JP2010252409A - Navigation apparatus and method of navigating electric automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a navigation apparatus for setting routes to reliably suppress temperature rise of motors for drive. <P>SOLUTION: An information processor 12 of the navigation apparatus 11 estimates a temperature change of the motor 3 for drive when an electric automobile 1 travels according to a route to a searched destination, and changes the route so that temperature of the motor 3 for drive does not rise to a level, where the performance of the motor 3 deteriorates. Concretely, an integrated value of link costs is calculated based on the link costs and link cost coefficients set for each link to search the route for minimizing the integrated value of the link costs. An integrated value of temperature costs is also calculated, based on temperature costs and temperature cost coefficients set for each link, and the route is changed so that the temperature costs do not exceed a performance deterioration threshold set corresponding to temperature, where the performance of the motor 3 for drive deteriorates. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a navigation device mounted on an electric vehicle that travels by driving wheels by a drive motor and a navigation method for the electric vehicle.

A navigation device mounted on a vehicle usually travels by giving priority to the route that takes the shortest time or distance to reach the destination, giving priority to the selection of toll roads, or considering traffic information. A route that improves efficiency is searched. Further, in general, in an electric vehicle, there is a problem that if the driving motor or a battery that supplies driving power to the motor has heat during traveling, the efficiency is extremely lowered.
Therefore, when the electric vehicle travels along the route searched with priority on traveling efficiency, the driving motor is continuously driven, so that it is assumed that the temperature of the motor or the battery greatly increases. Then, it is considered that there is an influence such as that the speed of the automobile cannot be increased, the running is unstable, and the battery consumption efficiency is lowered.

  For example, Patent Document 1 discloses a motor, an inverter, a motor for driving mounted on an electric vehicle, a battery, and a motor, an inverter, When the battery temperature rises and the next travel section is an uphill road, a technique for disabling the uphill road and setting a detour that can travel to the destination is disclosed.

JP 2005-269878 A

However, just setting a detour as in Patent Document 1 has a limit to the extent that heat generation by a motor or the like can be suppressed, and it cannot be said that an adverse effect associated with a rise in temperature can be reliably avoided.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a navigation device and a navigation method for an electric vehicle that can set a route so as to more reliably suppress a temperature rise of a drive motor. .

  According to the navigation device of the first aspect, the route changing means estimates the temperature change of the driving motor when the electric vehicle travels according to the searched route to the destination, and the temperature of the driving motor is the motor. The route is changed so as not to increase to a level where the performance of the device deteriorates. That is, by estimating and evaluating the temperature change of the driving motor, the path is changed so as to avoid the temperature of the driving motor from rising to a level at which the performance deteriorates. The traveling of the electric vehicle 1 can be continued while maintaining the above.

  According to the navigation device of the second aspect, the route changing means calculates the integrated value of the link cost based on the link cost and the link cost coefficient set for each link, and minimizes the integrated value of the link cost. Search for a route to go. Also, the integrated value of the temperature cost is calculated based on the temperature cost and the temperature cost coefficient set for each link, and the performance deterioration threshold value that is set corresponding to the temperature at which the performance of the drive motor deteriorates is calculated. Change the route so that it does not exceed.

  In other words, if attributes such as road conditions of each link are taken into account, it is possible to estimate how the temperature of the drive motor will change when an electric vehicle travels on that link. It is possible to calculate. If the temperature cost is calculated, the temperature change of the driving motor can be quantitatively evaluated, so that the temperature can be avoided from exceeding the level at which the motor performance deteriorates.

  According to the navigation device of the third aspect, the route changing means changes the route based on the traffic jam information of the route obtained through the traffic information acquiring means. In other words, the road congestion state greatly affects the traveling speed of the automobile and the like. If the temperature change of the drive motor is estimated in consideration of traffic jam information, a route that more reliably suppresses the temperature rise can be selected.

  According to the navigation device of claim 4, the route changing means determines the congestion level to a plurality of levels based on the traffic jam information of each link included in the route, and the link cost coefficient and the temperature cost corresponding to each congestion level. Set the coefficient and calculate the link cost integrated value. In this case, when the temperature cost exceeds the performance deterioration threshold, the link cost is recalculated by reversing the magnitude relation of the link cost coefficient of the link located first. That is, in the case of route calculation aiming at the normal shortest distance or the shortest time, a state where the degree of congestion of the link is high is not desirable. However, when the temperature of the drive motor rises and exceeds the performance deterioration threshold, the situation where the degree of congestion is high and the traveling speed must be reduced is preferable from the viewpoint of suppressing the temperature rise. Therefore, if the link cost is recalculated by reversing the magnitude relationship of the link cost coefficients in such a case, it is easy to select a path that can contribute to suppressing the temperature increase of the drive motor.

  According to the navigation device of the fifth aspect, the route changing means changes the route based on the gradient information given to the route. That is, this route change itself appears to be similar to that of Patent Document 1, but in the present invention, a temperature cost is calculated for the route and the temperature change of the driving motor is estimated, so a more reliable effect is obtained. It is done.

  According to the navigation device of the sixth aspect, the route changing means calculates the link cost by setting the link cost coefficient corresponding to the gradient information of each link included in the route, and the temperature cost exceeds the performance deterioration threshold. If this happens, the link cost is recalculated by reversing the magnitude relationship of the link cost coefficients of the link located earlier. That is, for the same reason as in claim 5, if the link cost is recalculated by reversing the magnitude relationship of the link cost coefficients, a path that can contribute to suppressing the temperature increase of the drive motor is easily selected.

  According to the navigation device of the seventh aspect, the route change means re-calculates the integrated value of the temperature cost. As a result, when the temperature cost is lower than the performance deterioration threshold by a predetermined value, the link cost unit that has been reversed is used. Restore the value setting and perform the recalculation. That is, in this case, there is a slight margin for the load status of the drive motor, so the route search aiming to shorten the travel time or travel distance is performed by returning the link cost coefficient value to the original setting. be able to.

  According to the navigation device of the eighth aspect, the route changing unit sets a limit threshold value that is larger than the performance deterioration threshold value for the temperature cost, and if the temperature cost exceeds the limit threshold value, the route changing unit is positioned ahead of the limit value. The cost calculation is stopped for the link. That is, when the temperature cost exceeds the limit threshold, the node is removed from the selection target and a different path is selected to search for a path that can suppress the temperature rise of the drive motor. .

  According to the navigation device of the ninth aspect, when it is confirmed that the temperature of the drive motor rises, the route changing means gives the cost corresponding to the intersection (that is, the intersection cost) or the intersection itself. The cost is reduced, and the route is changed so as to guide more to the intersection. That is, if there is an intersection in the travel route, the electric vehicle stops when the signal is red, so that the temperature drop of the drive motor can be promoted.

The figure which is one Example of this invention, and shows the whole structure of the drive motor control system Block diagram showing the electrical configuration of the navigation device Flow chart showing control contents of navigation device The flowchart which shows the detail of step S7 of FIG. The figure which shows an example of optimal route search

  An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of the entire drive motor control system. In the electric vehicle 1, a drive motor 3 (FL, FR, RL, RR) is arranged for each of the four wheels 2 (FL, FR, RL, RR), and the driving force of each wheel 2 is individually controlled. It is possible. Each drive motor 3 is supplied with drive power from an independent battery 4 (FL, FR, RL, RR), and the drive motor 3 incorporates a drive circuit such as an inverter circuit. Is given a control command from the motor control device 5.

  The navigation device 11 mounted on the electric vehicle 1 can communicate with the motor control device 5 and transmits control information of the drive motor 3 to the motor control device 5. When the motor control device 5 generates a control command for each drive motor 3 based on the control information, the motor control device 5 outputs it to the drive circuit of each drive motor 3 as described above. The motor control device 5 is adapted to obtain temperature information output from thermometers 6 (FL, FR, RL, RR, temperature sensors) arranged in each drive motor 3. The motor control device 5 also monitors the output voltage and output current of each battery 4 and monitors the temperature with a thermometer (not shown).

  FIG. 2 is a block diagram showing an electrical configuration of the navigation device 11. The navigation device 11 includes an information processing device (route changing means) 12 mainly composed of a microcomputer, a GPS (Global Positioning System) 13 for detecting the current position of the vehicle, a map database (DB) 14, an operation unit 15, External communication device (traffic information acquisition means) 16, for example, a display device (notification means) 17 comprising a color liquid crystal display using TFT (Thin Film Transistor), a speaker (notification means) 18, an in-vehicle sensor unit 19, an outside sensor unit 20 and an in-vehicle communication device 21 and the like.

  The information processing apparatus 12 includes a CPU 12a, a ROM 12b, a RAM 12c, a flash memory 12d, a timer 12e, and the like. The GPS 13 is a receiver for GPS (Global Positioning System) that detects (positions) the current position of the vehicle based on the radio wave transmitted from the artificial satellite. The in-vehicle sensor unit 19 is a vehicle speed sensor, a G sensor for detecting the pitch angle of the vehicle, a gyroscope for detecting the roll angle of the vehicle, a distance sensor for detecting the travel distance of the vehicle, etc. although not shown. Further, for the in-vehicle sensor unit 19, other steering rotation sensors, wheel sensors for the respective drive wheels, and the like may be used. The information processing device 12 detects the current position, traveling direction, speed, travel distance, current time, and the like of the vehicle with high accuracy based on signals from the GPS 13 and the in-vehicle sensor unit 19.

  The map database 14 is data from a map data recording medium that records various data such as road map data, landmark data, map matching data, destination data (facility database), and table data for converting traffic information into road data. It is comprised by the drive device for reading. As the map data recording medium, a large-capacity storage medium such as a DVD is generally used, but a medium such as a memory card or a hard disk device may be used.

  The above road map data includes data such as road shape, road condition (rolling resistance, slope resistance), road width, road name, signal, railroad crossing, building, various facilities, place name, topography, etc., and the road map is displayed. Data to be displayed on the screen of the device 17 is included. Destination data consists of information about transportation facilities such as stations, leisure facilities, accommodation facilities, public facilities, various stores such as retail stores, department stores, restaurants, residences, condominiums, and place names. The data includes data such as the telephone number, address, latitude and longitude, and also includes data for displaying a landmark indicating the facility on the road map on the display device 17 screen. It is configured.

  Although not shown in detail, the operation unit 15 includes a mechanical switch provided near the screen of the display device 17, a touch panel provided on the screen of the display device 17, and a remote control switch. The user (driver) uses the operation unit 5 to input a destination, information necessary for searching for the destination, and various commands for switching the screen and display mode of the display device 17. It is like that.

  The external communication device 16 receives data by wireless communication with various traffic information centers 22 such as VICS (registered trademark) and telematics outside, and can acquire traffic jam information and the like. The display device 17 corresponds to notifying means, and a map around the position of the vehicle is displayed on the screen at various scales, and the current position and the traveling direction of the vehicle are shown superimposed on the display. The current location mark (pointer) is displayed. Further, when searching for a route to the destination, a plurality of searched routes are displayed simultaneously. When the route guidance to this destination is executed, a route guidance screen is displayed. Furthermore, the display device 17 displays an input screen for the user to input information necessary for searching for the destination, search for the destination and setting, various messages, and the like. It has become. The speaker 18 outputs a voice message for route guidance and performs various voice notifications.

Here, the function as the route search means in the information processing apparatus 12 is to automatically calculate a recommended travel route from the starting point (current position) of the vehicle to the destination, and for example, the Dijkstra method is used as the method. It is used.
The vehicle exterior sensor unit 20 is a sensor mainly for detecting the road traffic situation of the host vehicle in real time, and includes, for example, a radar sensor, a laser sensor, a camera unit, and the like. The information processing apparatus 12 grasps the degree of traffic jam by detecting the presence / absence and distance of the vehicle located in front of the host vehicle.

  Next, the operation of the present embodiment will be described with reference to FIGS. FIG. 3 is a flowchart showing the contents of control executed mainly by the information processing apparatus 12 of the navigation apparatus 11 with respect to the portion related to the gist of the present invention. The information processing device 12 measures the current position of the electric vehicle 1 using the GPS 13 or the in-vehicle sensor unit 19 (step S1), and receives the traffic information of the guide route using the external communication device 16 (step S2). Then, it is determined whether there is a destination set by the user (step S3). If there is a destination (YES), the destination is determined (step S4), and the temperature (initial temperature) of the drive motor 3 measured by the thermometer 6 is acquired (step S5). Then, a guide route that is optimal for suppressing the temperature rise of the drive motor 3 is searched (step S6).

If the destination is not set in step S3 (NO), the information processing apparatus 12 predicts the traveling direction of the electric vehicle 1 by the in-vehicle sensor unit 19 (step S8), and the drive motor is the same as in step S5. 3 is obtained (step S9), and a route search is performed along the traveling direction (road route search, step S10).
When the route search is performed in step S6 or S10, whether or not the temperature of the driving motor 3 at that time is higher than a temperature obtained by subtracting a predetermined margin α degree from a preset operating limit temperature of the motor. Is determined (step S7). If [(limit temperature−α) ≧ motor temperature] (NO), the process ends as it is, and if [(limit temperature−α) <motor temperature] (YES), the process returns to step S3.

  FIG. 4 is a flowchart showing the processing contents of the optimum route search in step S6. In general, in the Dijkstra method used for navigation route search, route calculation is performed so that the link cost is minimized. In this embodiment, the electric vehicle 1 travels along each link in accordance with the link cost. The “temperature cost” is set according to the level at which the temperature of the driving motor 3 is estimated to change, and the integrated value of the temperature cost is also calculated.

  In FIG. 4, first, link cost and temperature cost are initialized (step S11). Then, the link cost integrated value sum [0] at the starting point (departure point) is set to “= 0”, and the temperature cost integrated value Temp [0] is set to the temperature measured in step S5 by a predetermined coefficient β. The multiplied value is set as an initial value (step S12). The subsequent steps S13 to S32 become a main loop that loops until the search to the end point (destination) is completed, that is, while sum [N-1] =-1 (unsearched).

  In the following step S14, the variable min that holds the minimum value is set to the maximum value INT_MAX. Subsequent steps S15 to S30 become a sub-loop that loops (i = 0, 1, 2,..., N−1) while there are unsearched nodes. In step S16, it is determined whether or not the current node i has been searched, that is, whether sum [i] ≠ −1. If it has been searched (YES), the unsearched node loop of steps S17 to S29 is executed. If the search has not been completed (NO), the process leaves the unsearched node loop, increments the pointer i, and goes around the searched node loop.

  In step S18, it is determined whether or not the current node j is unsearched, that is, sum [j] = − 1. If not searched (YES), it is determined whether or not the nodes i and j are connected ( Step S19). When nodes i and j are connected, graph [i] [j] is assigned a predetermined link cost (≠ 0) (YES), so the information control device 12 passes through the external communication device 16. The traffic information about the link [i] [j] is acquired (step S20).

Then, it is determined whether or not the temperature cost Temp [i] when the electric vehicle 1 reaches the node i exceeds the performance deterioration temperature cost value (performance deterioration threshold) of the drive motor 3 (step S21). The temperature cost Temp [i] is calculated in step S24 described later. In step S24, Temp [j] is calculated, but at this time, the previously calculated is Temp [i]. Further, the “performance deterioration temperature cost value” is a temperature cost value that is estimated to deteriorate the motor performance as the temperature of the drive motor 3 increases.
Here, when a plurality of drive motors 3 are provided as in the electric vehicle 1, the temperature cost may be calculated individually for all the drive motors 3, or the temperature cost only for any one drive motor 3. May be calculated.

  If the temperature cost Temp [i] does not exceed the performance deterioration temperature cost value in step S21 (NO), the link cost coefficient T is set as usual (step S23). On the other hand, when the temperature cost Temp [i] exceeds the performance deterioration temperature cost value (YES), the setting of the link cost coefficient T is switched to one corresponding to the deterioration temperature range (step S22).

The link cost coefficient T is used when calculating an integrated value of the link cost in steps S26 and S27 described later. And a value is changed according to the congestion condition of link [i] [j] based on the traffic information acquired by step S20. For example, if the degree of congestion is discriminated into three stages of “smooth”, “crowded”, and “congested”, for example, “normal” = 1, “congested” = 2, “congested” = when “normal” is set in step S23. 4 In the case of the “deterioration temperature range” setting in step S22, “smooth” = 2, “congestion” = 1, and “congestion” = 4.
In other words, with normal navigation, it is possible to reduce the travel time to the destination by guiding the user to drive on a road with low traffic and “good”, so link from “good” to “traffic”. The value of the cost coefficient T is set from small to large. On the other hand, in step S22, it is desirable to guide the traveling state of the electric vehicle 1 in the direction of decreasing the temperature of the drive motor 3. Therefore, the magnitude relationship of the link cost coefficient T is reversed between “smooth” and “congestion”.

  Further, once step S22 is executed, the state is stored by a flag or the like, and when it is determined “NO” in step S21, the above flag is checked. If the flag is set, the integrated value is obtained. If Temp [i] is lower than the performance deterioration temperature cost value by a predetermined value γ, step S23 is executed. If the decrease is within the predetermined value γ, the setting in step S22 is continued. good. In such a case, it is possible to more reliably prevent the integrated value Temp [i] from exceeding the performance deterioration temperature cost value again within a short time. In addition, it is possible to perform a route search aimed at shortening the travel time or travel distance.

In the subsequent step S24, the temperature cost Temp [j] at the time when the node j is reached is calculated by the following equation.
Temp [j] = Tm * graph [i] [j] + Temp [i] (1)
However, Tm is a temperature cost coefficient, and “smooth” = 4, “congestion” = 1, and “congestion” = − 1 according to the degree of congestion on the road. That is, in the case of “smooth”, the value is increased because the temperature of the drive motor 3 increases, and in the case of “congestion”, the temperature is expected to decrease. The equation (1) is obtained by adding the cost of the link [i] [j] multiplied by the temperature cost coefficient Tm to the temperature cost Temp [i] at the time of reaching the node i. The temperature cost Temp [j] is obtained.

Next, it is determined whether or not the temperature cost Temp [j] exceeds the limit temperature cost value (limit threshold) of the drive motor 3 (step S25). The “limit temperature cost value” is a temperature cost value that is estimated to reach an operation limit when the temperature of the drive motor 3 rises. If the temperature cost Temp [j] does not exceed the limit temperature cost value (NO), the link cost integrated value at that time is calculated by the following equation:
sum [i] + T * graph [i] [j] (2)
It is determined whether or not the integrated value is smaller than the minimum value min at that time (step S26). If it is smaller than the minimum value min (YES), the integrated value is set to a new minimum value min (step S27).

  In subsequent step S28, the pointer of node i is set to snode, and the pointer of node j is set to enode. If "NO" is determined in steps S18, S19, and S26, and if "YES" is determined in step S25, the pointer j is incremented and an unsearched node loop is made.

When exiting the searched node loop, the minimum cost integrated value min at that time is held, and the connection of the nodes in the searched route is stored.
sum [enode] = min
from [enode] = snode
(Step S31). Then go around the main loop. Finally, the end point is already searched,
sum [N−1] ≠ −1
Then, after exiting the main loop, what is stored in sum [enode] and from [enode] at that time becomes the link list of the optimum route showing the minimum link cost integrated value.

FIG. 5 is a diagram showing an example when an optimum route is searched according to the flow of FIG. The number inside the circle is a node, [1] is the departure place, and [9] is the destination. The link between each node indicates the link cost and the degree of congestion obtained from the traffic information. And each node is in the middle of the route search,
(Link list, temperature cost, link cost)
Is shown. Regarding the temperature cost, for example, the normal range is “0 to 14”, the performance deterioration range is “15 to 22” (that is, “14” is the performance deterioration temperature cost value), and the limit range is “23 to” (that is, “22” "Is set as the limit temperature cost value).

For example, when going from node [1] to [2], the link cost is “3” and the degree of congestion is “smooth”, so the link cost coefficient T is “1” and the temperature cost coefficient Tm is “4”. It becomes. As a result, each value in the node [2] is (1-2, 12, 3). Also, when going from node [1] to [3], the link cost is also “3”, but the congestion degree is “congestion”, so the link cost coefficient T is “2” and the temperature cost coefficient Tm is “ −1 ”. As a result, each value in the node [3] is (1-3, 0, 12). When the integrated value of the temperature cost is a negative value, it is set to “0”.
Then, when going from node [2] to [4], the temperature cost is “24” exceeding the limit range, so this link is not selected and the case going to node [5] is calculated. Since the degree of congestion is “congested”, the temperature cost is “15”.

When reaching node [7], there are two linked lists, L1 [1-2-5-7] and L2 [1-3-5-7], but the temperature cost of the former L1 exceeds the degradation temperature range. “18”. Therefore, when going to the destination node [9], the link cost coefficient of “congestion” is set to “1”. On the other hand, the latter L2, which is in the normal range, is calculated by setting the link cost coefficient to “2”.
At the time of reaching node [8], there are three link lists, L3 [1-2-5-8], L4 [1-3-5-8], and L5 [1-2-6-8]. . Since the temperature cost of L3 is “23” which exceeds the limit range, it is terminated here.

  At the time of reaching the destination node [9], there are four link lists L1, L2, L4, and L5, but the temperature costs of L4 and L5 are “24” and “27” exceeding the limit range. ing. Further, since the temperature cost of L1 is “22” exceeding the performance deterioration range, the route of the link list L2 is finally selected.

  As described above, according to the present embodiment, the information processing device 12 of the navigation device 11 performs the driving motor measured by the thermometer 6 at the start of traveling when the electric vehicle 1 travels according to the route to the searched destination. 3, that is, when the initial value is determined by multiplying the temperature by a predetermined coefficient, the temperature change of the driving motor 3 is estimated, and the temperature of the driving motor 3 is a level at which the performance of the motor 3 deteriorates. The route was changed so as not to rise. Therefore, it is possible to continue the travel of the electric vehicle 1 while maintaining the performance of the drive motor 3.

In this case, the information processing apparatus 12 calculates an integrated value of the link cost based on the link cost and the link cost coefficient set for each link, and searches for a route that minimizes the integrated value of the link cost. Further, an integrated value of the temperature cost is also calculated based on the temperature cost and temperature cost coefficient set for each link, and the performance cost is set corresponding to the temperature at which the performance of the drive motor 3 deteriorates. Change the route so that the cost value is not exceeded.
In other words, if attributes such as road conditions of each link are taken into account, it can be estimated how the temperature of the drive motor 3 changes when the electric vehicle 1 travels on the link. Since it is possible to calculate the cost, if the integrated value of the temperature cost is calculated, the temperature change of the drive motor 3 can be quantitatively evaluated, and the estimated temperature is avoided so as not to exceed the performance degradation temperature cost value it can.

  Further, the information processing apparatus 12 changes the route based on the traffic jam information of the route obtained via the external communication device 16. That is, the congestion state of the road greatly affects the traveling speed of the automobile and the like, and if the temperature change of the driving motor 3 is estimated in consideration of traffic jam information, a route that more reliably suppresses the temperature rise can be selected. Specifically, based on the traffic jam information, the degree of congestion is discriminated into three levels of “normal”, “crowded”, and “traffic jam”, and the link cost coefficient corresponding to each congestion level is set and the link cost integrated value Calculate In this case, when the temperature cost exceeds the performance degradation temperature cost value, the link cost is recalculated by reversing the size relationship of the link cost coefficient of the link located earlier, so the temperature rise of the drive motor 3 is increased. A route that can contribute to the suppression is easily selected.

Further, as a result of recalculating the integrated value of the temperature cost, the information processing apparatus 12 uses the setting of the reversed link cost coefficient value when the temperature cost is lower than the performance deterioration temperature cost value by a predetermined value γ. Since the calculation is further recalculated, it is possible to perform a route search aiming at shortening the travel time or travel distance when there is a slight margin in the load status of the drive motor 3.
In addition, the information processing device 12 sets a limit temperature cost value that is greater than the performance deterioration value for the temperature cost, and if the temperature cost exceeds the limit temperature cost value, Since the cost calculation is stopped, the previous path including the node is excluded from the selection targets, and the path that can more reliably suppress the temperature rise of the drive motor 3 is selected.

In addition, you may comprise as follows.
-The route is changed based on the gradient information given to the route of the map data. That is, this route change itself appears to be similar to that of Patent Document 1, but in the present invention, the temperature cost of the route is calculated and the temperature change of the driving motor 3 is estimated. can get.

  A link cost coefficient corresponding to the gradient information of each link included in the path is set to calculate the link cost, and when the temperature cost exceeds the performance degradation temperature cost value, the link cost coefficient of the link located first The link cost is recalculated by reversing the size relationship. Also in this case, a path that can contribute to suppressing the temperature increase of the drive motor 3 is easily selected as in the above-described embodiment.

  When a tendency for the temperature of the drive motor 3 to rise is confirmed, the route is such that the cost corresponding to the intersection (intersection cost) or the link cost given to the intersection itself is lowered and more guidance is provided at the intersection. To change. That is, if there is an intersection in the travel route, the electric vehicle 1 stops when the signal is red, so that the temperature drop of the drive motor 3 can be promoted.

The present invention is not limited to the embodiments described above or shown in the drawings, and the following modifications or expansions are possible.
The degree of congestion may be determined as 2 levels or 4 levels or more. Further, as traffic information, other road construction information, accident occurrence information, or the like may be used. Moreover, it is not always necessary to use traffic information.
The setting of the link cost coefficient and the temperature cost coefficient is an example, and may be appropriately changed according to individual design. The same applies to the temperature cost value in the performance deterioration temperature range and the limit range.
The outside sensor unit 20 may be used as a traffic information acquisition unit.

The “road route search” in step S10 may be performed in accordance with the processing shown in FIG.
If “YES” is determined in step S7 and step S6 or S10 is re-executed, the temperature estimation of the drive motor 3 based on the temperature cost may have been estimated higher. Therefore, in this case, the link cost coefficient and / or the temperature cost coefficient may be changed to be set lower. That is, the temperature estimation result may be corrected based on the temperature of the drive motor 3 measured by the thermometer 6.

The initial value for estimating the temperature of the drive motor 3 may be determined based on, for example, the measurement result of a temperature sensor that detects the temperature of the engine room or the outside air temperature.
The drive motor 3 is not necessarily provided corresponding to all of the four wheels 2, and one or more drive motors are sufficient.
You may apply to the hybrid type electric vehicle comprised by a combination with a gasoline engine.

  1 is an electric vehicle, 2 is a wheel, 3 is a drive motor, 4 is a battery, 5 is a motor control device, 6 is a thermometer (temperature sensor), 11 is a navigation device, 12 is an information processing device (path changing means), Reference numeral 16 denotes an external communication device (traffic information acquisition means).

Claims (18)

In a navigation device mounted on an electric vehicle that travels by driving wheels by a drive motor,
When the electric vehicle travels according to the route to the searched destination, the temperature change of the drive motor is estimated, and the route is set so that the temperature of the drive motor does not rise to a level at which the performance of the motor deteriorates. A navigation device comprising route changing means for changing.   The route changing means calculates a link cost integrated value based on a link cost and a link cost coefficient set for each link, searches for a route that minimizes the link cost integrated value, and sets for each link. An integrated value of the temperature cost is also calculated based on the temperature cost and the temperature cost coefficient so that the temperature cost does not exceed a performance deterioration threshold set corresponding to a temperature at which the performance of the driving motor deteriorates. The navigation device according to claim 1, wherein the route is changed. Provide traffic information acquisition means to acquire road traffic information from outside,
The navigation device according to claim 2, wherein the route changing unit changes the route based on traffic congestion information of the route obtained through the traffic information acquisition unit. The route changing means determines congestion levels to a plurality of levels based on congestion information of each link included in the route, sets a link cost coefficient corresponding to each congestion level, and calculates an integrated value of link costs. With
The link cost is recalculated by reversing the magnitude relationship for at least a part of the link cost coefficient of the link located earlier when the temperature cost exceeds the performance deterioration threshold. The navigation device described.   5. The navigation device according to claim 2, wherein the route changing unit changes the route based on gradient information given to the route. 6. The route changing means sets a link cost coefficient corresponding to the gradient information of each link included in the route and calculates a link cost,
6. The link cost is recalculated by reversing the magnitude relationship for at least a part of a link cost coefficient of a link located earlier when the temperature cost exceeds the performance deterioration threshold. The navigation device described.   The route changing means recalculates the integrated value of the temperature cost, and as a result, if the temperature cost is reduced by a predetermined value from the performance deterioration threshold value, the reversed cost coefficient value setting is restored to the original value, and further re-executed. The navigation apparatus according to claim 4 or 6, wherein calculation is performed.   The path changing unit sets a limit threshold value that is greater than the performance degradation value for the temperature cost, and when the temperature cost exceeds the limit threshold value, calculates a cost for a link positioned ahead of the temperature cost. The navigation device according to any one of claims 2 to 7, wherein the navigation device is stopped.   When it is confirmed that the temperature of the driving motor rises, the route changing means lowers the cost corresponding to the intersection or the link cost given to the intersection itself, and guides more to the intersection. The navigation device according to any one of claims 2 to 8, wherein the route is changed. In a navigation method executed by a navigation device mounted on an electric vehicle that travels by driving wheels by a drive motor,
When the electric vehicle travels according to the route to the searched destination, the temperature change of the drive motor is estimated, and the route is set so that the temperature of the drive motor does not rise to a level at which the performance of the motor deteriorates. A method for navigation of an electric vehicle, characterized by changing.   Based on the link cost and link cost coefficient set for each link, a link cost integrated value is calculated, a path that minimizes the link cost integrated value is searched, and the temperature cost and the temperature set for each link are searched. An integrated value of the temperature cost is also calculated based on the cost coefficient, and the path is changed so that the temperature cost does not exceed a performance deterioration threshold set corresponding to a temperature at which the performance of the driving motor deteriorates. The method for navigating an electric vehicle according to claim 10.   12. The electric vehicle navigation method according to claim 11, wherein when the road traffic information is acquired from the outside, the route is changed based on traffic congestion information of the route obtained as the road traffic information. Based on the congestion information of each link included in the route, the degree of congestion is determined at a plurality of levels, a link cost coefficient and a temperature cost coefficient corresponding to each congestion level are set, and an integrated value of the link cost is calculated.
13. The electric vehicle according to claim 12, wherein when the temperature cost exceeds the performance deterioration threshold, the link cost is recalculated by reversing the magnitude relation of the link cost coefficient of the link located earlier. Navigation method.   The navigation method for an electric vehicle according to claim 11, wherein the route is changed based on gradient information given to the route. While setting a link cost coefficient and a temperature cost coefficient corresponding to the gradient information of each link included in the path to calculate the link cost,
15. The electricity according to claim 14, wherein when the temperature cost exceeds the performance deterioration threshold value, recalculation of the link cost and the temperature cost is performed by reversing the magnitude relation of the cost coefficient of the link located earlier. Car navigation method.   As a result of recalculating the integrated value of the temperature cost, when the temperature cost is lower than the performance deterioration threshold by a predetermined value, the inverted cost coefficient value is set back to the original value and further recalculated. The navigation method for an electric vehicle according to claim 13 or 15.   A limit threshold value that is larger than the performance degradation value is set for the temperature cost, and when the temperature cost exceeds the limit threshold value, the cost calculation is stopped for a link located ahead of the temperature cost. The electric vehicle navigation method according to any one of claims 11 to 16.   If a tendency to increase the temperature of the driving motor is confirmed, the cost corresponding to the intersection or the link cost given to the intersection itself is reduced, and the route is changed so as to guide more to the intersection. The navigation method for an electric vehicle according to any one of claims 11 to 17, characterized in that:

Images