JPH10126902A - Display device for electric vehicle - Google Patents

Abstract

(57) [Summary] [Problem] To enable a driver to clearly understand "how much more can be actually run". SOLUTION: The display device 10 has a battery remaining capacity detecting means 18 for detecting a remaining capacity W of a battery 12, and a maximum speed setting means 20 for setting a maximum speed Sm of the electric vehicle 16.
And the remaining battery charge detecting means 1 when the vehicle is fully opened at the maximum speed Sm set by the maximum speed setting means 20.
8, the remaining travel time T obtained from the remaining capacity W detected
And a display means 24 for displaying the remaining travel time T calculated by the remaining travel time calculation means 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device provided in an electric vehicle such as an electric wheelchair or an electric tricycle which runs by driving a motor with electric power of a battery, and which displays information relating to the remaining capacity of the battery.

[0002]

2. Description of the Related Art The remaining capacity, which is the current capacity [Ah] stored in a battery after charging, naturally decreases as the electric vehicle travels. Therefore, the electric vehicle is provided with a display device for notifying the driver of the remaining capacity. In the conventional display device, the remaining capacity itself is displayed. For example, in the display device disclosed in Japanese Unexamined Patent Application Publication No. 8-79903, five lamps are turned on when fully charged, and are turned off one by one as the remaining capacity decreases.

[0003]

However, in the conventional display device, it is difficult to judge from the displayed information "how much more traveling is actually possible (hereinafter referred to as" remaining traveling possible condition ")". there were. This is because, even if the information displayed on the conventional display device is the same, the remaining traveling possible condition may be different depending on the traveling state of the electric vehicle and the like.

[0004]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a display device for an electric vehicle, which allows a driver to clearly understand the condition for remaining running.

[0005]

The inventor of the present invention has conducted research on "how to make it possible for the driver to clearly understand the remaining running conditions" as a result of the repeated studies, and as a result, set the maximum speed. It was found that the remaining capacity should be displayed as the remaining running time when the vehicle is fully opened.

The "remaining running time" is set for the following reason. (1) Usually, a driver carries a wristwatch, for example, and manages his / her own behavior depending on time. So if you know how many hours you can actually drive,
It is easy to plan and change actions. (2) The calculation of the remaining travel time is extremely simple as described later.

The reason for limiting the case to "when the vehicle is fully opened at the set maximum speed" is as follows. (1) Assuming the remaining traveling time when traveling at the current speed, the remaining traveling time greatly increases and decreases according to the speed, and becomes infinite when the vehicle stops. Therefore, it is difficult to grasp the condition for remaining traveling. (2) Actually, the vehicle travels at or below the maximum speed, so that the remaining traveling time has some allowance.

FIG. 1 is a functional block diagram showing a display device according to the present invention. Hereinafter, description will be made based on this drawing.

The display device 10 according to the present invention comprises a battery 1
Electric vehicle 16 that runs by driving the motor 14 with the power of 2
It is provided in. The display device 10 includes: (a) a remaining battery capacity detection unit 1 for detecting the remaining capacity W of the battery 12;
8, (b) the maximum speed setting means 20 for setting the maximum speed Sm of the electric vehicle 16, and (c) the remaining battery capacity detection means when the vehicle is fully opened at the maximum speed Sm set by the maximum speed setting means 20. A remaining travel time calculating means 22 for calculating the remaining travel time T obtained from the remaining capacity W detected at 18; and (d) a display means 24 for displaying the remaining travel time T calculated by the remaining travel time calculating means 22. And with.

The remaining running time calculating means 22 can be realized, for example, as a function of a microcomputer. Assuming that the current consumption when the vehicle travels fully at the maximum speed Sm set by the maximum speed setting means 20 is I, the remaining travel time calculation means 22
Calculates the remaining running time T by the following basic arithmetic expression. T [h] = W [Ah] / I [A] ... The relationship between the maximum speed Sm and the current consumption I is experimentally determined in advance and stored in the memory of the microcomputer.
Further, for example, by multiplying the right side of the arithmetic expression by a correction coefficient or by adding or subtracting a constant value to the right side of the arithmetic expression, the arithmetic expression may be modified to calculate the remaining travel time T. Thus, the remaining running time T can be calculated very easily.

The maximum speed setting means 20 is various switches which can manually output an arbitrary analog amount or digital amount. The remaining battery capacity detecting unit 18 is divided into a sensor unit 181 and a calculating unit 182. Sensor unit 181
Is, for example, a current sensor that detects the output current of the battery 12, a current sensor that detects the output voltage of the battery 12,
It comprises a temperature sensor for detecting the temperature of the battery 12 and the like. The calculation unit 182 can be realized, for example, as a function of a microcomputer, and calculates the remaining capacity W from the output current, output voltage, and temperature of the battery 12 obtained by the sensor unit 181. The calculation formula can be obtained experimentally,
It is stored in the memory of the microcomputer. The display means 24 is a liquid crystal display, an LED display, or the like.

The electric vehicle 16 is provided with operation means 26 for the driver to instruct the direction and speed, and control means 28 for supplying electric power from the battery 12 to the motor 14. The control means 28 supplies electric power so that the direction and the speed are instructed by the operation means 26 within the range of the maximum speed Sm set by the maximum speed setting means 20.

[0013]

FIG. 2 is a configuration diagram showing one embodiment of a display device according to the present invention in more detail. Less than,
A description will be given based on FIG. 1 and FIG. However, in FIG. 2, the same parts as those in FIG.

The display device 10 comprises a main controller 30 having a built-in remaining battery charge detecting means 18 and a remaining running time calculating means 22, a maximum speed setting means 20, and a display means 2.
4 is provided. The main controller 30
Microcomputer, motor drive circuit, voltage sensor,
The remaining battery capacity detection means 18, the remaining travel time calculation means 22, and the control means 28 are realized by components such as a current sensor. The maximum speed setting means 20 is a manual rotary type sliding resistor, and can set the maximum speed Sm in a stepless manner within a range of 2 to 6 [km / h]. The display means 24 includes a seven-segment LED 241 for displaying two digits and a bar LED 242 for displaying five points. 7 segment LED24
1 indicates the remaining running time T, and the bar LED 242 indicates the remaining capacity W.

The electric vehicle 16 is an electric wheelchair. The battery 12 is a lead battery, and has a temperature sensor 181t attached. The motor 14 includes a left wheel motor 14L, a right wheel motor 14R, a motor 14L,
A rotary encoder 15L for detecting the rotation speed of the 14R,
15R. The operation means 26 is a John stick controller, and a sliding resistor 26 whose sliding contact is moved by an operation knob and a gimbal mechanism (not shown).
L, 26R. Sliding resistors 26L, 26R
It is in accordance with the tilting angle and the tilting direction of the operation knob, and outputs the motor 14L, the accelerator signal A _L for 14R, the A _R to the main controller 30.

FIG. 3 is a flowchart showing the operation of the main controller 30 relating to the display device 10. FIG.
Is a graph showing the relationship between the speed S and the current consumption I in the electric vehicle 16. FIG. 5 is a chart showing a display example on the display unit 24. Hereinafter, based on FIGS. 2 to 5,
The operation of the main controller 30 relating to the display device 10 will be described.

As shown in FIG. 4, the relationship between the speed S and the current consumption I has been experimentally obtained in advance and stored in the memory of the main controller 30. The consumption current I is a value when the vehicle travels on a flat road at the speed S.

First, a consumed current I corresponding to the maximum speed Sm set by the maximum speed setting means 20 is obtained from FIG. 4 (step 101). Subsequently, the remaining capacity W is detected from the output current, output voltage, and temperature of the battery 12 (Step 102). Subsequently, the arithmetic expression T [h] = W [Ah] / I
The remaining travel time T is calculated according to [A] (step 103). Subsequently, as shown in FIG. 5, the remaining running time T is displayed on the 7-segment LED 241 and the bar LED 2 is displayed.
The remaining capacity W is displayed at 42 (step 104). The operations of steps 101 to 104 are repeated at a predetermined sampling time.

For example, the maximum speed Sm is 6 [km / h],
It is assumed that the remaining capacity W is 7.2 [Ah]. At this time,
The consumption current I corresponding to the maximum speed Sm is shown in FIGS.
[A] is required. Therefore, the remaining running time T is calculated from the calculation formula as 7.2 / 6 = 1.2 [h], and “1.2” is displayed on the 7-segment LED 241. Next, when the maximum speed Sm is switched to 2 [km / h] under this condition, the consumption current I is 3 [A] in the same manner.
Therefore, the remaining running time T is 7.2 / 3 = 2.4.
[H], and “2.4” is assigned to the 7-segment LED 241.
Is displayed.

As shown in FIG. 5, when the remaining running time T is 3 hours or more, the 7-segment LED 241 does not display the remaining running time T. Therefore, when the remaining travel time T falls below a certain level, the display is suddenly started, so that the driver can clearly know that the remaining travel time T has decreased.

The remaining running time T is equal to 30 when the remaining capacity W is full charge.
%, The remaining capacity W is 30%
, "0" is displayed. Therefore, the driver can charge the battery 12 early with the remaining capacity W remaining to some extent, so that damage due to overdischarge of the battery 12 can be prevented.

The main controller 30 determines that the remaining capacity W is 1
When it becomes 0% or less, the display of the 7-segment LED 241 is decremented from "60" by "1" per second while issuing a warning with an intermittent sound of an alarm buzzer (not shown). And
When the display of the 7-segment LED 241 becomes “0”, the alarm buzzer is changed to a continuous sound, and the display of the 7-segment LED 241 blinks while the display of the 7-segment LED 241 remains “0”.
4 is forcibly stopped. As a result, a fixed notice time is given before the forced stop is executed, so that the driver has 60
The electric vehicle 16 can be moved to an appropriate position within seconds. This operation can be repeatedly executed by turning on a power switch (not shown) again. However, when the output voltage of the battery 12 falls below 18 [V], the motor 14 is forcibly stopped at that point in the same manner as described above. Thus, when it is desired to move the electric vehicle 16 even when the remaining capacity W is low, it is possible to use up the remaining capacity W of the battery 12 to the limit while minimizing damage to the battery 12. it can.

It should be noted that a clock function may be added to the main controller 30 so that the remaining running time T is added to the current time and displayed. For example, if the remaining running time T is one hour and thirty minutes and the current time is exactly at 3:00 pm, "until 4:30 pm" is displayed. In this case, convenience can be further improved.

[0024]

According to the display device of the first, second, third, fourth or fifth aspect, the remaining capacity of the battery is displayed as the remaining travel time when the vehicle is fully opened at the set maximum speed. The driver can clearly understand how much more he / she can actually drive by time. Therefore, it is extremely easy for the driver to plan and change the behavior, and the usability of the electric vehicle can be improved.

According to the display device of the second aspect, since the remaining travel time can be obtained by a very simple calculation formula, it is possible to facilitate programming and shorten the calculation processing time.

According to the display device of the third aspect, when the remaining travel time becomes equal to or less than a predetermined value, the remaining travel time is displayed. Thus, the driver can be clearly notified that the remaining running time has decreased.

According to the display device of the fourth aspect, when the remaining capacity becomes equal to or less than a predetermined value, the remaining running time is displayed as "0", so that the battery is charged early with the remaining capacity remaining to some extent. The driver can be encouraged to do so, so that damage due to overdischarge of the battery can be prevented.

According to the display device of the fifth aspect, the remaining capacity is displayed together with the remaining running time, so that the display of the remaining capacity allows the driver to be clearly notified of the charging time and the remaining running time. Even when is not displayed, by displaying the remaining capacity, it is possible to clearly inform the driver of the state of charge.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing a display device according to the present invention.

FIG. 2 is a configuration diagram showing an embodiment in which the display device according to the present invention is embodied more specifically.

FIG. 3 is a flowchart showing an operation of the main controller relating to the display device in the embodiment of FIG. 2;

FIG. 4 is a graph showing a relationship between speed and current consumption in the electric vehicle of the embodiment of FIG. 2;

FIG. 5 is a chart showing a display example on a display unit of the embodiment of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Display apparatus 12 Battery 14 Motor 16 Electric vehicle 18 Battery remaining capacity detecting means 20 Maximum speed setting means 22 Remaining running time calculating means 24 Display means Sm Maximum speed W Remaining capacity T Remaining running time

Claims (5)

[Claims] 1. A display device provided in an electric vehicle that runs by driving a motor with electric power of a battery, comprising: a remaining battery capacity detection unit that detects a remaining battery capacity; and setting a maximum speed of the electric vehicle. A remaining speed obtained by the remaining capacity detected by the battery remaining capacity detecting means when the vehicle is fully opened at the maximum speed set by the highest speed setting means. A display device for an electric vehicle, comprising: calculation means; and display means for displaying the remaining travel time calculated by the remaining travel time calculation means. 2. The remaining travel time calculation means, where W is the remaining capacity detected by the battery remaining capacity detection means, and I is the current consumption when the vehicle runs at full speed at the maximum speed set by the maximum speed setting means. The display device for an electric vehicle according to claim 1, wherein the remaining travel time T is calculated by an arithmetic expression T = W / I. 3. The display of the electric vehicle according to claim 1, wherein the display means displays the remaining travel time when the remaining travel time calculated by the remaining travel time calculation means becomes a certain value or less. apparatus. 4. The remaining travel time calculating means, when the remaining capacity detected by the battery remaining capacity detecting means has become equal to or less than a predetermined value, the remaining travel time calculated by the remaining travel time calculating means is set to “0”. The display device for an electric vehicle according to claim 1 or 2, wherein the remaining travel time is calculated so as to be "." 5. The display unit displays the remaining battery charge detected by the remaining battery charge detection unit together with the remaining travel time calculated by the remaining travel time calculation unit.
5. The display device for an electric vehicle according to 2, 3, or 4.