JP4289719B2 - Electric car - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an improvement of an electric vehicle that travels using a motor as a drive source.
[0002]
[Prior art]
Conventionally, this type of electric vehicle is limited to a maximum speed of 6 km / h as a pedestrian when traveling on a road, such as an electric wheelchair or an electric tricycle. During traveling, the motor was controlled so that the traveling speed was fed back and the speed instructed within this speed range.
[0003]
When driving this electric car on a downhill, if the inclination angle becomes steep, it becomes longer than the stopping distance on a flat road, or it becomes unstable in traveling such as it becomes difficult to bend stably at the same traveling speed. It was. In particular, when driving at the maximum speed (6 km / h), which is the most demanding condition, even if there is an obstacle, the stopping distance is longer than that on a flat road, so it will not be able to stop and will collide or fall when it turns. There was a fear of doing it.
[0004]
In consideration of this point, in Japanese Patent Laid-Open No. 4-138001, it is determined from the amount of generated current of the motor whether or not it is safe to drive even if the downhill inclination angle travels at the maximum speed. When a predetermined value set in advance is exceeded, it is judged dangerous and the maximum speed is limited.
[0005]
However, since the predetermined value of the amount of generated current described above was determined to be a predetermined value based on the case of a person with a reference weight, the speed of the person with a heavier weight than the reference weight is lower than the reference downhill. In the case of a light person, the speed was not limited to a tight inclination angle from the standard downhill. For this reason, in the case of a heavy person, the time to an arrival point becomes long and stresses the operator, and in the case of a light person, there is a high risk of falling.
[0006]
In addition, the tilt angle that becomes dangerous while traveling downhill varies depending on individual differences, for example, the steering ability, but these are not considered in the conventional electric vehicle, and are not easy to use.
[0007]
[Problems to be solved by the invention]
It is an object of the present invention to provide an electric vehicle that can travel safely and without causing time loss in a state suitable for the weight and operating ability of a driver.
[0008]
[Means for Solving the Problems]
A first means for solving the above problems includes a motor as a driving source, a speed instruction means for instructing a traveling speed, a speed detecting means for detecting a traveling speed, and an output of the speed instruction means and a speed detection. A traveling speed control means for controlling with a drive signal and a braking signal so as to obtain an instruction speed based on the output of the means, a power generation amount detection circuit for detecting a power generation amount of the motor at the time of braking, and a reference according to the traveling speed A maximum speed limiting means for limiting a maximum speed when the power generation amount detected by the power generation amount detection circuit is equal to or greater than a reference power generation amount, and a setting means for correcting the reference power generation amount Is provided.
[0009]
As a result, when it is heavier than the reference weight, it is larger than the standard power generation amount, when it is light, it is small, and when the pilot's maneuverability is high, it is larger and lower than the standard power generation amount. In some cases, the reference power generation amount can be corrected small. Thereby, even when a person other than the reference weight uses, the inclination angle of the downhill that restricts the maximum speed can always be constant. In addition, since the downhill inclination angle that limits the maximum speed can be changed and set according to the conditions such as the maneuvering ability of the person who uses it, it prevents time loss by slowing down and reduces the stress of the driver Can be reduced.
[0010]
In the above-described configuration, a loading weight detection unit that detects a loading weight is provided, and the setting unit corrects the reference power generation amount based on an output of the loading weight detection unit.
[0011]
As a result, even if there is a difference between the tilt angle converted from the power generation amount and the actual tilt angle, it is automatically corrected by the output from the load weight detecting means, and the downhill tilt angle that limits the maximum speed is made constant. can do.
[0012]
Further, an input connected to the running speed control means is provided, the setting means corrects the power generation by the standards based on the input values of the input section.
[0015]
Embodiment
1 to 9 show an embodiment of the present invention by taking an electric tricycle as an example, and will be described below based on these drawings.
[0016]
An electric tricycle 1 includes a front wheel 2 and a pair of rear wheels 3 as shown in FIG. 1. The front wheel 2, a handle and 4 are connected by a steering shaft 5. 2 is steered to control the traveling direction.
[0017]
Reference numeral 6 denotes an operation unit provided on the handle 4, a motor (not shown) for driving the rear wheel 3, an accelerator lever 8 for instructing the rotational speed (traveling speed) of the motor, and a maximum speed that can be instructed by the accelerator lever 8. Is operated by a maximum speed changeover switch (not shown) for switching between, forward / reverse changeover switch (not shown) for switching forward / backward movement of the electric vehicle 1, and a detachable key (not shown) to control power supply to the motor. It has a power switch (not shown) and the like.
[0018]
Reference numeral 10 denotes a cover body that covers the front of the steering shaft 5. A headlamp 11 is attached to the front of the steering shaft 5.
[0019]
Reference numeral 13 denotes a chair on which a driver sits, and a motor, a battery (not shown) serving as a power source for the motor, a drive circuit (not shown) for controlling the motor, and the like are provided in a cover 14 disposed below the chair. .
[0020]
Next, the drive circuit will be described with reference to FIG.
[0021]
Reference numeral 15 denotes a speed instruction circuit as speed instruction means, and the resistance value of the variable resistor 16 is changed by the operation of the accelerator lever 8, that is, by pushing or lowering the accelerator lever 8. At this time, a speed instruction signal for instructing the traveling speed according to the resistance value of the variable resistor 16 is output to the control circuit 17.
[0022]
Reference numeral 18 denotes a rotation speed detection circuit as speed detection means, which detects the rotation speed of the motor 7 and calculates the actual traveling speed based on this rotation speed. This travel speed is output to the control circuit 17 as a travel speed signal. The control circuit 17 outputs a drive signal and a braking signal to the motor drive circuit 19 based on the travel speed signal and the speed instruction signal. These control circuit 17 and motor drive circuit 19 constitute a travel control means. The control signal described above is a PWM signal for turning on the switching element 19a for applying the dynamic braking with the motor 7 closed circuit. The drive signal is a PWM signal that turns on the switching element 19b for energizing the motor 7.
[0023]
The motor drive circuit 19 drives the motor 7 when the drive signal is output, and when the brake signal is output, the motor 7 performs power braking by the motor 7 so as to travel at the indicated speed. At this time, the amount of current generated by the motor 7 is detected by a power generation amount detection circuit, that is, a current detection circuit 20, and automatically decelerates when the amount of current generated by the motor 7 exceeds a reference amount of power generation current as will be described later. Control is performed.
[0024]
Here, in the present embodiment, the amount of generated current at the time of power generation braking is detected by the current detection circuit 20, but the present invention is not limited to this, and the braking output from the motor drive circuit 19 is not particularly limited. The PWM value of the signal may be determined as the amount of generated current.
[0025]
Reference numeral 21 denotes a forward / reverse switching switch for switching forward / reverse rotation of the motor 7 via the control circuit 17. When the forward contact 21 a side is closed, the motor 7 is rotated forward, and when the reverse contact 21 b side is closed, the motor 7 is reversed.
[0026]
An electromagnetic brake circuit 22 controls an electromagnetic brake (not shown), and stops energization to the electromagnetic brake when the power switch 23 is opened to stop the vehicle. At this time, the electromagnetic brake works to prevent the rear wheel 3 from rotating.
[0027]
Reference numeral 24 denotes a step-down circuit that steps down the voltage supplied from the battery 25 to a predetermined voltage, and supplies the power supply voltage to the control circuit 17 by closing the contact of the power switch 23.
[0028]
A remaining amount display circuit 26 displays a battery voltage value and controls lighting of a plurality of LEDs (not shown) according to the voltage of the battery 25.
[0029]
Reference numeral 27 denotes a maximum speed changeover switch provided on the operation unit 6, a low speed contact 27a for setting the maximum speed to a low speed (2 km / h in this embodiment), and a maximum speed to a medium speed (4 km / h in this embodiment). ) And a high-speed contact 27c for setting the maximum speed to a high speed (6 km / h in this embodiment). A maximum speed setting signal is output to the control circuit 17 in accordance with the operation of the maximum speed changeover switch 27. Further, the control circuit 17 is made to travel at a speed corresponding to the operation of the maximum speed changeover switch 27 and the operation amount of the accelerator lever 8.
[0030]
Reference numeral 28 denotes weight detection means for detecting the weight of the operator, and is provided below the chair 13 as shown in FIG. The weight detecting means 28 uses a pressure sensitive rubber 29 in the present embodiment, and outputs a weight signal to the control circuit 17 in accordance with a resistance change of the pressure sensitive rubber 29. The control circuit 17 automatically calculates a weight value based on the weight signal.
[0031]
Next, the operation will be described.
[0032]
When the power switch 23 is closed and the accelerator lever 8 is pushed down, a speed instruction signal is output from the speed instruction circuit 15 to the control circuit 17, and the control circuit 17 drives the motor 7 via the motor drive circuit 19. At this time, the electric vehicle 1 moves forward when the forward / reverse selector switch 21 is closed to the forward contact 21a side, and retreats when it is closed to the reverse contact 21b side.
[0033]
When the motor 7 of the electric tricycle 1 starts to rotate, the rotational speed detection circuit 18 detects the rotational speed of the motor 7 and outputs a traveling speed signal to the control circuit 17. The control circuit 17 outputs a drive signal and a braking signal to the motor drive circuit 19 based on the travel speed signal and the speed instruction signal. That is, when the traveling speed becomes lower than the speed instruction speed, the driving signal increases, and the motor driving circuit 19 outputs the driving signal to drive the motor 7. On the other hand, when the traveling speed becomes faster, the braking signal increases. This is output to the motor drive circuit 19 and is generated and braked by the motor 7. In this way, the traveling speed of the electric vehicle 1 is made to travel at the indicated speed.
[0034]
When the electric tricycle 1 travels downhill, a large braking signal is output to the motor drive circuit 19, and a generated current is generated in the motor 7. When this generated current reaches a reference generated current amount, it is determined that the angle of inclination is dangerous, and automatic deceleration control described later is performed to limit the maximum speed. At this time, there is a difference between the actual inclination angle at which automatic deceleration control is performed and the reference set inclination angle depending on the weight of the driver, but the difference is corrected by a correction value described later.
[0035]
Here, the reference set inclination angle is the amount of power generation current generated at an inclination angle at which traveling at the maximum speed (maximum speed 6 Km / h at high speed in the embodiment of the present invention) becomes dangerous is the traveling speed. Is set based on a person with a reference weight (70 kg in this case). Similarly, a predetermined value is set in advance according to each traveling speed.
[0036]
Next, a reference generated current amount and a correction value for correcting the reference generated current amount will be described with reference to FIGS.
[0037]
FIG. 3 shows the weight value A of the driver on the horizontal axis, and a correction value B (described later) for correcting the reference generated current amount on the vertical axis, and the correction value B is determined for each weight assuming that the reference weight is 70 kg. For example, when the weight value A is 80 kg, the correction value B is 1.05.
[0038]
Next, a description will be given based on the flowchart.
[0039]
In step S1, it is determined whether the power switch 23 is closed. If it is closed, the process proceeds to step S2.
[0040]
In step S2, the weight value A of the driver is calculated based on the output signal of the weight detection means 28. In step S3, the correction value B for the weight value A (for example, about 1.05 for a person of 80 kg). Is calculated from the graph shown in FIG.
[0041]
In step S4, a reference generated current amount D (a generated current amount serving as a reference in the case of a person with a reference weight of 70 kg) is calculated according to the traveling speed.
[0042]
In step S5, the correction is performed by multiplying the reference generated current amount D by the correction value B, and this value is calculated as a corrected reference generated current amount D1.
[0043]
In step S6, it is determined whether or not the current generated current amount during traveling exceeds the corrected reference generated current amount D1, and if so, the process proceeds to downhill automatic deceleration control E. On the other hand, if not exceeding, normal traveling is performed in step S7.
[0044]
Next, the downhill automatic deceleration control E, that is, the automatic deceleration control of the above-described flowchart will be described.
[0045]
In step S8, it is determined whether or not this state continues for a predetermined time or longer (in this embodiment, 0.5 second or longer).
[0046]
If it continues for a certain time or more, it is determined in step S9 whether or not the maximum speed changeover switch 27 is connected to the high speed contact 27c. If it is connected to the high-speed contact 27c, it is determined that the tilt angle is dangerous when traveling at the maximum speed, and in step S10, the maximum speed changeover switch 27 is connected to the high-speed contact 27c. Set the maximum speed to medium speed. As a result, the traveling speed is limited so that the vehicle can travel safely.
[0047]
If NO is determined in step S8 to step S9, it is determined that the vehicle is not a dangerous downhill, and the normal traveling in step S12 is performed, and the process returns to step S4.
[0048]
With the above configuration, even if the inclination angle of the downhill that limits the maximum speed is different from the value converted from the reference power generation current amount D and the actual inclination angle, the output from the weight detection means 28 Since the correction can be made automatically, it can be corrected that the automatic deceleration control works on a downhill having a smaller inclination angle or the automatic deceleration control works on a downhill having a larger inclination angle than the dangerous inclination angle. As a result, there is a time loss due to the automatic deceleration control working on a downhill that is smaller than the dangerous tilt angle, or the automatic deceleration control does not work even if the dangerous tilt angle is reached, and there is a risk of falling and the stopping distance is extended. It is possible to prevent the possibility of collision with an obstacle from increasing, and the vehicle can travel safely and without feeling stress.
[0049]
In addition, since the correction value is automatically determined, the operation for correction is unnecessary and the usability is improved.
[0050]
In the above embodiment, automatic deceleration control is performed in which the high speed is set to a medium speed when traveling at a high speed. However, an automatic deceleration control in which the medium speed is set to a low speed may be performed. Automatic deceleration control may be performed in stages, such as performing automatic deceleration control that lowers from medium speed to low speed later.
[0051]
Further, automatic deceleration control for decelerating from high speed to an arbitrary speed may be performed instead of automatic deceleration control for changing the maximum speed from high speed to medium speed.
[0052]
In addition, instead of providing the weight detection means 28 to measure the weight of the driver, a load weight detection means for detecting the load weight is provided in the vicinity of the damper on the rear wheel side, and the output from the load weight detection means. The above correction value may be calculated based on this.
[0053]
Next, another embodiment will be described with reference to FIGS. In the embodiment shown in FIG. 2, the weight value A is set based on the output from the weight detecting means 28. Instead of determining the correction value B based on the weight value A, a key input is made in this embodiment. The correction value B can be determined from the body weight value, and the correction value B can be further corrected by inputting the mode value by key input.
[0054]
A key input unit 30 connected to the control circuit 17 includes a numeric keypad 31, a weight display unit 32 that displays a weight value, and a mode display unit 33 that displays a mode value. A value can be entered.
[0055]
The numeric keypad 31 includes a key 31a from 0 to 9, an asterisk key 31b, and a sharp key 31c. The sharp key 31c switches between the input of the weight value and the input of the mode value.
[0056]
The body weight value is input as a positive number (60 kg is input here), and the mode value is input as 1, 2, or 3. The input value is obtained by pressing the asterisk key 31b. Is output to the control circuit 17.
[0057]
FIG. 7 shows the correlation between the weight value A and the correction value B with respect to each value of the mode value, with the weight value A on the horizontal axis and the correction value B on the vertical axis. In this case, the solid line indicates the mode 2 and the alternate long and short dash line indicates the mode 3. While these modes are based on mode 2 (same as the above-mentioned embodiment and the same as the solid line in FIG. 3), at the same weight value, mode 1 corrects so that correction value B is increased by 0.03, In mode 3, the correction value B is corrected so as to become 0.03 smaller.
[0058]
Next, calculation of the correction value B will be described.
[0059]
When the mode value 2 is input, the correction value B is calculated based on the solid line in FIG. When the input of the weight value A is 60 kg, the correction value B is 0.95.
[0060]
When mode 3 is input, the correction value B is calculated based on the one-dot chain line in FIG. When the same weight value 60 kg as in the mode 2 is input, the correction value B is set to 0.92, which is 0.03 smaller than that in the mode 2. As a result, the reference amount of generated current is corrected to a value that is 3% smaller, and the tilt angle at which automatic deceleration control is performed becomes smaller than in mode 2. Therefore, automatic deceleration control is performed even when the angle of inclination is smaller than that of the standard mode 2, and it is possible to run with a margin, so I think that elderly people and maneuverability are low. It becomes possible to run suitable for the person who is.
[0061]
On the other hand, when mode 1 is input, the correction value B is calculated based on the broken line in FIG. When the same weight value 60 kg as in modes 2 and 3 is input, the correction value B is set to 0.98, which is 0.03 larger than that in mode 2. As a result, the reference generated current amount is corrected to a value that is 3% larger, and the tilt angle at which automatic deceleration control is performed becomes larger than in mode 2. As a result, even if the inclination angle that is automatically decelerated in mode 2 is reached, the automatic decelerating control is not performed, and the destination can be reached earlier instead of the risk of falling or colliding. This is suitable for those who have high ability to avoid danger, such as young people and those who are good at maneuvering.
[0062]
Next, a method of correcting the correction value B by inputting the weight input value A heavier or lighter than the actual weight will be described. In the following description, it is assumed that the reference mode 2 is input.
[0063]
When 60 kg is input as the weight value A with respect to the weight of 70 kg of the pilot, the correction value is 0.95, which is 0.05 smaller. In this case, the reference generated current amount is smaller than the value based on the weight of the operator, and the inclination angle at which the automatic deceleration control works is small. As a result, as in the case of mode 3, automatic deceleration control is performed even on a downhill that is smaller than a dangerous inclination angle, and it is possible to drive with a margin, so that it is possible to control elderly people and maneuvering ability. It is suitable for people who think that is low.
[0064]
On the other hand, when the operator's weight is 70 kg and 80 kg is input as the weight value A, the correction value is 1.05, which is 0.05 larger. In this case, the reference generated current amount is larger than the value based on the weight of the operator, and the tilt angle at which the automatic deceleration control works is increased. As a result, the automatic deceleration control is not performed even when the dangerous tilt angle is reached as in the case of the mode 1, so that the destination can be reached earlier instead of the risk of falling or colliding. The driving is suitable for young people and those with good ability to avoid danger, such as those who are good at maneuvering.
[0065]
The above correction value is 0.91 when 50 kg, which is smaller than 60 kg, is input to the weight value A, which is 0.04 smaller than that when 60 kg is input, and the weight value A is 80 kg. When an even larger 90 kg is input, the correction value is 1.09, which is 0.04 larger than when 80 kg is input. Accordingly, the correction value B can be appropriately changed by changing the weight value A input using the weight of the pilot as a guideline, so that it can be made more suitable for the individual characteristics of the pilot who uses the weight of the pilot as a guideline.
[0066]
In another embodiment shown in FIG. 7, when inputting the weight value, the weight value detected from the weight detecting means 28 may be displayed, and this value may be changed by switching the mode value. In this way, if the actual weight of the pilot is entered, the reference generated current can be set automatically by changing the mode, so the setting operation is not complicated. It will be good.
[0067]
Further, instead of inputting the weight value and correcting the reference generated current amount, a value correlated with the weight value may be input to correct the reference generated current amount.
[0068]
【The invention's effect】
According to the first aspect of the present invention, the setting speed can be corrected even if a difference occurs between the inclination angle for limiting the maximum speed and the value converted from the power generation amount and the actual inclination angle, so the maximum speed is limited. With the inclination angle always constant, the vehicle can travel safely without risk of time loss or falling. In addition, since the downhill inclination angle that limits the maximum speed can be changed and set according to conditions such as age and maneuverability, the vehicle can travel comfortably in a state suitable for the user.
[0069]
According to claim 2 of the present invention, even if there is a difference between the inclination angle converted from the power generation amount and the actual inclination angle, the output is automatically corrected by the output from the load weight detecting means, and the maximum speed is limited. Since the slope angle of the slope can be made constant, the vehicle can travel safely without causing danger such as time loss or falling, and the operation for correction is not required and the usability is improved.
[0070]
According to the third aspect of the present invention, since the reference power generation amount can be arbitrarily corrected by the input value, it can be easily corrected to a state suitable for the weight, age and operation ability of the operator.
[Brief description of the drawings]
FIG. 1 is an external view of an electric vehicle showing an embodiment of the present invention.
FIG. 2 is a block diagram of a control circuit of the electric vehicle.
FIG. 3 is a diagram showing the relationship between the correction value of the electric vehicle and the weight of the driver.
FIG. 4 is a flowchart for correcting a reference generated current amount of the electric vehicle.
FIG. 5 is a flowchart of downhill automatic deceleration control of the electric vehicle.
FIG. 6 is a plan view of a key input unit of an electric vehicle showing another embodiment.
FIG. 7 is a graph showing the relationship between the correction value and the weight value of the electric vehicle for each mode.
[Explanation of symbols]
7 motor 15 speed instruction circuit (speed instruction means)
18 Speed detection circuit (speed detection means)
20 Current detection circuit (Power generation detection circuit)
28 Weight detection means (loading weight detection means)
31 Key input part (input part)
A Weight value B Correction value D Reference generated current

Claims (3)

  A motor as a drive source, a speed instruction means for instructing a traveling speed, a speed detecting means for detecting a traveling speed, and the motor to be instructed based on an output of the speed instruction means and an output of the speed detecting means. A travel speed control means for controlling with a drive signal and a braking signal, a power generation amount detection circuit for detecting a power generation amount of the motor at the time of braking, a reference power generation amount according to the travel speed, and setting the power generation amount detection An electric vehicle comprising: a maximum speed limiting unit that limits a maximum speed when a power generation amount detected by a circuit is equal to or greater than a reference power generation amount; and a setting unit that corrects the reference power generation amount. The loaded weight detecting means for detecting a load weight provided, the setting means electric vehicle according to claim 1, wherein the correcting the power generation amount of the criteria based on the output of the load weight detecting means. Said input connected to the running speed control means is provided, the setting means electric vehicle according to claim 1, wherein the correcting the power generation amount of the criteria based on the input values of the input section.

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