when the determination result in step S101 is YES), it is determined that the running resistance of the vehicle is in a high resistance state. Proceed to S102. Here, when the difference α0−α between the estimated acceleration α0 of the vehicle based on the driving force of the vehicle and the detected acceleration α of the vehicle by the acceleration sensor is larger than the threshold value Δα1, the running resistance of the vehicle is in a high resistance state. It is also possible to determine that the running resistance of the vehicle is not in the high resistance state when the difference α0−α between the estimated acceleration α0 of the vehicle and the detected acceleration α is equal to or less than the threshold value Δα1.

  In step S102, at least a condition in which the temperature Ti of the inverter 12 detected by the inverter temperature sensor 61 is higher than the predetermined value Ti1, and a condition in which the temperature Tm of the motor 56 detected by the motor temperature sensor 62 is higher than the predetermined value Tm1. The torque characteristic setting unit 73 determines whether or not one of them is established. When the temperature Ti of the inverter 12 is equal to or lower than the predetermined value Ti1 and the temperature Tm of the motor 56 is equal to or lower than the predetermined value Tm1 (when the determination result of step S102 is NO), the process proceeds to step S103. On the other hand, when at least one of the condition where the temperature Ti of the inverter 12 is higher than the predetermined value Ti1 and the condition where the temperature Tm of the motor 56 is higher than the predetermined value Tm1 is satisfied (when the determination result of step S102 is YES), The process proceeds to S104. In addition, about the predetermined value Ti1, Tm1, the value of the grade which the inverter 12 and the motor 56 do not overheat is preset.

  In step S 103, the torque characteristic map MAP 1 is read from the torque characteristic storage unit 72, so that the torque characteristic map MAP 1 is selected by the torque characteristic setting unit 73. In the selected torque characteristic map MAP1, the torque τ of the motor 56 is controlled based on the accelerator opening A within a range equal to or less than the maximum torque τmax1 corresponding to the vehicle speed V.

  On the other hand, in step S104, the torque characteristic map MAP2 is read out from the torque characteristic storage unit 72, so that the torque characteristic map MAP2 is selected by the torque characteristic setting unit 73. In the selected torque characteristic map MAP2, the torque τ of the motor 56 is controlled based on the accelerator opening A within a range equal to or less than the maximum torque τmax2 corresponding to the vehicle speed V. Note that the maximum torque τmax2 of the torque characteristic map MAP2 is set in advance to a value that allows the rate of temperature increase of the motor 56 and the inverter 12 to be kept low and allows sandy traveling, towing traveling, and the like.

  In the above processing, when it is determined that the running resistance of the vehicle is not in the high resistance state, it is determined that the temperature rise of the motor 56 and the inverter 12 is small and the possibility that the motor 56 and the inverter 12 are overheated is low. . In this case, the torque characteristic setting unit 73 can ensure the vehicle's running performance to the maximum by selecting the torque characteristic map MAP1 that can maximize the driving performance of the motor 56. Even when it is determined that the running resistance of the vehicle is in a high resistance state, when the temperature Ti of the inverter 12 is equal to or lower than the predetermined value Ti1 and the temperature Tm of the motor 56 is equal to or lower than the predetermined value Tm1, the motor 56 or the inverter It is judged that there is little possibility of causing 12 overheating. Also in that case, the torque characteristic setting unit 73 can ensure the vehicle running performance to the maximum by selecting the torque characteristic map MAP1.

  On the other hand, it is determined that the running resistance of the vehicle is in a high resistance state, and at least one of the condition that the temperature Ti of the inverter 12 is higher than the predetermined value Ti1 and the condition that the temperature Tm of the motor 56 is higher than the predetermined value Tm1 is satisfied. In this case, it is determined that there is a possibility that the motor 56 or the inverter 12 is overheated and the motor 56 or the inverter 12 is overheated. In that case, the torque characteristic setting unit 73 selects a torque characteristic map MAP2 in which the torque of the motor 56 is limited rather than the torque characteristic map MAP1, so that it is possible to perform sandy road traveling, towing traveling, and the like. While traveling performance can be ensured, the temperature rise of the motor 56 and the inverter 12 can be suppressed. In the hybrid vehicle, when the vehicle power is lower than the required vehicle power by limiting (decreasing) the torque of the motor 56, the decrease in the vehicle power can be compensated by the power of the engine 50.

  Therefore, according to the present embodiment, for example, even in a high resistance state in which the traveling resistance of the vehicle is high, such as sandy traveling or towing traveling, the traveling performance of the vehicle can be ensured, and the motor 56 and the inverter 12 can be overheated. Can be prevented. Further, in the present embodiment, by comparing the estimated vehicle speed V0 based on the driving force of the vehicle and the vehicle speed V detected by the vehicle speed sensor 63, it is possible to easily and accurately determine a high resistance state such as sandy land traveling or towing traveling. it can.

  Next, another configuration example of this embodiment will be described.

  In this embodiment, in step S102 of the flowchart of FIG. 4, the process proceeds to step S103 when the temperature Ti of the inverter 12 is equal to or lower than the predetermined value Ti1, and proceeds to step S104 when the temperature Ti of the inverter 12 is higher than the predetermined value Ti1. It can also be configured as follows. In step S102, the process may proceed to step S103 when the temperature Tm of the motor 56 is equal to or lower than the predetermined value Tm1, and the process may proceed to step S104 when the temperature Tm of the motor 56 is higher than the predetermined value Tm1. In the determination process in step S102, a condition in which the outside air temperature detected by an outside temperature sensor (not shown) is higher than a predetermined value can be used as the determination condition.

  In this embodiment, the torque characteristic setting unit 73 selects the torque characteristic map of the motor 56 to be read from the torque characteristic storage unit 72 based on the determination result by the running resistance determination unit 71 and the torque τ history of the motor 56. You can also In this embodiment, the torque characteristic setting unit 73 can also select a torque characteristic map of the motor 56 from three or more types of torque characteristic maps. Hereinafter, details of the processing in that case will be described with reference to the flowchart of FIG. In the following description, for example, as shown in FIG. 6, a torque characteristic map MAP1 that can maximize the driving performance of the motor 56, and a torque characteristic in which the torque (maximum torque) of the motor 56 is more limited than the torque characteristic map MAP1. It is assumed that the map MAP2 and the torque characteristic map MAP3 in which the torque (maximum torque) of the motor 56 is more limited than the torque characteristic map MAP2 are stored in the torque characteristic storage unit 72.

  First, in step S201, as in step S101, it is determined whether or not the running resistance of the vehicle is in a high resistance state (whether or not the difference V0−V between the estimated vehicle speed V0 and the detected vehicle speed V is greater than the threshold value ΔV1). Is done. When the running resistance of the vehicle is not in the high resistance state (when the determination result of step S201 is NO), the process proceeds to step S204, and when the traveling resistance of the vehicle is in the high resistance state (when the determination result of step S201 is YES). Advances to step S202.

  In step S202, the time during which the torque τ of the motor 56 continues to be equal to or greater than the set value τ1 (hereinafter referred to as torque continuation time) t0 exceeds the predetermined time t1, and the temperature Tm of the motor 56 is higher than the predetermined value Tm1. The torque characteristic setting unit 73 determines whether or not both conditions are satisfied. When the torque continuation time t0 is equal to or shorter than the predetermined time t1, or when the temperature Tm of the motor 56 is the predetermined value Tm1 (when the determination result of step S202 is NO), the process proceeds to step S204. On the other hand, when the torque continuation time t0 exceeds the predetermined time t1 and the temperature Tm of the motor 56 is higher than the predetermined value Tm1 (when the determination result of step S202 is YES), the process proceeds to step S203. As for the torque τ of the motor 56, the target torque τ0 of the motor 56 set by the drive control unit 74 can be used, or can be calculated from the current of the motor 56 detected by a current sensor (not shown).

  In step S203, whether the condition that the torque continuation time t0 exceeds the predetermined time t2 (t2> t1) and the condition that the temperature Tm of the motor 56 is higher than the predetermined value Tm2 (Tm2> Tm1) is satisfied. It is determined by the characteristic setting unit 73. When the torque continuation time t0 is equal to or shorter than the predetermined time t2, or when the temperature Tm of the motor 56 is the predetermined value Tm2 (when the determination result of step S203 is NO), the process proceeds to step S205. On the other hand, when the torque continuation time t0 exceeds the predetermined time t2 and the temperature Tm of the motor 56 is higher than the predetermined value Tm2 (when the determination result of step S203 is YES), the process proceeds to step S206.

  In step S204, the torque characteristic map MAP1 is selected by the torque characteristic setting unit 73 as in step S103. In step S205, the torque characteristic map MAP2 is selected by the torque characteristic setting unit 73 as in step S104.

  In step S206, the torque characteristic map MAP3 is read from the torque characteristic storage unit 72, and the torque characteristic map MAP3 is selected by the torque characteristic setting unit 73. In the selected torque characteristic map MAP3, the torque τ of the motor 56 is controlled based on the accelerator opening A within a range equal to or less than the maximum torque τmax3 corresponding to the vehicle speed V. Note that the maximum torque τmax3 of the torque characteristic map MAP3 is set in advance to a value that can balance the heat generation amount of the motor 56 and the inverter 12 with the cooling performance, and can perform sandy land traveling, towing traveling, etc. at a minimum. Is done.

  In the above processing, when it is determined that the running resistance of the vehicle is not in the high resistance state, the torque characteristic setting unit 73 selects the torque characteristic map MAP1 that can maximize the driving performance of the motor 56, The driving performance of the vehicle can be ensured to the maximum. Even when it is determined that the running resistance of the vehicle is in the high resistance state, when the torque continuation time t0 of the motor 56 is not more than the predetermined time t1, or when the temperature Tm of the motor 56 is not more than the predetermined value Tm1 Therefore, it is determined that there is little possibility of overheating of the motor 56 and the inverter 12. Also in that case, the torque characteristic setting unit 73 can ensure the vehicle running performance to the maximum by selecting the torque characteristic map MAP1.

  On the other hand, it is determined that the running resistance of the vehicle is in a high resistance state, and both the condition that the torque continuation time t0 of the motor 56 exceeds the predetermined time t1 and the condition that the temperature Tm of the motor 56 is higher than the predetermined value Tm1 are satisfied. In this case, it is determined that there is a possibility that the motor 56 and the inverter 12 are overheated. In that case, the torque characteristic setting unit 73 selects a torque characteristic map MAP2 in which the torque of the motor 56 is limited rather than the torque characteristic map MAP1, so that it is possible to perform sandy road traveling, towing traveling, and the like. While traveling performance can be ensured, the temperature rise of the motor 56 and the inverter 12 can be suppressed.

  Furthermore, it is determined that the running resistance of the vehicle is in a high resistance state, and both the condition that the torque continuation time t0 of the motor 56 exceeds the predetermined time t2 and the condition that the temperature Tm of the motor 56 is higher than the predetermined value Tm2 are satisfied. In this case, it is determined that the possibility that the motor 56 and the inverter 12 are overheated is higher. In that case, the torque characteristic setting unit 73 selects the torque characteristic map MAP3 in which the torque of the motor 56 is limited rather than the torque characteristic map MAP2, so that sandy traveling, towing traveling, etc. can be performed at a minimum. The running performance of the vehicle can be ensured, and the temperature rise of the motor 56 and the inverter 12 can be further suppressed. In this way, by gradually limiting (decreasing) the torque of the motor 56, it is possible to prevent the driver of the vehicle from feeling uncomfortable due to a rapid decrease in the torque of the motor 56.

  In steps S202 and S203 in the flowchart of FIG. 5, instead of the condition that the temperature Tm of the motor 56 is higher than a predetermined value, the condition that the temperature Ti of the inverter 12 is higher than the predetermined value, the temperature Tm of the motor 56, and the inverter A condition in which at least one of the twelve temperatures Ti is higher than a predetermined value can also be used as the determination condition.

  Further, when the vehicle according to the present embodiment includes a vehicle position detection device that detects the current position of the vehicle and a navigation device that sets a route on which the vehicle travels, the travel resistance determination unit 71 is configured to provide a route on which the vehicle travels. It is also possible to determine whether or not the running resistance of the vehicle is in a high resistance state based on the above. The navigation device here stores road map data including road surface information such as sandy or paved roads in a map database, and when the operator inputs the destination of the vehicle, the current position of the vehicle A route along which the vehicle travels is set based on the (departure point) and the destination of the vehicle. The traveling resistance determination unit 71 can determine that the traveling resistance of the vehicle is in a high resistance state when the route on which the vehicle travels is a high resistance road surface such as sand.

  When the running resistance determining unit 71 determines that the running resistance of the vehicle is in a high resistance state, the torque characteristic setting unit 73 determines the current position of the vehicle, the destination of the vehicle, the temperature Tm of the motor 56, and the inverter 12. A torque characteristic map of the motor 56 is set based on the temperature Ti. For the destination of the vehicle here, the destination set by the navigation device can be used as the predicted destination. Using the travel distance (or travel time) to the destination, the maximum torque τmax of the motor 56, the current temperature Tm of the motor 56, and the current temperature Ti of the inverter 12, the motor 56 when the vehicle arrives at the destination. The temperature Tm of the inverter 12 and the temperature Ti of the inverter 12 can be calculated (predicted). Therefore, the torque characteristic setting unit 73 first calculates (predicts) the travel distance (or travel time) to the destination based on the current position of the vehicle and the destination (predicted destination) of the vehicle. Next, based on the calculated (predicted) travel distance (or travel time) to the destination, the current temperature Tm of the motor 56, and the current temperature Ti of the inverter 12, the time when the vehicle arrives at the destination A torque characteristic map of the motor 56 is calculated by calculating the maximum torque τmax of the motor 56 for keeping both the temperature Tm of the motor 56 and the temperature Ti of the inverter 12 below the allowable upper limit temperature. In the calculated torque characteristic map, the torque τ of the motor 56 is controlled within a range equal to or less than the maximum torque τmax.

  According to this configuration example, the vehicle arrives at the destination before the temperature Tm of the motor 56 and the temperature Ti of the inverter 12 reach the allowable upper limit temperature even in a high resistance state where the running resistance of the vehicle becomes high, such as running on sand. The maximum torque τmax of the motor 56 is set within a possible range. Therefore, the running performance of the vehicle can be ensured, and overheating of the motor 56 and the inverter 12 can be prevented.

  Further, when the traveling resistance determination unit 71 determines that the traveling resistance of the vehicle is in a high resistance state, the torque characteristic map of the motor 56 can be set according to the processing according to the flowchart of FIG. First, in step S301, the running resistance R of the vehicle is calculated by the running resistance determination unit 71. Here, the running resistance R of the vehicle can be estimated from the difference V0−V between the estimated vehicle speed V0 and the detected vehicle speed V or the difference α0−α between the estimated acceleration α0 and the detected acceleration α of the vehicle. Next, in step S302, the torque characteristic setting unit 73 estimates the temperature rise rate of the motor 56 (time change rate of the temperature Tm) dTm / dt from the running resistance R of the vehicle and the power of the motor 56. The power of the motor 56 here can be calculated from the current of the motor 56 and the vehicle speed V, for example. Next, in step S <b> 303, the torque characteristic setting unit 73 calculates the torque allowable time ts of the motor 56 from the temperature Tm of the motor 56 and the temperature increase rate dTm / dt thereof. The torque allowable time ts here is calculated as the time until the temperature Tm of the motor 56 reaches the allowable upper limit temperature.

  Next, in step S304, based on the allowable torque time ts and the vehicle speed V, the torque characteristic map of the motor 56 is selected from a plurality (preferably three or more types) of torque characteristic maps stored in the torque characteristic storage unit 72. It is selected by the characteristic setting unit 73. Here, the correspondence relationship between the combination of the allowable torque time ts and the vehicle speed V and the torque characteristic map is determined in advance, and the torque characteristic map corresponding to the combination of the allowable torque time ts and the vehicle speed V is selected. For example, when the vehicle speed V decreases, it is determined that the time until the vehicle arrives at the destination increases. Therefore, the torque of the motor 56 is limited with respect to the decrease of the vehicle speed V (the maximum torque of the motor 56 decreases). ) The relationship of the torque characteristic map with respect to the combination of the allowable torque time ts and the vehicle speed V is preset so that the torque characteristic map is selected. For example, when the allowable torque time ts decreases, it is determined that the temperature Tm of the motor 56 easily reaches the allowable upper limit temperature. Therefore, the torque characteristic map in which the torque of the motor 56 is limited with respect to the decrease of the allowable torque time ts. The relationship of the torque characteristic map with respect to the combination of the allowable torque time ts and the vehicle speed V is set in advance.

  According to this configuration example, since the maximum torque of the motor 56 can be gradually changed, it is possible to prevent the driver of the vehicle from feeling uncomfortable due to a sudden change in the torque of the motor 56.

  In the above description, the case where the present invention is applied to the control of the motor 56 that drives the rear wheel 20 has been described. However, the present invention can also be applied to control of the motor 10 that drives the front wheel 19.

  In the above description, the case where the present invention is applied to the hybrid vehicle having the configuration shown in FIG. 1 has been described. However, the present invention can also be applied to hybrid vehicles having other configurations. Furthermore, the present invention can be applied not only to hybrid vehicles but also to electric vehicles.

  As mentioned above, although the form for implementing this invention was demonstrated, this invention is not limited to such embodiment at all, and can be implemented with a various form in the range which does not deviate from the summary of this invention. Of course.

1 is a diagram showing a schematic configuration of a drive system for a hybrid vehicle including a vehicle motor control device according to an embodiment of the present invention. It is a block diagram which shows schematic structure of an electronic control unit. It is a figure which shows an example of the torque characteristic map of a motor. It is a flowchart explaining the process which an electronic control unit sets the torque characteristic map of a motor. It is a flowchart explaining the other process which an electronic control unit sets the torque characteristic map of a motor. It is a figure which shows an example of the torque characteristic map of a motor. It is a flowchart explaining the other process which an electronic control unit sets the torque characteristic map of a motor.

Explanation of symbols

  10, 56 Motor (electric motor), 12 Inverter, 14 Reducer, 16 Battery, 18 Cooler, 19 Front wheel, 20 Rear wheel, 42 Electronic control unit, 50 Engine (internal combustion engine), 52 Power distribution mechanism, 53 Reduction mechanism, 54 generator (generator), 61 inverter temperature sensor, 62 motor temperature sensor, 63 vehicle speed sensor, 64 accelerator opening sensor, 70 vehicle speed estimation unit, 71 travel resistance determination unit, 72 torque characteristic storage unit, 73 torque characteristic setting unit, 74 Drive control unit.

Claims (7)

A vehicle motor control device that controls a motor that drives a vehicle,
A running resistance determination unit that determines whether or not the running resistance of the vehicle is in a high resistance state in which the running resistance is higher than a predetermined running resistance;
A temperature detector that detects at least one of a temperature of the motor and a temperature of a drive circuit that drives the motor;
A torque characteristic setting unit that sets the torque characteristic of the motor based on the determination result in the running resistance determination unit and the temperature detected by the temperature detection unit;
A drive control unit for controlling the torque of the motor within the range of the torque characteristic set by the torque characteristic setting unit;
A vehicle motor control apparatus comprising: The vehicle motor control device according to claim 1,
The torque characteristic setting unit is not satisfied when a condition including that the running resistance determination unit determines that the high resistance state is present and that the temperature detected by the temperature detection unit is higher than a predetermined value is satisfied. A control apparatus for a motor for a vehicle, wherein a torque characteristic in which the torque of the motor is limited as compared with the case is set. A vehicle motor control device that controls a motor that drives a vehicle,
A running resistance determination unit that determines whether or not the running resistance of the vehicle is in a high resistance state in which the running resistance is higher than a predetermined running resistance;
A torque acquisition unit for acquiring the torque of the motor;
A torque characteristic setting unit that sets the torque characteristics of the motor based on the determination result in the running resistance determination unit and the torque history of the motor acquired in the torque acquisition unit;
A drive control unit for controlling the torque of the motor within the range of the torque characteristic set by the torque characteristic setting unit;
A vehicle motor control apparatus comprising: The vehicle motor control device according to claim 3,
The torque characteristic setting unit includes determining that the running resistance determination unit is in the high resistance state and continuing a time for which the torque of the motor acquired by the torque acquisition unit is equal to or greater than a predetermined value for a time longer than a predetermined time. When the condition is satisfied, a torque characteristic in which the motor torque is limited as compared with the case where the condition is not satisfied is set. A vehicle motor control device that controls a motor that drives a vehicle,
A vehicle position detector for detecting the position of the vehicle;
A destination prediction unit for predicting the destination of the vehicle;
A running resistance determination unit that determines a high resistance state in which the running resistance of the vehicle is higher than a predetermined running resistance;
A temperature detector that detects at least one of a temperature of the motor and a temperature of a drive circuit that drives the motor;
The vehicle resistance detected by the vehicle position detection unit, the vehicle destination predicted by the destination prediction unit, and the temperature detected by the temperature detection unit when the running resistance determination unit determines the high resistance state; A torque characteristic setting unit for setting the torque characteristic of the motor based on
A drive control unit for controlling the torque of the motor within the range of the torque characteristic set by the torque characteristic setting unit;
A vehicle motor control apparatus comprising: The vehicle motor control device according to any one of claims 1 to 5,
A vehicle speed estimation unit that estimates the speed of the vehicle based on the driving force of the vehicle;
A vehicle speed detector for detecting the speed of the vehicle;
With
The running resistance determination unit determines the high resistance state based on an estimated vehicle speed by the vehicle speed estimation unit and a detected vehicle speed by the vehicle speed detection unit. The vehicle motor control device according to any one of claims 1 to 5,
A travel route acquisition unit that acquires a route along which the vehicle travels;
The travel resistance determination unit determines the high resistance state based on the route acquired by the travel route acquisition unit.

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