Display device of electric vehicle

Abstract

To provide a display device of an electric vehicle which can suppress giving a user a sense of discomfort in power display of a drive motor.SOLUTION: A display device of an electric vehicle comprises a drive motor 2 which generates driving force for traveling the electric vehicle 1, a power meter 3 which displays output of the drive motor 2 at percentage and a display control part 41 which displays the percentage of value dividing motor torque generated by the drive motor 2 by rating torque of the drive motor 2 to the power meter 3 in a stop region in which the vehicle speed of the electric vehicle 1 is at or below a prescribed vehicle speed and calculates value multiplying rotation frequency of the drive motor 2 by motor torque generated by the drive motor 2 as driving output when the vehicle speed of the electric vehicle 1 is out of the stop region and displays the percentage of the value dividing the driving output by the rating output of the drive motor 2 to the power meter 3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a display device for an electric vehicle. [Background technology]

[0002] Patent Document 1 describes that the calculated driving power is displayed on a driving power gauge.

[0003] As such, electric vehicles are equipped with a power meter that displays the power of the drive motor. A power meter generally displays the output of a drive motor as a percentage. Drive output [kW] is calculated by multiplying the motor torque by the number of revolutions. The percentage displayed by the power meter is the drive output divided by the rated output. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-114002 Summary of the Invention [Problem to be solved by the invention]

[0005] Since the driving output is the product of the motor torque and the rotation speed, when the driving force is balanced with the downward slope on an uphill road or when the vehicle is stopped with both the brake and accelerator pedals pressed, the driving output will be 0 [kW] and the percentage displayed on the power meter will be 0 [%].

[0006] However, in reality, the motor torque is being output and electric power is being used, which poses a problem that the display of the drive motor power can give the vehicle user a sense of incongruity.

[0007] SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a display device for an electric vehicle that can suppress the sense of discomfort felt by the user when displaying the power of a drive motor. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides a display device for an electric vehicle that runs using driving force generated by a drive motor and is equipped with a power meter that displays the output of the drive motor as a percentage, and when the vehicle speed of the electric vehicle is in a stopping area where it is below a predetermined vehicle speed, the display control unit causes the power meter to display the percentage of the value obtained by dividing the motor torque generated by the drive motor by the rated torque of the drive motor, and when the vehicle speed of the electric vehicle is outside the stopping area, the display control unit calculates the value obtained by multiplying the motor torque generated by the drive motor by the rotation speed of the drive motor as the drive output, and causes the power meter to display the percentage of the value obtained by dividing the drive output by the rated output of the drive motor. [Effects of the Invention]

[0009] In this way, according to the present invention, it is possible to prevent the user from feeling uncomfortable when the power of the drive motor is displayed. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a block diagram of an electric vehicle equipped with a display device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a flowchart showing the procedure of the power display control process of the display device according to one embodiment of the present invention. [Figure 3] FIG. 3 is a flowchart showing the procedure of the output limit control process of an electric vehicle equipped with a display device according to one embodiment of the present invention. [Figure 4] FIG. 4 is a flowchart showing a procedure of a power display control process of a display device according to another aspect of an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] A display device for an electric vehicle according to one embodiment of the present invention is a display device for an electric vehicle that runs using the driving force generated by a drive motor and is equipped with a power meter that displays the output of the drive motor as a percentage, and is configured to have a display control unit that, when the vehicle speed of the electric vehicle is in a stopping area where it is below a predetermined vehicle speed, causes the power meter to display the percentage of the value obtained by dividing the motor torque generated by the drive motor by the rated torque of the drive motor, and when the vehicle speed of the electric vehicle is outside the stopping area, calculates the value obtained by multiplying the motor torque generated by the drive motor by the rotation speed of the drive motor as the driving output, and causes the power meter to display the percentage of the value obtained by dividing the driving output by the rated output of the drive motor.

[0012] As a result, the display device for an electric vehicle according to one embodiment of the present invention can prevent the user from feeling uncomfortable when displaying the power of the drive motor. [Example]

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A display device for an electric vehicle according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

[0014] In FIG. 1, an electric vehicle 1 equipped with a display device according to one embodiment of the present invention includes a drive motor 2, a power meter 3, and a control device 4.

[0015] The drive motor 2 is provided to be linked to drive wheels (not shown) via power transmission members such as gear mechanisms. The drive motor 2 functions as an electric motor that rotates when supplied with power from a battery (not shown) or the like, thereby rotating the drive wheels, and also functions as a generator that converts the rotational force of the drive wheels into electric power.

[0016] The power meter 3 displays the output of the drive motor 2 as a percentage. The power meter 3 is composed of, for example, a monitor device, a lamp, a meter, etc., and is disposed on the instrument panel of the electric vehicle 1, etc.

[0017] The control device 4 is composed of a computer unit equipped with a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), flash memory for storing backup data, etc., input ports, and output ports.

[0018] The ROM of this computer unit stores a program for causing the computer unit to function as the control device 4, along with various constants and maps.

[0019] That is, the CPU executes the program stored in the ROM using the RAM as a work area, and this computer unit functions as the control device 4 in this embodiment.

[0020] To the input port of the control device 4, various sensors such as a motor rotation speed sensor 5, a vehicle speed sensor 6, a motor torque sensor 7, etc. are connected.

[0021] The motor rotation speed sensor 5 detects the rotation speed of the rotary shaft of the drive motor 2. The vehicle speed sensor 6 detects the speed of the electric vehicle 1. The motor torque sensor 7 detects the torque generated by the drive motor 2.

[0022] On the other hand, the output port of the control device 4 is connected to various control targets such as the drive motor 2 and the power meter 3 described above.

[0023] The control device 4 includes a display control unit 41 that controls the display of the power meter 3 , and a drive control unit 42 that controls the driving of the drive motor 2 .

[0024] The drive control unit 42 limits the output of the drive motor 2 by torque when the vehicle speed of the electric vehicle 1 is in a torque limit region below a predetermined torque limit vehicle speed. Because the torque that can be output is determined by hardware constraints of the battery and drive motor 2, the output is limited by torque rather than the output of the drive motor 2 in the low vehicle speed range.

[0025] In a stopping region where the vehicle speed of the electric vehicle 1 is equal to or lower than a predetermined vehicle speed, the display control unit 41 causes the power meter 3 to display a percentage of the value obtained by dividing the motor torque generated by the drive motor 2 by the rated torque of the drive motor 2. The display control unit 41 may set the torque limited region as the stopping region.

[0026] When the vehicle speed of the electric vehicle 1 is outside the stopping range, the display control unit 41 calculates the driving output by multiplying the motor torque generated by the drive motor 2 by the rotation speed of the drive motor 2, and causes the power meter 3 to display the percentage of the value obtained by dividing the driving output by the rated output of the drive motor 2.

[0027] If the percentage value obtained by dividing the motor torque by the rated torque of the drive motor 2 is displayed, the motor torque will be reduced when the vehicle is traveling at high speeds, and the power display value will be small even when the accelerator pedal is pressed, which will not match the user's accelerator work and may cause a sense of discomfort.

[0028] Therefore, when the vehicle is not in the stopping area, the power meter 3 displays the percentage of the value obtained by dividing the drive output by the rated output of the drive motor 2.

[0029] The display control unit 41 causes the power meter 3 to display 0% when the motor torque generated by the drive motor 2 is equal to or less than a predetermined value in a stopping region where the vehicle speed of the electric vehicle 1 is equal to or less than a predetermined vehicle speed.

[0030] The power display control process performed by the display control unit 41 of the display device according to this embodiment configured as described above will be described with reference to Fig. 2. The power display control process described below starts when the control device 4 starts operating, and is executed at preset time intervals.

[0031] In step S1, the display control unit 41 determines whether or not the vehicle speed of the electric vehicle 1 is in a stopping area where the vehicle speed is equal to or less than a predetermined vehicle speed.

[0032] If it is determined that the area is a stopping area, the display control unit 41 executes the process of step S2. If it is determined that the area is not a stopping area, the display control unit 41 executes the process of step S5.

[0033] In step S2, the display control unit 41 determines whether the motor torque is equal to or less than a predetermined value.

[0034] If it is determined that the motor torque is equal to or less than the predetermined value, the display control unit 41 executes the process of step S3. If it is determined that the motor torque is not equal to or less than the predetermined value, the display control unit 41 executes the process of step S4.

[0035] In step S3, the display control unit 41 displays 0[%] as the percentage to be displayed on the power meter 3. After executing the process of step S3, the display control unit 41 ends the power display control process.

[0036] In step S4, the display control unit 41 causes the power meter 3 to display a percentage obtained by dividing the motor torque generated by the drive motor 2 by the rated torque of the drive motor 2. After executing the process of step S4, the display control unit 41 ends the power display control process.

[0037] In step S5, the display control unit 41 causes the power meter 3 to display a percentage obtained by multiplying the motor torque generated by the drive motor 2 by the rotation speed of the drive motor 2 and dividing the result by the rated output of the drive motor 2. After executing the process of step S5, the display control unit 41 ends the power display control process.

[0038] The output limit control process performed by the drive control unit 42 of the electric vehicle 1 equipped with the display device according to this embodiment will be described with reference to Fig. 3. The output limit control process described below starts when the control device 4 starts operating, and is executed at preset time intervals.

[0039] In step S11, the drive control unit 42 determines whether the vehicle speed of the electric vehicle 1 is in a stopping region where the vehicle speed is equal to or less than a predetermined vehicle speed.

[0040] If it is determined that the area is a stopping area, the drive control unit 42 executes the process of step S12. If it is determined that the area is not a stopping area, the drive control unit 42 executes the process of step S13.

[0041] In step S12, the drive control section 42 limits the output of the drive motor 2 by the torque [Nm]. After executing the process of step S12, the drive control section 42 ends the output limit control process.

[0042] In step S13, the drive control section 42 limits the output of the drive motor 2 according to the output [kW]. After executing the process of step S13, the drive control section 42 ends the output limit control process.

[0043] In this way, in this embodiment, when the electric vehicle 1 is in a stopped region where the vehicle speed is below a predetermined vehicle speed, the power meter 3 displays the percentage of the motor torque generated by the drive motor 2 divided by the rated torque of the drive motor 2, thereby preventing the user from feeling uncomfortable when viewing the power display of the drive motor 2.

[0044] In addition, outside the stopping area, the drive output is calculated by multiplying the motor torque generated by the drive motor 2 by the rotation speed of the drive motor 2, and the percentage of the drive output divided by the rated output of the drive motor 2 is displayed on the power meter 3, so that the power display of the drive motor 2 does not cause any discomfort to the user.

[0045] In addition, if the motor torque is below a predetermined value in the stopped area, the power meter 3 displays 0%, so when torque is output to eliminate gear backlash, the user will not mistake the torque output while the vehicle is stopped for a malfunction and become anxious.

[0046] Furthermore, since the torque-limited region is set as the stopping region, the fluctuation of the displayed percentage in the torque-limited region can be made to coincide with accelerator work.

[0047] In another aspect of this embodiment, the display control unit 41 in FIG. 1 calculates the output base percentage as the percentage of the value obtained by dividing the drive output, which is the product of the motor torque generated by the drive motor 2 and the rotation speed of the drive motor 2, by the rated output of the drive motor 2, and calculates the percentage of the value obtained by dividing the motor torque generated by the drive motor 2 by the rated torque of the drive motor 2 as the torque base percentage, and displays the larger of the output base percentage and the torque base percentage on the power meter 3.

[0048] The display control unit 41 may be configured to filter the larger of the power base percentage and the torque base percentage and display the filtered value on the power meter 3. This filter is a filter that suppresses sudden changes in the value and smooths out changes in the value.

[0049] The power display control process performed by the display control unit 41 of the display device according to another aspect of the present embodiment configured as described above will be described with reference to Fig. 4. The power display control process described below starts when the control device 4 starts operating, and is executed at preset time intervals.

[0050] In step S21, the display control unit 41 determines whether or not the vehicle speed of the electric vehicle 1 is in a stopping region where the vehicle speed is equal to or less than a predetermined vehicle speed and the motor torque is equal to or less than a predetermined value.

[0051] If it is determined that the vehicle is in a stopping area and the motor torque is equal to or less than the predetermined value, the display control unit 41 executes the process of step S28. If it is determined that the vehicle is in a stopping area and the motor torque is not equal to or less than the predetermined value, the display control unit 41 executes the process of step S22.

[0052] In step S22, the display control unit 41 calculates, as an output base percentage, the percentage of the value obtained by dividing the drive output, which is the product of the motor torque generated by the drive motor 2 and the rotation speed of the drive motor 2, by the rated output of the drive motor 2. After executing the process of step S22, the display control unit 41 executes the process of step S23.

[0053] In step S23, the display control unit 41 calculates, as a torque base percentage, the percentage of the value obtained by dividing the motor torque generated by the drive motor 2 by the rated torque of the drive motor 2. After executing the process of step S23, the display control unit 41 executes the process of step S24.

[0054] In step S24, the display control unit 41 determines whether the output base percentage is equal to or greater than the torque base percentage.

[0055] If it is determined that the output base percentage is equal to or greater than the torque base percentage, the display control unit 41 executes the process of step S25. If it is determined that the output base percentage is not equal to or greater than the torque base percentage, the display control unit 41 executes the process of step S26.

[0056] In step S25, the display control unit 41 sets the output base percentage as the display percentage. After executing the process of step S25, the display control unit 41 executes the process of step S27.

[0057] In step S26, the display control unit 41 sets the torque base percentage as the display percentage. After executing the process of step S26, the display control unit 41 executes the process of step S27.

[0058] In step S27, the display control unit 41 causes the filtered value of the display percentage to be displayed on the power meter 3. After executing the process of step S27, the display control unit 41 ends the power display control process.

[0059] In step S28, the display control unit 41 displays 0[%] as the percentage to be displayed on the power meter 3. After executing the process of step S28, the display control unit 41 ends the power display control process.

[0060] In this way, in this embodiment, the larger of the output base percentage and the torque base percentage is displayed on the power meter 3. Therefore, in the low vehicle speed range where the rotation speed of the drive motor 2 is low, the output base percentage value becomes smaller and the torque base percentage value is displayed, thereby making it possible to prevent the user from feeling uncomfortable when the power of the drive motor 2 is displayed.

[0061] In addition, in the high vehicle speed range, the motor torque is reduced, the torque base percentage value becomes smaller, and the output base percentage value is displayed, which makes it possible to prevent the user from feeling uncomfortable when displaying the power of the drive motor 2.

[0062] Furthermore, the larger of the output base percentage and the torque base percentage is filtered and displayed on the power meter 3, so that sudden changes in the displayed percentage can be suppressed.

[0063] In this embodiment, an example has been described in which the control device 4 makes various determinations and calculations based on information from various sensors, but the present invention is not limited to this. The electric vehicle 1 may be provided with a communication unit capable of communicating with an external device such as an external server, and various determinations and calculations may be made by the external device based on detection information from various sensors transmitted from the communication unit. The determination results and calculation results may be received by the communication unit, and various controls may be performed using the received determination results and calculation results.

[0064] While an embodiment of the present invention has been disclosed, it will be apparent to one skilled in the art that modifications may be made thereto without departing from the scope of the present invention, and it is intended that all such modifications and equivalents be included in the following claims. [Explanation of symbols]

[0065] 1 Electric vehicles 2 drive motor 3 Power Meter 4. Control device 5 Motor rotation speed sensor 6 Vehicle speed sensor 7 Motor torque sensor 41 Display control unit 42 Drive control unit

Claims

1. A display device for an electric vehicle that runs using driving force generated by a drive motor and is equipped with a power meter that displays the output of the drive motor as a percentage, A display device for an electric vehicle comprising: a display control unit that, when the vehicle speed of the electric vehicle is in a stopping region where it is equal to or lower than a predetermined vehicle speed, causes the power meter to display a percentage of the value obtained by dividing the motor torque generated by the drive motor by the rated torque of the drive motor; and, when the vehicle speed of the electric vehicle is outside the stopping region, causes the display control unit to calculate a drive output by multiplying the motor torque generated by the drive motor by the rotation speed of the drive motor, and to display on the power meter a percentage of the value obtained by dividing the drive output by the rated output of the drive motor.

2. A display device for an electric vehicle that runs using driving force generated by a drive motor and is equipped with a power meter that displays the output of the drive motor as a percentage, a display device for an electric vehicle comprising: a display control unit that calculates an output base percentage as a percentage of a value obtained by multiplying the motor torque generated by the drive motor and the rotation speed of the drive motor, and dividing the result by the rated output of the drive motor; a display control unit that calculates a torque base percentage as a percentage of a value obtained by dividing the motor torque generated by the drive motor by the rated torque of the drive motor; and a display control unit that causes the power meter to display the larger of the output base percentage and the torque base percentage.

3. The display device for an electric vehicle according to claim 2 , wherein the display control unit causes the power meter to display a value obtained by filtering the larger value of the power base percentage and the torque base percentage.

4. 4. The display device for an electric vehicle according to claim 1, wherein the display control unit causes the power meter to display 0% when the motor torque generated by the drive motor is equal to or less than a predetermined value in a stopping region where the vehicle speed of the electric vehicle is equal to or less than a predetermined vehicle speed.

5. the electric vehicle includes a drive control unit that limits the output of the drive motor by torque when the vehicle speed of the electric vehicle is in a torque limit region equal to or lower than a predetermined torque limit vehicle speed; The display device for an electric vehicle according to claim 1 , wherein the display control unit sets the torque limited region as the stopping region.

Images