JPH0386005A - Motor chair - Google Patents

Abstract

PURPOSE:To prevent collision against an obstacle by limiting the maximum speed to a predetermined value according to a signal fed from a sensor for detecting an object existing in the detection area in the running direction of a vehicle. CONSTITUTION:An object detecting sensor 19 is mounted in the front center of the steering shaft of a vehicle 1. The object detecting sensor 19 detects an object existing in the detection area thereof and produces a detection signal which is then transmitted to a drive control means for limiting the maximum speed to a predetermined level. If an object is detected when the vehicle is running at higher speed than the limit speed, the speed is controlled automatically and thereby the vehicle can be braked before it collides against the object or can steer clear of the object. By such arrangement, safety running can be carried out and collision against an obstacle such as a pedestrian can be prevented.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a power wheelchair.

[Prior Art] An electric wheelchair includes an operating means for setting and operating the forward and reverse traveling direction and speed of the vehicle body, a drive control means for controlling the running of the vehicle body operated by the operating means, and a drive M for the electric wheelchair.
It is composed of a driving means consisting of a motor that is heated by the # means and a braking device for applying braking, and uses a battery as a driving power source.

[Problem to be solved by the invention] By the way, wheelchairs are originally intended for people with physical disabilities and the elderly, and sufficient consideration has been given not only to the safety of the users themselves, but also to the risk of collisions with passersby. something is needed.

However, in the above-mentioned conventional example, avoidance of obstacles was performed by the user's operation, which resulted in a problem of low safety for not only the user but also passersby.

The present invention has been made in view of the above problems, and an object of the invention as claimed in claim 1 is to limit the maximum speed to a predetermined value when an object is detected within the detection area of the object detection sensor. To provide an electric wheelchair that enables safe driving and prevents accidents due to collisions with obstacles such as passersby.

An object of the invention set forth in claim 2 is to provide an electric wheelchair that is further improved in safety in the invention set forth in claim 1.

Furthermore, the invention as claimed in claim 3 is the invention as claimed in claim 1, in which the object detection area is changed according to the vehicle speed to ensure the detection of obstacles within a distance range according to the vehicle speed, thereby improving safety. The invention according to claim 4 is characterized in that it provides an electric wheelchair that can travel at high speeds, and when the vehicle body collides with an obstacle, the vehicle automatically stops traveling, thereby preventing accidents caused by collisions with obstacles. There is a power wheelchair available.

The invention set forth in claim 5 is to provide an electric wheelchair according to the invention set forth in claim 4, which can reliably detect a collision with an obstacle when turning or the like and automatically stop the wheelchair from traveling.

[Means for Solving the Problems] The invention according to claim 1 includes an object detection sensor that detects an object within a detection area with its detection direction facing the traveling direction of a vehicle body, and a detection signal from the object detection sensor that is inputted. and drive control means for limiting the maximum speed that can be produced to a predetermined value, and the invention according to claim 2 is such that the predetermined value is set to be smaller as the distance to the object detected by the object detection sensor is shorter. This is what I did. Further, the invention as set forth in claim 3 is configured to change the detection area of the object detection sensor in accordance with the traveling speed of the vehicle body.

The invention as set forth in claim 4 is provided with a collision sensor attached to the vehicle body to detect a collision with an object, and drive IIJ control means for stopping traveling when a detection signal from the collision sensor is input, and claim 5. In the described invention, the collision sensors are attached to the front end and both front side surfaces of the vehicle body.

[Operation] According to the invention described in claim 1, if there is an object in the detection area of the object detection sensor, the object detection sensor detects this, and the drive control means that receives the detection signal adjusts the maximum speed that can be produced. It can be limited to a predetermined value. Therefore, due to this restriction, if the object detection sensor detects an object while driving at a speed higher than a predetermined value, the speed will be automatically controlled and there will be enough time to apply braking before colliding with the object. This makes it easier to prevent a collision by giving the user more room to avoid the vehicle by operating the steering wheel, and it also allows the user to avoid causing a collision with an object by increasing the speed due to careless operation. be.

According to the invention described in claim 2, the closer the object detected by the object detection area is to the object, the lower the maximum speed is limited to a predetermined value, thereby increasing the traveling speed to a speed at which collision with the object can be easily avoided. - Enables safe travel of the layer.

Further, according to the invention as claimed in claim 3, by changing the detection area of the object detection area according to the vehicle speed, object detection can be performed in an optimal detection area suitable for the speed even when driving at low speed or high speed. This can be done inside the vehicle, allowing the vehicle to move safely before it collides with an object.

On the other hand, according to the invention set forth in claim 4, when the vehicle body collides with an object while traveling, the collision sensor detects this collision, and upon this detection, the drive control means stops the traveling, so that it is possible to safely prevent the vehicle from colliding with the object. Automatically stops to prevent accidents caused by collisions. In particular, according to the invention as set forth in claim 5, it is possible to reliably detect a collision between the front side of the vehicle body and an object that occurs when turning a corner, and it is also possible to prevent accidents caused by collisions when turning a corner.

[Example] The present invention will be explained below with reference to Examples.

The electric wheelchair of this embodiment has a three-wheeled configuration as shown in FIG. 1, and a speed reducer with a differential is installed in the vehicle body 1 below the seat 2 provided at the rear of the vehicle body 1, as shown in FIG. through rear wheel 4
The electric wheelchair is equipped with a drive section consisting of a motor 5 that drives the electric wheelchair, and an electromagnetic brake 6 that applies braking by sandwiching the axle of the rear wheels 4, and a battery BT that serves as a power source for driving the electric wheelchair.

At the front of the vehicle body l, there is a handle shaft connected to the front wheels 7, which changes the running direction of the front wheels 7 when rotated in the horizontal direction;
A handle part is provided which consists of a handle 9 fixed to the upper end of this handle shaft, and this handle part has an accelerator 8 for controlling the running speed in the forward and reverse directions, a key switch KS, and a key switch KS for controlling the maximum speed. , speed setting switches sw and -sw for switching to medium speed and low speed, on/off operation switch SW4 for light 11, alarm buzzer -1
an operation switch section 10 consisting of two on/off operation switches SW5; display lamps L1 to L for displaying the remaining capacity of the battery BT; and display lamps L4 to L for displaying the set speed and reverse movement. 3, the light 11 is attached to the front upper part of the handle shaft, and a collision sensor 14 is attached to the front wheel cover 3. Further, an object detection sensor 19 is attached to the center front part of the handle shaft.

The accelerator 8 is turned off at the neutral point as shown in Figure 4,
The forward speed can be adjusted by rotating clockwise in the figure where the vehicle is tilted forward, and the reverse speed can be adjusted by rotating counterclockwise in the diagram where the vehicle is tilted backwards.

The collision sensor 14 operates when an object collides to generate a collision detection signal, and in this embodiment, as shown in FIG. As shown in FIG. 6(a), a movable electrode 16a and a fixed electrode 16b are arranged side by side in the longitudinal direction of the housing 15 with a gap in between. The literature section 17a provided in the internal longitudinal direction is movable! ! 1
6a, the picture electrodes 16a and 16b are separated, but when they collide with an obstacle and an external force is applied to the external literature portion 17b in the direction of the arrow, as shown in FIG. , the housing 15 bends and the internal literature section 17a becomes the movable electrode 16a.
is pressed against its elasticity to bring the movable electrode 16a into contact with the fixed electrode 16b and turn it on, and this on-operation signal becomes a collision detection signal and the image electrode 16a,
It can be taken out from lead wires 18a and 18b connected to 16b, respectively. When the external force is removed, the housing 15 returns to its original state due to its elasticity, and the movable electrode 16a also returns to its original state.

The object detection sensor 19 detects objects by emitting signals such as ultrasonic waves, light, and radio waves. In the embodiment, as shown in FIG. The sensor circuit 20 is composed of a transducer 21 that receives waves, and a sensor circuit 20 that processes signals. 20, an amplifier circuit 20c that amplifies the received signal of the reflected wave received by the transducer 20, and an amplifier circuit 20c that amplifies the received signal of the reflected wave received by the transducer 20. It is composed of a detection signal generation circuit 20d that generates the detection signal, and a distance data generation circuit 20e that detects the distance to the object from the delivery signal and generates distance data. The detection distance is controlled by the input distance control input signal, and the width of the detection area is controlled by the gain control input signal input from the outside to the amplifier circuits 20b and 20C, so that the detection area can be varied.

Now, Figure 2 shows the overall circuit configuration of the electric wheelchair of the present invention, which is composed of a microcomputer, etc. *J1
1 circuit 25 constitutes the central part that controls the running of the electric wheelchair and monitors each part, and is an A/D conversion value of the output voltage from the variable resistor ■R that changes the voltage division ratio according to the operation of the accelerator 8. In addition to determining whether to move forward or backward, the operation amount and the operation of speed setting switches SW1 to SWs, the rotation detection signal from the tacho generator 24 that performs speed detection, the collision detection signal of the collision sensor 14, and the object detection sensor 19
A drive control function that generates a control signal for the brake drive circuit 23 that drives the electromagnetic brake 6 and controls the motor drive signal output to the motor drive circuit 22 according to the object detection signal and distance data from the controller, and the operation switch. In response to the input of the operation signal of SW, SW9, the light 11 blinks and the alarm buzzer is activated.
12, as well as functions for creating a gain control input signal and a distance control input signal for changing the detection area of the object detection sensor 19 according to the vehicle speed.

When all the users (passengers) turn on the key switch KS, the control circuit 25 operates using the battery BT as a power source to control and monitor each part.

Here, when the user pushes the accelerator 8 forward, the resistance value of the variable resistor VR linked to the accelerator 8 changes, and the divided voltage output from the slider end becomes A/D conversion N2.
6, the control circuit 25 detects from the voltage value that it has been operated in the forward direction and outputs a forward/reverse switching signal to the motor drive circuit 22, and also provides a control signal to the brake drive circuit 23. to unlock the electromagnetic brake 6.

Next, the control circuit 25 determines the operation amount of the accelerator 8 from the voltage that is the accelerator input, and outputs a PWM pulse with a duty corresponding to this operation amount. That is, in the embodiment, the motor is driven by PWM control, and the control circuit 25 creates pulses for this PWM control as a motor drive signal.

Now, the motor drive circuit 22 changes the operating mode from the stop mode to the running mode, and drives the motor 5 in a PWM manner based on the forward/reverse switching signal.

When the motor 5 rotates according to the PWM duty, the rotation speed is detected by the tacho generator 24 attached to the motor shaft, and the control circuit 25 calculates the vehicle speed based on the rotation detection signal from the tacho generator 24, and calculates the vehicle speed and the accelerator. and P based on the comparison result.
By increasing or decreasing the WM duty, the vehicle speed is controlled to correspond to the accelerator operation amount. This feedback ff11m allows the electric wheelchair of the present invention to travel at a constant speed even on uphill and downhill slopes.

The maximum vehicle speed at this time is the speed setting switch SW, ~S.
It is determined by the setting of W, for example, the speed setting switch SW.
Setting 1 means high speed (e.g. 6.0 km/h), and setting speed setting switch SW2 means medium speed, e.g. 4.5 km/h.
/h), and when the speed setting switch SW3 is set, low speed (
For example, the set speed is 1.5 Km/h), and the set speed is displayed by display lamps L4 to L6.

By the way, while the vehicle is running, the object detection sensor 19 is operating, and the control circuit 25 monitors the presence or absence of a detection signal from the object detection sensor 19 and distance data.

When no object is detected, the maximum speed mentioned above is set to the speed set by the setting switches SW+ to SW3, and the control circuit 25 operates the accelerator 8 as shown in FIG.
The vehicle speed is adjusted from 0 to V, (ma
control within the range of x).

When an object enters the detection area, the object detection sensor 19
detects this, the control circuit 25 limits the maximum speed based on the distance data. In other words, as shown in Figure 9, the detection distance range is divided into three stages: 0~l3, l, ~e2.12~l, and when object If the detection distance is within the range 12 to 11, the maximum speed (maX + ) is set to V,91@,
When the operating amount of the accelerator 8 is in the range of O to a, the vehicle speed is controlled accordingly from O to V, but when the operating amount of the accelerator 8 is in the range of a
Even if the vehicle speed exceeds Vl, the vehicle speed is limited to Vl. Similarly, when the detection distance is in the range l, ~12, the maximum speed max is v2, and when the detection distance is in the range O''''-Zs, the maximum speed max is ■,
Each is limited to

Further, in this embodiment, the detection area of the object detection sensor 19 is changed according to the current vehicle speed. For example, the vehicle speed is divided into two stages, and when the vehicle speed is low Va, the detection distance is set to 1a as shown in FIG. 10 <a>. The control circuit 25 outputs a distance control signal and a gain control signal to the object detection sensor 19 so as to shorten the width and narrow the width to Ma as shown in FIG. 10(b).

At high speed VB, the detection distance is increased to /b as shown in Figure 11 <a), and the width is increased to M as shown in Figure 10 (b>).
The control circuit 25 outputs a distance control signal and a gain control signal to the object detection sensor 19 so as to widen the distance as shown in b.

By changing the detection area according to the vehicle speed in this way, it is possible to achieve safe driving by applying the above-mentioned maximum speed limit safely and smoothly both at low speeds and at high speeds.

Further, if the vehicle collides with the object X while the maximum speed is limited and the vehicle body is not completely stopped, the collision sensor 14 is turned on and a collision detection signal is input to the control circuit 25. Regardless of the operation state of the accelerator 8, the control circuit 25 turns off the output of the motor drive signal, and at the same time turns off the output of the control signal to the brake drive circuit 23 to stop the rotation of the motor 5 and lock the electromagnetic brake 6. and stop running. In other words, it prevents accidents in the event of a collision. Here, as shown in FIG. 12, the control circuit 25 initializes and clears the internal timer when the collision sensor 14 is turned on, and also monitors the reverse operation of the accelerator 8. In other words, if there is a reverse operation after the vehicle stops, the control circuit 25 performs normal operation. Returning to operation control, the control circuit 25 outputs a motor drive signal to the motor drive circuit 22 to rotate the motor 5 in the reverse direction, thereby causing the vehicle to travel backward. If no reverse operation is performed and the collision sensor 14 continues to be on, the timer is cleared.

Then, the timer is repeatedly cleared until a reverse operation is performed or the collision sensor 14 is turned off. When the collision sensor 14 is turned off without performing a reverse operation, that is, when the collision state is canceled, a timer count is started from the cancellation point and is used as a standby time for shifting to normal operation control until the timer is counted up.

This waiting time is used for safety confirmation after the collision has been resolved, and this safety confirmation provides an extremely high level of safety.

By the way, the collision sensor 14 is provided at the center of the front end of the vehicle body 1 in the embodiment, but when the vehicle turns as shown by the broken line in FIG. If collision sensors 14' and 14' are attached to both front sides, it will be possible to cope with collisions when turning.

Furthermore, if the accelerator 8 is turned off during normal driving, the control circuit 25
By turning off the PWM output, the PWM output is reduced to zero, and after a certain period of time or when the vehicle speed reaches zero, the electromagnetic brake 6 can be locked to stop running.

Also, if you want to turn on the light 11, use the operation switch Sochi S.
It is only necessary to operate W4, and the operation switch SW4 turns on and off the light 11 by the control circuit 25 each time it is operated. Also, if you want to make the alarm buzzer 12 sound, just press and operate the operation switch SWs;
The quantity control circuit 25 whose Ws is pressed causes the alarm buzzer 12 to sound. Further, when the accelerator 8 is operated in the reverse direction to cause the vehicle to move backward, the control circuit 25 causes the alarm buzzer 12 to sound intermittently to issue an alarm.

[Effects of the Invention] The invention according to claim 1 includes an object detection sensor that detects an object within a detection area with its detection direction facing the traveling direction of a vehicle body, and a maximum speed that can be output when a detection signal from the object detection sensor is input. If there is an object within the detection area of the object detection sensor, the object detection sensor detects it, and the drive control means that receives the detection signal controls the maximum speed that can be achieved. This limit allows the vehicle to automatically control its speed even when the vehicle is traveling at a higher speed than the predetermined value, giving it enough time to apply braking before colliding with an object. This gives the user more room to avoid collisions by operating the steering wheel, making it easier for users such as physically disabled or elderly people to avoid collisions, and also allowing users to increase the speed due to careless operations and cause collisions with objects. As a result, injuries to passersby due to collisions can be prevented and safe driving can be achieved.

Further, in the invention according to claim 2, the predetermined value is set to be smaller as the distance to the object detected by the object detection sensor is shorter, so that the closer the detected object is, the lower the maximum speed is set to the predetermined value. This restriction has the effect of preventing the traveling speed from increasing beyond the speed at which collision with an object can be easily avoided, and enabling the -layer to travel safely.

Furthermore, since the invention as claimed in claim 3 is configured to change the detection area of the object detection sensor according to the traveling speed of the vehicle body, objects can be detected in the optimal detection area suitable for the speed, whether at low speed or high speed. This has the effect of allowing a smooth transition to safe driving when an object is detected.

The invention according to claim 4 includes a collision sensor that is attached to the vehicle body and detects a collision with an object, and a drive control means that stops traveling when a detection signal from the collision sensor is input. If the vehicle body collides with an object while driving, the collision sensor can detect this collision, and upon this detection, the drive control means will stop the vehicle, so it will automatically stop safely in the event of a collision with an object, and the collision will occur due to the collision. This has the effect of preventing accidents. In particular, according to the invention as set forth in claim 5, a collision between the front side of the vehicle body and an object that occurs when turning can be reliably detected by the front side collision sensor, and accidents caused by collisions when turning can be prevented.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention, FIG. 2 is a block diagram of the same, FIG. 3 is a top view of the handle part of the above, FIG. 4 is a side view of the accelerator of the above, and FIG. A partially omitted front view of the collision sensor used in the above, FIGS. 6(a) and 6(b) are operation explanatory diagrams of the collision sensor used in the above, FIG. 7 is a block diagram of the object detection sensor used in the above, and FIG. 8 is a Fig. 9 is an explanatory diagram of the relationship between the accelerator operation amount and vehicle speed as above, Fig. 9 is an explanatory diagram of the operation of the object detection sensor as above, Figs. 10 and 11 are illustrations of changes in the detection area of the object detection sensor as above, The figure is a flowchart for explaining control by the collision sensor used in the above, and FIG. 13 is an explanatory diagram of an example of arrangement of different collision sensors 0 in the same. 1 is a vehicle body, 5 is a motor, 6 is an electromagnetic brake, 8 is an accelerator, 14 is a collision sensor, 19 is an object detection sensor, 22 is a motor drive circuit, 23 is a brake drive circuit, and 25 is a control circuit. 1 is the vehicle body 19 is the object detection sensor (Figure 5) Figure 6 (Figure 10) Figure 11 (0) 1 is the vehicle body 14゜14' is the collision sensor Figure 13

Claims (5)

[Claims] (1) An object detection sensor that detects an object within a detection area with its detection direction facing the traveling direction of the vehicle, and a drive control means that limits the maximum speed that can be generated to a predetermined value when a detection signal from the object detection sensor is input. An electric wheelchair characterized by being equipped with. (2) The electric wheelchair according to claim 1, wherein the predetermined value is set smaller as the distance to the object detected by the object detection sensor is shorter. (3) The electric wheelchair according to claim 1, wherein the detection area of the object detection sensor is changed according to the traveling speed of the vehicle body. (4) An electric wheelchair characterized by comprising a collision sensor attached to a vehicle body to detect a collision with an object, and a drive control means that stops traveling when a detection signal from the collision sensor is input. (5) The electric wheelchair according to claim 4, wherein the collision sensor is attached to a front end portion and both front side surfaces of the vehicle body.