JP5115451B2 - Vehicle drive control device - Google Patents

Description

  The present invention relates to a drive control device for a vehicle, and more particularly, to a drive control device for a hybrid vehicle, an electric vehicle or the like provided with an electric motor for driving the vehicle.

  A hybrid vehicle or the like is equipped with an electric motor that drives the vehicle. An electric motor generates heat during driving due to copper loss, iron loss, etc., and when the output of the motor increases, the amount of generated heat also increases.For example, when the vehicle is running on a steep slope, the temperature of the motor increases. May rise significantly. If the motor is overheated, there may be a problem with the motor. Therefore, it is conceivable to limit the load factor of the motor torque from the viewpoint of component protection. Here, the load factor is a motor torque limiting rate, and the torque obtained by multiplying the maximum torque by the load factor is the output torque. The electric vehicle includes, for example, a drive control device that includes a load factor restriction map that defines a maximum load factor of the motor torque according to the motor temperature and restricts the motor torque based on the load factor restriction map. The load factor restriction map normally defines a predetermined temperature at which the load factor restriction is started and a load factor restriction value at a predetermined temperature or higher.

  When the temperature of the electric motor rises and reaches the predetermined temperature specified in the load factor restriction map, the load factor of the electric motor is restricted to protect the parts. There is. The predetermined temperature at which the load factor limitation of the electric motor is started is determined in consideration of a certain accumulated time, so even if the temperature of the electric motor exceeds the predetermined temperature, the parts are immediately It does not adversely affect durability. In particular, it is not preferable to limit the load factor uniformly when climbing up after a short while, for example, when climbing uphill. Therefore, depending on the running state of the vehicle, it is not preferable to limit the motor torque. It may be preferable to prioritize performance. On the other hand, if the motor torque is not limited at all with respect to the temperature rise of the motor, there is a possibility that the overheating state will continue and the motor will fail. Coexistence of such improvement in running performance and protection of the electric motor is strongly demanded particularly during uphill running.

  In view of such a situation, several control devices and the like have been proposed. For example, Patent Document 1 discloses a device that estimates the temperature of an electric motor based on navigation information and performs load factor restriction in advance, specifically, a vehicle based on road information including road altitude information. Based on the altitude information included in this travel route, the temperature of the electric motor when traveling along the travel route is predicted for each predetermined section, and the travel route of the electric motor is calculated. An apparatus is disclosed that performs output limitation of an electric motor or cooling of an electric motor when traveling in a section before a section where the temperature is predicted to exceed a predetermined temperature.

  Further, Patent Document 2 discloses a restriction for canceling or relaxing the driving force limit of the electric motor by the driving force limiting means when the vehicle reaches a predetermined driving state (for example, a driving state on a steep road surface, a slipping state, etc.). An electric vehicle that executes release relaxation control is disclosed. In addition, the restriction relaxation condition may be, for example, a condition in which the cumulative number of executions of counting one value each time execution of a process for relaxing the motor torque restriction is less than a predetermined number, The time interval from the relaxation of the current motor torque to the relaxation of the current motor torque is a predetermined time or more, or from the relaxation of the previous motor torque restriction to the relaxation of the current motor torque restriction It is stated that the vehicle travel distance can be a condition that is equal to or greater than a predetermined distance.

JP 2004-324613 A Japanese Patent Laying-Open No. 2005-312187

  However, since the apparatus of Patent Literature 1 needs to estimate the motor temperature in all paths, the calculation load is large, and the output limit and cooling of the electric motor are executed before the motor temperature rises. If there is a change, or if the calculation conditions such as the vehicle speed change, there is a high possibility of unnecessary torque limitation, and there is room for improvement from the viewpoint of balancing uphill climbing performance and protection of the electric motor. .

  Further, even with the electric vehicle of Patent Document 2, it is considered that the climbing performance cannot be sufficiently satisfied in some cases. As described above, in the method of determining the relaxation condition based on the number of executions of relaxation and the execution interval, etc., for example, when climbing is finished, the desired drive control is performed when traveling uphill. It may not be possible to execute.

  The objective of this invention is providing the drive control apparatus of the vehicle which can improve an uphill running performance while suppressing the overheating of the electric drive system containing an electric motor.

A vehicle drive control device according to the present invention is provided in a vehicle including an electric motor that drives the vehicle, temperature detection means that detects the temperature of an electric drive system that includes the electric motor, and a navigation device that acquires vehicle position information. a mounted the drive controller, and the limiting means for the temperature of the electric drive system to limit the load factor of the motor when the predetermined temperature or higher, and have groups Dzu information of the navigation apparatus, at least from the current position to the destination Obtaining means for obtaining the remaining distance and the road gradient;
When the temperature of the electric drive system has reached a predetermined temperature, the remaining distance and the road gradient obtained, and have groups Dzu the predetermined predetermined release criterion is, the temperature of the electric drive system before reaching the destination point An estimation means for estimating whether or not the short-term guaranteed temperature required in advance as a temperature at which the motor can be used for a short time is higher than the predetermined temperature, and the temperature of the electric drive system reaches the short-term guaranteed temperature. when non to have been estimated, possess a restriction release means for releasing the load factor limiting by limiting means, and estimation means for each road gradient running of the vehicle is assumed, short-term guarantee from the predetermined temperature of the electric drive system Including a threshold map that defines each threshold of the remaining distance that causes a temperature rise up to the temperature, and provides a road gradient acquired by the acquiring means and a threshold of the remaining distance obtained from the threshold map by the acquiring means By comparing the remaining distance to be acquired, if the latter is small, the temperature of the electric drive system and estimates not reach the short-term guarantee temperature.

  According to the above configuration, even when the temperature of the electric drive system including the electric motor reaches a predetermined temperature at which the load factor restriction is started, the load information is obtained from the navigation information without executing the load factor restriction uniformly during climbing. Protection and climbing of motors, etc. by estimating whether the temperature of the motor, etc. reaches a short-term guaranteed temperature higher than the predetermined temperature before reaching the destination point based on the remaining climbing distance and road gradient It is possible to achieve both improvement in running performance. That is, when it is estimated by the estimation means that the temperature of the motor or the like reaches the short-term guaranteed temperature, it is possible to perform normal load factor limitation to suppress overheating of the motor or the like, while the temperature of the motor or the like is It is estimated that the short-term guaranteed temperature will not be reached, and if the temperature rises only for a short time that does not cause a problem from the viewpoint of durability of the motor, etc., the load factor limit can be canceled and the climbing performance can be prioritized. .

  According to the above configuration, it is possible to perform highly accurate estimation of the rotating electrical machine temperature in consideration of the road gradient and the remaining distance, and it is possible to achieve both protection of the electric motor and the like and improvement of the climbing performance at a higher level. .

  In addition, when the temperature of the electric drive system reaches a predetermined temperature, the temperature increase rate calculating means for calculating the rate of increase of the temperature of the electric drive system, and the threshold value of the threshold map is changed based on the calculated temperature increase rate. It is preferable to have fluctuating means.

  According to the above configuration, the estimation accuracy of the estimation unit is further improved. That is, the temperature increase rate of the electric motor or the like varies depending on the road conditions and driving conditions up to the current point, and also affects the temperature increase in the remaining travel. Therefore, if the threshold value is changed based on the rate of temperature rise, the estimation criterion becomes more accurate.

  In addition, the limiting means includes a first limit map that defines a load factor limit value that is greater than or equal to a predetermined temperature and less than the short-term guaranteed temperature, and a second limit that defines a load factor limit value that is greater than or equal to the short-term guaranteed temperature. And the restriction release means releases the load factor restriction by the restriction means when it is estimated that the temperature of the electric drive system does not reach the short-term guaranteed temperature, and restricts the load factor based on the second restriction map. Is preferably performed.

  According to the above configuration, even when the load factor restriction based on the first restriction map by the restriction means is released, the driving state changes due to an increase in the vehicle speed or the like, and the temperature of the motor or the like becomes the short-term guaranteed temperature. When it reaches, it becomes possible to perform load factor restriction based on the second restriction map. Therefore, even when an unexpected situation such as a drastic change in the assumed operating state occurs, it is possible to more effectively protect the motor and the like.

  According to the vehicle drive control device of the present invention, it is possible to suppress the overheating of the electric motor and the like and improve the climbing performance. In other words, even when the temperature of the electric motor etc. rises and reaches the temperature at which the load factor restriction starts, there is a problem from the viewpoint of the durability of the electric motor etc. When it is estimated that the temperature rises only for a short time that does not occur, the load factor restriction can be canceled to give priority to the climbing performance. On the other hand, when it is not estimated that the temperature rises only for a short period of time, it is possible to reliably suppress overheating of the electric motor or the like by executing a normal load factor limitation.

  Embodiments according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a drive control apparatus according to an embodiment of the present invention. FIG. 2 is a diagram illustrating first and second load factor restriction maps, and FIG. 3 is a diagram illustrating a threshold map.

  As shown in FIG. 1, a vehicle on which the driving force control device 10 is mounted includes an electric motor 11 that outputs power to a driving shaft (not shown) to drive the vehicle, a battery 12 that supplies electric power to the electric motor 11, And an inverter 13 that converts DC power from the battery 12 into three-phase AC power and supplies it to the electric motor 11. Examples of the vehicle on which the drive control device 10 is mounted include an electric vehicle that is driven only by the electric motor 11, a hybrid vehicle that is driven by using at least one of the electric motor 11 and an engine (not shown) as a drive source.

  The driving force control device 10 has a function of controlling the torque of the electric motor 11 in accordance with an input torque command or the like. Torque control of the electric motor 11 is performed by turning on / off the switching element of the inverter 13 and adjusting the power supplied to the electric motor 11. The drive control device 10 outputs the torque requested according to the driver's accelerator operation or the like when the electric motor 11 is in a normal state, i.e., not in an overheated state. Limit output torque by rate limiting. Generally, when the electric motor 11 is in a normal state, the load factor is set to 100%, and when the motor temperature is in an overheated state, the load factor is limited. The load factor is a motor torque limiting rate, and the torque obtained by multiplying the rated torque of the electric motor 11 by the load factor is the output torque.

  The vehicle to which the drive control device 10 is applied includes a motor temperature sensor 14 that detects the temperature of the electric motor 11, a vehicle speed sensor 15 that detects the speed of the vehicle, and a navigation system 16 that acquires vehicle position information. . In addition, various sensors such as a current sensor, a rotation speed sensor, and a temperature sensor (not shown) can be mounted. Known sensors can be used as these sensors.

  The above-mentioned various sensors are connected to the drive control device 10, and information from these sensors is input. The drive control device 10 is also connected to the navigation system 16, and vehicle information such as the remaining distance from the current location to the destination location, road gradient, and the like is acquired by the acquisition unit 22 described later. Specifically, these pieces of information are input via an input port (not shown), and a control command signal for the inverter 13 is output from the drive control device 10 via an output port (not shown).

  As shown in FIG. 1, the drive control device 10 includes a first load factor restriction map 17 that defines a limit load factor at a predetermined temperature or more and less than a short-term guaranteed temperature, and a second load that defines a limit load factor at or above a short-term guaranteed temperature. A storage means 20 for storing the rate limit map 18 and the threshold map 19 is provided. Further, the storage means 20 temporarily or permanently stores control parameters, control programs, information from each sensor, and the like. The storage unit 20 is, for example, a memory and is connected to each unit to be described later, and the drive control device 10 executes load factor control based on information such as a stored map.

  Further, the drive control device 10 includes a limiting unit 21 that limits the load factor of the electric motor 11 when the temperature of the electric motor 11 is equal to or higher than a predetermined temperature. The limiting means 21 executes load factor limitation based on the first load factor limitation map 17 shown in FIG. The first load factor restriction map 17 is a map that defines the maximum load factor at each motor temperature, and the maximum load factor is described as a constant value (hereinafter, 100%) until the motor temperature reaches a predetermined temperature (Tlim1). The maximum load factor decreases as the motor temperature rises above the predetermined temperature (Tlim1). Here, the predetermined temperature (Tlim1) is a temperature at which the load factor restriction is started, is determined from the viewpoint of protection of the electric motor 11, and the durability of the electric motor 11 is maintained when the temperature is maintained for a certain period of time. This is a temperature that affects the property (hereinafter referred to as long-term guaranteed temperature). Therefore, even if the temperature of the electric motor 11 exceeds the long-term guaranteed temperature (Tlim1) for a short time, the durability of the electric motor 11 is not affected.

  On the other hand, the second load factor limit map 18 is a map that defines a load factor limit value at or above the short-term guaranteed temperature with the short-term guaranteed temperature (Tlim2) as the load factor limit start temperature. Here, the short-term guaranteed temperature (Tlim2) means a temperature at which the use of the electric motor 11 can be continued for a short time. Like the long-term guaranteed temperature (Tlim1) and a threshold value described later, Since it differs depending on the heat dissipation characteristics, it is obtained by executing various simulations and experiments for each electric motor 11. This second load factor restriction map is used by restriction release means 24 described later. Therefore, even when the load factor restriction based on the first load factor restriction map 17 by the restriction means 21 is released, the driving state changes due to an increase in the vehicle speed or the like, and the temperature of the electric motor 11 becomes the short-term guaranteed temperature. When (Tlim2) is reached, it becomes possible to execute load factor restriction based on the second restriction map 18.

  Further, the drive control device 10 includes an acquisition unit 22, an estimation unit 23, and a restriction release unit 24. By these means, even when the temperature of the electric motor 11 reaches the long-term guaranteed temperature (Tlim1) at which the load factor restriction is started during climbing uphill, it is acquired from the navigation system 16 without executing the load factor restriction uniformly. The temperature rise of the electric motor 11 is estimated based on the remaining climbing distance and road gradient, and the climbing performance can be prioritized depending on the traveling state of the vehicle. When the temperature of the electric motor 11 reaches the long-term guaranteed temperature (Tlim1), as a control procedure for limiting the load factor, the processing by the estimating unit 23 (or the acquiring unit 22) is first performed, and then the load factor by the limiting unit 21 is performed. Restriction is executed, and depending on the estimation result by the estimation means 23, the load factor restriction is released.

  The acquisition unit 22 has a function of acquiring the remaining distance from the current point to the destination point and the road gradient based on the information of the navigation system 16. The remaining distance and the road gradient are materials for determining the motor temperature by the estimating means 23 described later, and the distance acquired from the navigation system 16 is usually a distance along the travel route. The road gradient is preferably an average gradient from the current point to the destination point, and the average gradient can be obtained from the altitude and the remaining distance by obtaining the altitudes of both points from the navigation system 16. In addition to the remaining distance and road gradient, the vehicle speed can be acquired from the vehicle speed sensor 15 and the required time from the current point to the destination point can be acquired based on the vehicle speed and the remaining distance. Note that the timing at which the acquisition unit 22 acquires these pieces of information can be the time when the temperature of the electric motor 11 reaches the long-term guaranteed temperature (Tlim1), but can be set to always acquire these pieces of information. it can.

  For example, when the route of the navigation system 16 is set, the destination point means the highest destination point along the route. When the route setting of the navigation system 16 is not made, for example, it can be set as the highest arrival point along the road on which the vehicle is traveling. A destination point is identified for execution. Since the destination point is the highest point of arrival, when traveling on a road with continuous uphills and downhills, the acquisition means 22 basically uses the highest point of arrival as the destination point for each elevation. Is obtained and estimation described later is executed. However, when there is some up / down on the uphill, it is not preferable to perform the estimation every time, and the road gradient threshold for determining whether the up / down is the uphill on which the estimation is performed. Is preferably set. Then, when the threshold value is exceeded, it is recognized as an uphill to be estimated, and acquisition of an average gradient and the like, which will be described later, are executed with the highest arrival point as a destination point. The road gradient can also be obtained from an acceleration sensor, and the maximum gradient from the current point to the destination point can be used as an estimation determination element instead of the average gradient.

  When the temperature of the electric motor 11 reaches the long-term guaranteed temperature (Tlim1), the estimating means 23 is configured to determine the estimated distance before the destination point is reached based on the acquired remaining distance, the road gradient, and a predetermined release criterion. In addition, it has a function of estimating whether or not the temperature of the electric motor 11 reaches the short-term guaranteed temperature (Tlim2). Specifically, the estimation means 23 uses the threshold map 19 shown in FIG. 3 as a predetermined release criterion. The threshold value map 19 shown in FIG. 3 shows each threshold value of the remaining distance that causes the temperature of the electric motor 11 to rise from the long-term guaranteed temperature (Tlim1) to the short-term guaranteed temperature (Tlim2) for each road gradient on which vehicle travel is assumed ( (Threshold line).

  The estimation unit 23 compares the remaining distance acquired by the acquiring unit 22 with the remaining distance that is the threshold value of the threshold map 19 in the acquired road gradient, and if the acquired remaining distance is smaller, that is, the threshold value If there is a remaining distance point based on the acquired data in the B region on the origin side that does not exceed the line, it is estimated that the temperature of the electric motor 11 does not reach the short-term guaranteed temperature (Tlim2). On the other hand, if the acquired remaining distance is larger, that is, if there is a remaining distance point based on the acquired data in the area A exceeding the threshold line, the temperature of the electric motor 11 is the short-term guaranteed temperature (Tlim2). ). When such an estimation is made, the load factor restriction based on the first load factor restriction map 17 by the restriction means 21 is executed as usual. Note that the threshold line varies depending on the size and heat dissipation characteristics of the electric motor 11 and is thus obtained by performing various simulations and experiments for each electric motor 11. In addition, although the threshold line can obtain | require the output condition of motor torque as rated torque, it prescribes | regulates several threshold lines (for example, 70%, 80%, 90% etc. of rated torque) according to each motor torque. Thus, the threshold line to be applied can be changed depending on the motor torque when the estimation by the estimating means 23 is started. Further, the estimation means 23 can be activated by the user at an arbitrary timing, and an OFF setting can be provided.

  The restriction releasing unit 24 has a function of releasing the load factor limitation by the limiting unit 21 when it is estimated that the temperature of the electric motor 11 does not reach the short-term guaranteed temperature (Tlim2). Therefore, when the estimation unit 23 is set, when the temperature of the electric motor 11 reaches the long-term guaranteed temperature (Tlim1), estimation by the estimation unit 23 is executed prior to load factor limitation by the limitation unit 21. . The restriction canceling unit 24 can cancel the load factor limitation by the limiting unit 21 and set it so that the load factor limitation is not performed. However, from the viewpoint of protection of the electric motor 11, the limitation canceling unit 24 is replaced with the first load factor limiting map 17. Thus, it is preferable to execute the load factor restriction based on the second restriction map 18. On the other hand, as described above, when it is estimated that the temperature of the electric motor 11 exceeds the short-term guaranteed temperature (Tlim2), as usual, the load factor based on the first load factor restriction map 17 by the restricting means 21. Restriction is enforced.

  The drive control device 10 preferably includes a temperature increase rate calculating unit 25 and a threshold value changing unit 26. The temperature increase rate calculating means 25 has a function of calculating the temperature increase rate of the electric motor 11 when the temperature of the electric motor 11 reaches the long-term guaranteed temperature (Tlim1). The threshold changing unit 26 has a function of changing the threshold of the threshold map 19 based on the calculated temperature increase rate. The temperature increase rate of the electric motor 11 varies depending on road conditions and driving conditions up to the current point, and also affects the temperature increase in the remaining travel. By providing these means, the estimation accuracy by the estimation means 23 is increased. Further improve.

  In order to calculate the rate of temperature increase, it is necessary to acquire the motor temperature from a time before the current time, and the motor temperature is acquired over time by the acquisition means 22, and will be described later with reference to FIG. Temperature data as shown in (b) is stored in the storage means 20. When the temperature of the electric motor 11 reaches the long-term guaranteed temperature (Tlim1), the temperature increase rate calculating unit 25 reads temperature data from the storage unit 20 and calculates the temperature increase rate. The temperature increase rate can be an average value of the temperature increase gradient over time, and is calculated based on temperature data a predetermined time before the current time, for example. Here, the predetermined time is an appropriate time for realizing the estimation accuracy improvement by the estimation means 23, and specifically, is about several minutes (1 to 10 minutes) before the present time.

  As described above, the threshold changing unit 26 changes the threshold of the threshold map 19 based on the temperature increase rate. For example, when the temperature increase rate is high, it is expected that the temperature increase rate from the long-term guaranteed temperature (Tlim1) to the short-term guaranteed temperature (Tlim2) by continuing traveling is also high, as shown in FIG. The threshold line can be shifted to the B region side which is the origin side. On the other hand, when the rate of temperature rise is low, the temperature hardly rises, so that the threshold line can be shifted to the A region side that is far from the origin.

  The drive control device 10 is a device including a CPU, the storage means 20, an input / output port, and the like, and is configured by a microprocessor or the like. The functions of the units 21 to 26 can be realized by executing software, and specifically, can be realized by executing a control program stored in the storage unit 20. Therefore, each of the above-described means 21 to 26 can be realized by the CPU accessing the storage means 20. Note that the microprocessor or the like constituting the drive control device 10 can be incorporated into a part of a power control unit that controls the electric motor 11 or a vehicle control unit that controls the vehicle.

  The operation of the drive control apparatus 10 having the above configuration will be described in detail below with reference to FIGS. FIG. 4 is a diagram showing the motor temperature (b) and the motor torque (c) with respect to the time axis in the state (a) where the vehicle is traveling uphill at a position close to the destination point which is the highest arrival point, and FIG. It is a flowchart which shows the control procedure of the drive control apparatus 10 in FIG.

  First, it is determined whether or not the temperature (T) of the electric motor 11 is equal to or higher than the long-term guarantee temperature (Tlim1) for the vehicle (FIG. 4A) traveling at the current point (P) (S10). ). As shown in FIG. 4B, when the temperature (T) of the electric motor 11 reaches the long-term guaranteed temperature (Tlim1), the load factor limitation by the limiting means 21 is limited as shown by the dotted line in FIG. The motor torque is started and limited, but in order to improve the climbing performance, estimation processing by the following estimation means 23 and the like are executed prior to the limitation. This procedure can be executed, for example, by the function of the estimating means 23, and the information determined by the estimating means 23 can be transmitted to other means and shared.

  When it is determined that the temperature (T) of the electric motor 11 is equal to or higher than the long-term guaranteed temperature (Tlim1), the altitude (Hp, Hf) of the current point (P) and the destination point (f) from the navigation system 16; The remaining distance (D) from the current point (P) to the destination point (f) is acquired (S11), and the average gradient (θ) is calculated from the acquired elevation information (S12).

  Further, the temperature increase rate of the electric motor 11 is calculated (S13), and the threshold value of the threshold map 19 is changed based on the calculated temperature increase rate (S14). The temperature increase rate is calculated as an average value of the slope from the time when the motor temperature starts to rise to the present time, based on the temperature data shown in FIG. As described above, the threshold value of the threshold map 19 is changed by the threshold value changing unit 26. When the temperature increase rate is high, the threshold value is decreased, and when the temperature increase rate is low, the threshold value is increased. The procedures of S11 to S14 are executed by the functions of the acquisition unit 22, the temperature increase rate calculation unit 25, and the threshold value change unit 26, and the acquired information and the like serve as determination factors for the motor temperature estimation by the estimation unit 23.

  Based on the remaining distance (D) acquired in S11 and S12, the average gradient (θ), and the threshold map 19 changed in S14, the temperature (T) of the electric motor 11 is short when the vehicle travels continuously. Whether the temperature reaches the guaranteed temperature (Tlim2) is estimated by the estimating means 23 (S15). Specifically, as described above, it is determined whether or not the point where the remaining distance (D) and the average gradient (θ) acquired in the threshold map 19 are input exceeds the threshold line, and exceeds the threshold line ( When it is determined that the temperature (T) of the electric motor 11 reaches the short-term guaranteed temperature (Tlim2), the electric motor 11 is determined to determine that it does not exceed the threshold line (B region). It is estimated that the temperature (T) does not reach the short-term guaranteed temperature (Tlim2).

  In S15, when it is estimated that the temperature (T) of the electric motor 11 does not reach the short-term guaranteed temperature (Tlim2), the load factor restriction by the restriction means 21 is not executed, and the second load factor restriction map 18 is used. The load factor restriction is executed (S16). On the other hand, when it is estimated that the short-term guaranteed temperature (Tlim2) is reached, the load factor limitation based on the first load factor limitation map 17 is executed (S17). The procedure of S16 is executed by the function of the restriction release means 24, and the procedure of S17 is executed by the function of the restriction means 21.

  As described above, even when the vehicle travels uphill, as shown in FIG. 4B, even when the temperature (T) of the electric motor 11 reaches the long-term guaranteed temperature (Tlim1) at which the load factor limitation starts, As shown by a thick line in FIG. 4, when the temperature rises for a short time at a level that does not reach the short-term guaranteed temperature (Tlim2), as shown by a dotted line in FIG. Without limiting the motor torque, as shown by the solid line in the figure, by giving priority to the climbing performance, it is possible to achieve both protection of the electric motor 11 and improvement of the climbing performance.

  Even when it is estimated that the motor temperature does not reach the short-term guaranteed temperature (Tlim2) and the load factor restriction by the first load factor restriction map 17 is released, the running temperature changes significantly, etc. When the temperature reaches the short-term guaranteed temperature (Tlim2), the load factor limitation based on the second load factor limitation map 18 is executed. Further, when the driving condition changes significantly, the estimation can be performed again, and the estimation unit 23 is set with a threshold value for invalidating the estimation and executing the estimation again. For example, a certain value such as an increase rate of the vehicle speed or an increase rate of the motor torque can be defined as the threshold value. For example, when a threshold map 19 including a plurality of threshold lines corresponding to each motor torque is used as an estimation criterion, when the motor torque fluctuates beyond the above threshold, the estimation is performed again using another threshold line. It can also be executed.

  Instead of the remaining distance in the threshold map 19, a required time (from the current point to the destination point) can be applied. When the threshold map 19 having the required time as a threshold is used, the acquisition unit 22 acquires the remaining distance from the navigation system 16 and the vehicle speed from the vehicle speed sensor 15 to calculate the required time.

  The drive control device 10 has been described as limiting the load factor of the electric motor 11 based on the temperature of the electric motor 11, but instead of the temperature of the electric motor 11 or in addition to the temperature of the electric motor 11, It is also possible to limit the load factor of the electric motor 11 based on the temperature of the inverter 13.

It is a block diagram which shows the structure of the drive control apparatus which concerns on embodiment of this invention. It is a figure which shows the 1st and 2nd load factor restriction | limiting map. It is a figure which shows the threshold value map which prescribes | regulates each threshold value of residual distance about each road gradient by which vehicle driving | running | working is assumed. It is a figure which shows the time change of motor temperature and a motor torque in the state which the vehicle is traveling uphill in the position near the highest arrival point. 5 is a flowchart showing a control procedure of the drive control apparatus according to the embodiment of the present invention in the situation shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Drive control apparatus, 11 Electric motor, 12 Battery, 13 Inverter, 14 Temperature sensor, 15 Vehicle speed sensor, 16 Navigation system, 17 1st load factor restriction map, 18 2nd load factor restriction map, 19 Threshold map, 20 Storage means 21 limiting means, 22 obtaining means, 23 estimating means, 24 restriction releasing means, 25 temperature rise rate calculating means, 26 threshold value changing means.

Claims (3)

An electric motor for driving the vehicle;
Temperature detecting means for detecting the temperature of the electric drive system including the electric motor;
A navigation device for obtaining vehicle position information;
A drive control device mounted on a vehicle equipped with
Limiting means for limiting the load factor of the electric motor when the temperature of the electric drive system is equal to or higher than a predetermined temperature;
And have groups Dzu information of the navigation device, an acquisition unit for acquiring the remaining distance and the road gradient of at least the current location to the destination point,
When the temperature of the electric drive system has reached a predetermined temperature, the remaining distance and the road gradient obtained, and have groups Dzu the predetermined predetermined release criterion is, the temperature of the electric drive system before reaching the destination point An estimation means for estimating whether or not a short-term guaranteed temperature that is obtained in advance as a temperature at which the use of the electric motor can be continued for a short time is higher than a predetermined temperature;
When it is estimated that the temperature of the electric drive system does not reach the short-term guaranteed temperature, the restriction release means for releasing the load factor restriction by the restriction means,
I have a,
The estimation means is
For each road gradient on which the vehicle is supposed to travel, including a threshold map that defines each threshold of the remaining distance that causes a temperature rise from a predetermined temperature of the electric drive system to a short-term guaranteed temperature,
Compare the remaining distance threshold obtained from the threshold map with the road gradient acquired by the acquisition means and the residual distance acquired by the acquisition means, and if the latter is small, the temperature of the electric drive system is the short-term guaranteed temperature drive control apparatus for a vehicle and estimating not reached. The vehicle drive control device according to claim 1,
A temperature increase rate calculating means for calculating an increase rate of the temperature of the electric drive system when the temperature of the electric drive system reaches a predetermined temperature;
Fluctuation means for varying the threshold value of the threshold map based on the calculated temperature rise rate;
Drive control apparatus for a vehicle, characterized by have a. In the vehicle drive control device according to claim 1 or 2,
The limiting means is
A first limit map that defines a load factor limit value at a predetermined temperature or more and less than the short-term guaranteed temperature with respect to the temperature of the electric drive system; and a second limit map that defines a load factor limit value at or above the short-term guaranteed temperature;
Restriction release means
When it is estimated that the temperature of the electric drive system does not reach the short-term guaranteed temperature, the load factor restriction by the restriction means is canceled, and the load factor restriction is executed based on the second restriction map. Control device.

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