JP2006168489A - Power assisted transport vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power assisted transport vehicle equipped with a contact type sensor installed in such a range as accepting an access of an operator naturally even if his manner of gripping has changed, assuring easiness in manipulating in an emergency case, and allowing any unskilled operator to apprehend where a means for generating emergency stop exists. <P>SOLUTION: The power assisted transport vehicle is equipped with a handle installed at the side face of a vehicle body, a driving means to drive the vehicle body, a sensing means to sense energization of the vehicle body in the advancing or reversing direction with respect to the handle, a contact type sensor installed on the side face of the vehicle body where the handle is installed and having a sensing surface in a position accepting manipulation of an operator of mean figure when he manipulates the handle in the normal manipulating attitude, and a controlling means to actuate the driving means in accordance with the sensing result of the energization sensing means and control so as to apply brake to the actuation when contacting is sensed by the contact type sensor at the time of actuation. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a transport vehicle with a power assist function.

  Cars for transporting goods are widely used to be moved manually, but the larger the load weight, the greater the load, the more agile movement is difficult, and there is a problem that it is dangerous on slopes and steps. Have. Therefore, electric carts that can transport a large number of pallets, trays, and the like are used in catering and transportation in facilities such as hospitals and in product transportation in premises and production factories.

  The electric transport vehicle is an electric vehicle and is driven by the driving force of an electric motor. However, for example, an electric transport vehicle that is self-propelled by controlling the drive source by a switch operation is difficult to perform delicate operations, and skill is required for driving operation. Thus, a so-called power assist function transport vehicle (hereinafter referred to as a power assist transport vehicle) has been proposed in which the transport vehicle is moved manually and the human power is assisted by power such as an electric motor. This is because the vehicle body is provided with driving wheels for driving and driving wheels for steering, and drive units for driving these drive wheels, and according to the magnitude of external force applied to the operation unit (handle) provided on the vehicle body. The drive source of the driving wheel for driving and the driving wheel for steering is operated. In the power assist vehicle, the drive source is operated so that torque according to the magnitude of the external force is generated. Thereby, the load at the time of movement of a transport vehicle is greatly reduced.

As such a power assist cart, there is known a vehicle that can move back and forth by assisting human power by operating an operation unit attached to the cart (Patent Document 1). However, the power assist vehicle is easier to operate than the self-propelled electric vehicle, but is the same in that it is heavy. Therefore, it is desirable to improve the stopping means (increase in usability) and improve the steering performance (easy to change direction) in an emergency. Regarding improvement in usability, there has been known one having a control panel incorporating a control stick and an emergency stop switch (Patent Document 2).
JP 2002-326574 A ACT 6-27422

  However, according to such prior art, there are those equipped with an emergency stop switch, but the switch is small, the mounting position is not taken into consideration, and the switch is mixed with other switches in the control panel. There is also no consideration for the action that can be pushed by the bag in an emergency.

  Therefore, the present invention has an object to provide a means for emergency stop corresponding to a case where an emergency stop or the like is suddenly stopped in an emergency or the like in a power assist vehicle, and that is easy to understand even for those who are unfamiliar with the operation.

  In the power assist vehicle according to the first aspect of the present invention, a handle disposed on a side surface of the vehicle main body, drive means for driving the vehicle main body, and biasing of the vehicle main body in the forward or reverse direction with respect to the handle. A detecting means for detecting and a side surface of the vehicle main body on which the handle is disposed, and a position at which an average operator can operate when operating the handle in a normal operation posture. The contact-type sensor having the detection surface and the drive means are driven according to the detection result by the bias detection means, and when the contact is detected by the contact-type sensor during the drive, the drive is braked. And a control means for controlling the operation.

  According to a second aspect of the present invention, in the power assist vehicle according to the first aspect, the detection surface of the contact-type sensor is operated at least when the operator operates the handle in a normal operation posture. It is arrange | positioned in the position which reaches from a person's both hands simultaneously.

  According to a third aspect of the present invention, in the power assist vehicle according to the second aspect, the detection surface of the contact-type sensor is arranged at a position about the height of the operator's chest.

  According to a fourth aspect of the present invention, in the power assist vehicle according to the third aspect, the detection surface of the contact-type sensor is divided or separated into a region on the right hand side and a region on the left hand side of the operator. Features.

  According to a fifth aspect of the present invention, in the power-assisted transport vehicle according to the third aspect, the detection surface of the contact-type sensor is composed of one region having a width equal to or greater than the width of the handle. To do.

  According to a sixth aspect of the present invention, in the power assist vehicle according to the third aspect, the detection surface of the contact-type sensor is composed of one region having substantially the same width as the side surface on which the handle is disposed. It is characterized by.

  A seventh aspect of the present invention is the power assist vehicle according to any one of the first to sixth aspects, wherein the detection surface of the contact-type sensor simultaneously constitutes a cover of the side surface of the vehicle.

  According to an eighth aspect of the present invention, in the power assist vehicle according to any one of the first to seventh aspects, when the contact is detected by the contact sensor, the control means is based on the detection result of the bias in the detection means. The predetermined size is reduced.

  According to a ninth aspect of the present invention, in the power assist vehicle according to any one of the first to eighth aspects, the control means detects the urging of the handle when the operator pulls and drives the vehicle. When the means detects, when the contact is detected by the contact sensor, the drive is braked to stop the movement of the vehicle. It is desirable that the vehicle stop moving immediately.

  According to the first aspect of the present invention, in the drive control (power assist control), the contact type sensor used for braking the drive at the time of emergency stop is arranged on the side surface where the handle of the power assist vehicle body is provided. In addition, it has a detection surface at a position where it can be operated in a normal operation posture when the average operator is operating the handle, so that even if the handle changes, the operator can naturally reach the range There is a type sensor, and it is easy to operate in the event of a drought in an emergency, etc., and even for those unfamiliar with the operation, the means for emergency stop is easy to understand.

  In such an invention, as in the invention of claim 2, at least when the operator is operating the handle in the normal operation posture, the detection surface of the contact-type sensor is disposed at a position that can reach from both hands of the operator at the same time. can do. In this case, since the contact type sensor exists in a range where the operator's hand can reach naturally, the operability in an emergency or the like can be improved.

  At this time, as in the invention of claim 3, the detection surface of the contact type sensor can be arranged at a position about the height of the chest of the operator.

  Further, as in the invention of claim 4, the detection surface of the contact type sensor may be divided or separated into a right hand side region and a left hand side region of the operator.

  Furthermore, as in the invention of claim 5, the detection surface of the contact-type sensor can be configured from one region having a width at least equal to the width of the handle.

  In addition, as in the invention of claim 6, the detection surface of the contact-type sensor can be constituted by one region having substantially the same width as the side surface on which the handle is disposed.

  According to the seventh aspect of the present invention, the detection surface of the contact-type sensor simultaneously forms the cover of the side surface of the power-assist vehicle, so that the detection surface can be expanded to the entire cover, and the contact can be detected. The range can be expanded.

  According to the inventions of the second to seventh aspects, the operability in the case of a drought such as an emergency, and the ease of understanding the means of emergency stop for a person unfamiliar with the operation are improved.

  According to the eighth aspect of the present invention, for example, when the vehicle is moving backward when the handle is disposed on the rear surface, if the contact is detected by the contact sensor during the backward driving, the detection is performed. A predetermined magnitude can be subtracted from the urging in the reverse direction, and the drive control can be performed using the result.

  When the power-assisted transport vehicle is moving backward, drive control to reverse travel of the transport vehicle is performed by detecting the urging in the reverse direction with respect to the handle. At that time, when contact is detected by the sensor, a reaction force due to the contact is further superimposed on the urging force in the backward direction. However, for example, when the contact type sensor is used not to issue a stop command to the motor but to reduce the driving force with respect to the drive during an emergency stop, the detection value on which the reaction force is superimposed is detected. The drive control with reduced driving force is performed while using. As a result, although a stop is intended, an excessive driving force is generated in the reverse direction, and there is a possibility that a torque against the intention of the operator may be generated in the transport vehicle. In particular, the greater the contact with the contact sensor, the greater the pressing force at the time of contact, and the greater the reaction force at the same time, so a large torque tends to remain in the reverse direction. In this case, it may be assumed that the operator's response to the reverse drive is not in time.

  Therefore, in such a case, by reducing the predetermined magnitude from the superimposed bias in the reverse direction as in the invention of claim 8 and performing the drive control using the result, it is not intended by the operator. The influence of force superposition can be reduced.

  Further, in the above-described example in which contact is detected by the contact sensor when the handle is disposed on the rear surface and the transport vehicle is driven backward, the movement of the vehicle is stopped as in the invention of claim 9. The movement of the vehicle not intended by the operator can be reduced. This is more effective as the vehicle stops moving immediately.

  The significance or effect of the present invention will become more apparent from the following description of embodiments.

  However, the following embodiment is merely one embodiment of the present invention, and the meaning of the term of the present invention or each constituent element is not limited to that described in the following embodiment. Absent.

  Embodiments of the present invention will be described below with reference to the drawings. In the following, a description will be given by taking an example of a service vehicle such as a hospital.

  First, FIG. 1 shows a perspective view of the entire power assist distribution vehicle according to the embodiment.

  In the figure, the direction of the arrow is the forward direction of the carriage, and the surface with the operation handle in front is the rear surface. When the operator of the arrangement vehicle pushes this operation handle, the carriage advances in the forward direction. The power assist operation is realized by detecting the force applied to the operation handle and performing control by a signal conversion unit built in the vehicle body.

  Further, a contact type sensor (hereinafter referred to as a stop switch) having a detection surface is provided above the rear surface. The stop switch is arranged in a position where the operator can easily push it into the heel in an emergency (such as the height of a person's chest) and in a mode (such as a form sufficiently larger than the palm of a person). The detection surface of the stop switch constitutes the vehicle side (rear) cover at the same time. The detection surface may be plural, such as being divided or separated into an area on the right hand side and an area on the left hand side of the operator. Further, as shown in the figure, it may be composed of one region having a width equal to or larger than the width of the handle, or may be approximately the same width as the side surface on which the handle is arranged.

  In this arrangement vehicle, two free caster wheels and two drive wheels are provided near the four corners of the arrangement vehicle bottom surface to support the arrangement vehicle body. These drive wheels are respectively attached to left and right independent motors that are driven to rotate in forward and reverse directions.

  The arrangement vehicle is controlled so that two motors that rotate and drive the driving wheels that support the vehicle body in the forward and reverse directions are rotated forward or backward by operating the operation handle mounted on the body. Is configured to move forward or backward. Note that the power assist operation is performed to the right or left according to the operation of the operator depending on the difference in the output torque amount between the two motors.

  FIG. 2 shows a hollow rubber switch and a mechanical switch as examples of the stop switch. In both cases, contact is detected in two states of ON / OFF. In addition, a pressure-sensitive rubber switch, a capacitive switch, or the like can be used.

  The operation handle will be described with reference to FIG.

  FIG. 4A is a perspective view of the vicinity of the operation handle of the carriage. The operation handle has one handlebar and two force detectors connected to form a “U” shape (symmetrical), and force detectors are provided at both ends of the handlebar. It has been.

  FIG. 4B is a top view (inside) for explaining the connection between the handlebar and the force detection unit, and FIG. 4C is a perspective view showing the internal structure of the force detection unit. A handlebar joint, a force sensor (for example, a load cell), and a preload spring are provided inside the force detector. FIG. 4D is a perspective view showing the end face structure of the handle bar. A U-shaped notch is provided on the end surface of the handle bar, and is fitted into the protrusion of the handle bar joint portion. The component force of the external force applied to the handle bar is transmitted to the handle bar joint portion through the notch. Further, the handlebar joint portion extends to the force sensor in the force detection portion, and the force applied to the handlebar joint portion is transmitted to the force sensor. The preload spring is fitted on the handlebar joint portion, and generates a certain force (preload) that presses the handlebar joint portion against the force sensor. That is, the force sensor is pressurized by the preload spring even when the component force due to the external force is zero, and as a result, even when a pulling force is applied to the handlebar, the pulling force can be detected by the force sensor. . That is, when the operator pushes the handlebar, the force sensor is added with the force of the preload spring and the force pushing the handlebar. When the operator pulls the handlebar, the force sensor A force obtained by subtracting the handlebar pulling force from the force is applied.

  As described above, the operator's operating force applied to the handlebar is divided and detected by the left and right force sensors, so that the operator can move the cart by himself by pushing or pulling the handlebar. On the other hand, power assist has been realized. That is, according to the position, direction, and size of the external force applied to the handlebar, the external force is divided into each force detection unit, and the force is detected by each force sensor. For example, when the left hand side of the operation handle is pushed strongly in the same way as a non-electric hand cart to perform a right turn, the force detected by the force sensor built in the left / right force detection unit provided on the operation handle is “Left hand side> right hand side” is detected, and “left hand side motor drive torque> right hand side motor drive torque” is established, and a right turn is realized.

  Next, referring to FIG. 4, a block diagram of the electric control system in the present embodiment is shown. From the same figure, 1 and 2 are the above-mentioned force sensors, and 3 is a stop switch. Reference numeral 10 denotes a left wheel motor, and 20 denotes a right wheel motor. 100 is a signal conversion unit (left part) that processes electric signals from the force sensor 1 and the stop switch 3 and outputs a control signal (motor current) to the motor 10, and 101 is an analog corresponding to the operation force from the force sensor 1. AD converter for converting a typical electrical signal into a digital value, 102 a CPU for calculating a signal based on a program stored in advance, and 103 a motor for controlling a motor current based on a torque drive signal calculated by the CPU 102 It is a control unit. 200 is the same as the signal conversion unit 100, a signal conversion unit (right part) that processes electric signals from the force sensor 2 and the stop switch 3 and outputs a control signal (motor current) to the motor 20, 201 is a force An AD conversion unit that converts an analog electrical signal corresponding to the operation force from the sensor 2 into a digital value, 202 is a CPU that calculates a signal based on a program stored in advance, and 203 is a torque calculated by the CPU 202 It is a motor control part which controls a motor current based on a drive signal.

  In the figure, when the operator touches the stop switch 3 when the force sensor 1 is pressurized, the CPUs 102 and 202 control the motor control units 103 and 203 so as not to output the motor current. The torque generation in the left motor 10 and the right motor 20 is stopped. As a result, since the operator who intends to stop does not apply the operation force to the operation handle, the operation is stopped by the dynamic friction due to the weight of the layout vehicle. In addition to stopping the motor, the predetermined magnitude may be reduced with respect to the torque depending on the operating force, and the torque may be generated in the direction of braking the operation of the motor. When the arrangement vehicle is equipped with a braking function such as an electromagnetic brake, the braking function may be used to actively urge the arrangement vehicle to stop.

  Next, the operation flow of the signal conversion unit 100 will be described with reference to the flowchart of FIG. The operation flow of the signal conversion unit 200 is also the same, and thus the description thereof is omitted.

  Now, when the power switch of the layout vehicle is turned on, the flow starts. As a result, in the figure, the flow moves from start to step S100.

  In step S100, an external force (operation force) applied to the force sensor 1 when the operator presses the handlebar is detected.

  In step S101, it is determined whether or not the operator has touched the stop switch 3. When it is determined that there is no contact, the flow proceeds to step S102, and when it is determined that there is a contact, the flow proceeds to step S103. In this branch, it is determined that the operator has touched the stop switch 3 only while the stop switch 3 is being pressed. Therefore, if contact with the stop switch 3 is not detected, it is determined that the operator is not in contact with the stop switch 3. In this branch, once it is determined that the operator has touched the stop switch 3, it may be determined that the operator continues to touch the stop switch 3 thereafter. In this case, it is necessary to provide a mechanism for determining that the contact with the stop switch 3 has been eliminated by a procedure for canceling the determination (not shown). For example, a release switch or the like may be provided as a release procedure.

  In step S <b> 102, the CPU 102 outputs a torque drive signal corresponding to the operation force (component force) detected in step S <b> 100, and the motor current corresponding to the motor current is output from the motor control unit 103 to the motor 10. As a result, the moving operation of the arrangement vehicle is power-assisted with a driving force corresponding to the operating force of the operator.

  In step S <b> 103, the CPU 102 controls the motor control unit 103 to stop the motor current output to the motor 10.

  In step S104, when the power switch is turned off, the flow ends, and otherwise, the flow returns to step S100. Thereafter, the flow described so far is repeated.

  In FIG. 5, when the operator touches the stop switch 3 in step S103, the CPU 102 controls to stop the motor current output to the motor 10 and stop the motor. 3 may be controlled so that the torque of the motor 10 is reduced. FIG. 6 is a flowchart of the operation of the signal conversion unit 100 in the case of control for reducing the torque of the motor 10. The operation flow of the signal conversion unit 200 is also the same, and thus the description thereof is omitted.

  In the figure, it is the same as FIG. 5 except that step S103 is changed to step S105. In step S105, the CPU 102 outputs a torque drive signal for reducing the torque of the motor 10 to 1 / K by the input of the stop switch 3 (that is, “operation force × force coefficient / K → torque drive signal”; K is an experiment or the like) The motor current corresponding to the motor current is output from the motor control unit 103 to the motor 10.

  As a result, it is possible to reduce the abruptness when the distribution vehicle stops. That is, it is possible to cause a slight time delay until the arrangement vehicle stops. For example, even when the operator accidentally touches the stop switch 3 while moving the arrangement vehicle forward (the stop switch 3 is For example, when the entire area above the rear surface of the layout vehicle is occupied, the operator can make unintentional contact with the stop switch 3).

  Here, in the case of FIG. 6, a case will be described in which the operating handle is pulled back to move the arrangement vehicle backward. In this case, when the stop switch 3 is touched, as shown in the lower diagram of FIG. 7 (a diagram for explaining the external force detected by the force sensor when the operation force is the pulling force), the force for pressing the stop switch 3 Becomes a force that pushes the vehicle body, and the reaction force causes an operation force not intended by the operator to be applied to the operation handle. As a result, there is a possibility that the arrangement vehicle moves in an unexpected direction of the operator.

  Further, in the case where it is determined that the operator continues to touch the stop switch 3 until it is determined that the operator has touched the stop switch 3 until a specific release procedure is executed. It is also conceivable that more torque than intended by the operator may continue to be generated during that time.

  Therefore, as shown in FIG. 8, the amount of force for pressing the stop switch 3 obtained from the stop switch 3 is subtracted from the amount detected by the force sensor or when the stop switch 3 is a pressure sensitive switch. By subtracting the result, the detection result of the force sensor is obtained, and correction is performed so as to approach the operating force intended by the operator. Thereby, the torque generation beyond the intention in the reverse direction can be suppressed, and the stop operation intended by the operator can be realized.

  Specifically, step S106 and step S107 are added to the figure compared to the case of FIG. The other steps are the same as in FIG.

  In step S106, it is determined whether or not the external force on the operation handle is a pulling force. If the pulling force is the pulling force, the process moves to step S107. If the pulling force is not the pulling force, the process moves to step S105.

  In step S107, the CPU 102 calculates a value obtained by subtracting a certain amount (α) from the amount detected by the force sensor by the input of the stop switch 3, and then reduces the torque of the motor 10 to 1 / K using the value. A torque drive signal is output (that is, “(operation force−α) × force coefficient / K → torque drive signal”), and a motor current is output from the motor control unit 103 to the motor 10.

  FIG. 8 is a flowchart of the operation of the signal conversion unit 100. Since the operation flow of the signal conversion unit 200 is the same, the description thereof is omitted.

  The embodiments of the present invention can be appropriately modified in various ways within the scope of the technical idea shown in the claims.

It is a perspective view of the whole power assist distribution vehicle concerning an embodiment. It is a figure which shows the example of the stop switch which concerns on embodiment. It is a figure explaining the operation handle concerning an embodiment. It is a block diagram of the electric control system which concerns on embodiment. It is a figure explaining the operation | movement flow of the signal conversion part which concerns on embodiment. It is a figure explaining the operation | movement flow of the signal conversion part which concerns on embodiment. It is a figure explaining the external force detected by a force sensor, when the operation force which concerns on embodiment is a pulling force. It is a figure explaining the operation | movement flow of the signal conversion part which concerns on embodiment.

Explanation of symbols

1 Force sensor (left)
2 Force sensor (right)
3 Stop switch 10 Motor (left)
20 Motor (right)
100 Signal converter left part 102 CPU
103 Motor control unit 200 Signal conversion unit right part 202 CPU
203 Motor controller

Claims (9)

A handle arranged on the side of the vehicle body,
Drive means for driving the vehicle body;
Detecting means for detecting an urging force of the vehicle main body in the forward direction or the reverse direction with respect to the handle;
A contact that is arranged on a side surface of the vehicle body on which the handle is disposed and has a detection surface at a position where an average operator can operate the handle in a normal operation posture. Type sensor,
Control means for driving the drive means in accordance with the detection result by the bias detection means, and for controlling the drive to be braked when contact is detected by the contact-type sensor during the drive.
A power assist vehicle characterized by that. In claim 1,
The detection surface of the contact-type sensor is disposed at least at a position that can be reached simultaneously from both hands of the operator when the operator is operating the handle in a normal operation posture.
A power assist vehicle characterized by that. In claim 2,
The detection surface of the contact sensor is disposed at a position about the height of the operator's chest,
A power assist vehicle characterized by that. In claim 3,
The detection surface of the contact sensor is divided or separated into a right hand side region and a left hand side region of the operator,
A power assist vehicle characterized by that. In claim 3,
The detection surface of the contact type sensor is composed of at least one region having a width equal to or greater than the width of the handle.
A power assist vehicle characterized by that. In claim 3,
The detection surface of the contact-type sensor is composed of one region having substantially the same width as the side surface on which the handle is disposed.
A power assist vehicle characterized by that. In any one of Claims 1 thru | or 6,
The detection surface of the contact sensor constitutes a cover of the vehicle side surface at the same time,
A power assist vehicle characterized by that. In any one of Claims 1 thru | or 7,
When the contact is detected by the contact sensor, the control means subtracts a predetermined size from the detection result of the bias in the detection means.
A power assist vehicle characterized by that. In any of claims 1 to 8,
The control means brakes the driving when the detection means detects contact with the handle when the operator pulls and drives the vehicle to pull the vehicle and the contact is detected by the contact sensor. To stop the movement of the vehicle,
A power assist vehicle characterized by that.

Images