JP2011245958A - Carrier with power assist - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve stable power assist control with easy operation while reducing operator's anxiety, in a carrier with power assist.SOLUTION: The carrier 1 includes: a vehicle body 2; a driving ring 3 for linearly turn-moving the vehicle 2; a driving section 4 for driving the driving ring 3; a handle 5 for operation; a two-axial force sensor which detects external force (operating physical force) applied to the handle 5 (not illustrated); and a controller 6 for applying power assist control for the driving section 4 so that driving force may be generated according to the operating physical force on the basis of a signal output by the two-axial sensor, The handle 5 is provided so that an operation position of the operator M may become slant in front of the vehicle body 2. Thereby, the operator M operates the carrier 1 by sitting at a position of a good view of a front and rear place outside of a progressing path of the carrier 1.

Description

  The present invention relates to a power assisted transport vehicle.

  Conventionally, a power assisted transport vehicle 9 as shown in FIG. 11 is known (see, for example, Patent Document 1). This transport vehicle 9 includes a driving wheel 91 and a handle 93 with a force sensing function on a vehicle body 90. When the operator M operates the handle 93, a driving force corresponding to the operating force is generated in the driving wheel 91. . The handle 92 is disposed at the front center of the vehicle body 90. The worker M can freely move the heavy vehicle 9 with a slight force by pulling the handle 92 from the front or applying a slight force in the direction of turning the vehicle body 90 to the handle 92. It can be stopped with a slight force as well.

Japanese Patent No. 3032698

  However, in the transport vehicle 9 as described above, although the operation is light by the power assist function, there is a problem to be improved so that the operation can be performed more comfortably. The transport vehicle 9 moves from the rear position, which is the blind spot of the worker M, toward the worker M because the weight of the actual vehicle body 90 is very heavy against the sense of operation. May occur. For example, if the transport vehicle 9 moves forward unintentionally due to an unexpected operation, the operator M may be bumped or pinched. Inadvertent operation may occur when the operator M turns around a corner, or when the operator leans on the side of the transport vehicle 9 while grasping the handle 92 in order to confirm the rear of the transport vehicle 9. It is likely to occur when the posture changes from the normal posture. For example, as shown in FIG. 12A, in the normal operation state, an assist force Fa that does not feel strange is generated on the drive wheels 91 in accordance with the operation force Fi detected by the force sensing function of the handle 92. However, in the case of FIG. 12B, as a result of the operator M operating from the side due to rearward confirmation and anxiety, the elbow of the operator M contacts the vehicle body 90, and the contact force Fc resulting from the contact is the vehicle body 90. Has been affected. The operator M feels that the transport vehicle 9 does not accelerate or decelerate in a state where the operation force Fi is balanced with the contact force Fc. However, even if the forces Fi and Fc are balanced, an assist force Fa corresponding to only the force Fi detected by the force sensing function of the handle 93 is generated in the transport vehicle 9. For this reason, contrary to the operator's M operation intention, the transport vehicle 9 may accelerate ahead.

  The present invention solves the above-described problems, and an object thereof is to provide a power-assisted transport vehicle capable of reducing anxiety of an operator and realizing stable power assist control with an easy operation.

  In order to achieve the above object, a power-assisted transport vehicle according to the present invention includes a vehicle body, a drive wheel that linearly moves and turns the vehicle body, a drive unit that drives the drive wheel, an operation handle, and a handle. A biaxial force sensor that detects the applied external force with at least two axial components, and a power that causes the drive unit to generate an assist force for linear movement or turning movement according to the external force detected by the biaxial force sensor And a control unit that performs assist control, and the handle is provided such that the operation position of the operator is obliquely forward or obliquely behind the vehicle body.

  In this power assisted transport vehicle, it is preferable that the control unit cancels a turning moment generated due to the steering of the steering wheel being deviated from the center of the vehicle body, and performs power assist control.

  In this power assisted transport vehicle, the handle is preferably provided on the front or rear surface of the vehicle body, the side surface of the vehicle body, or the upper surface of the vehicle body.

  In the power assisted transport vehicle, the handle is preferably provided on the left and right sides of the vehicle body.

  In this power assisted transport vehicle, the control unit preferably uses the sum of external forces applied to the left and right handles for power assist control.

  In this power-assisted transport vehicle, the handle includes a touch sensor that detects that the operator has gripped, and the control unit uses the external force applied to the handle detected by the touch sensor as a valid external force. It is preferable to perform assist control.

  In this power-assisted transport vehicle, the handle is provided at the front and rear of the vehicle body, and the control unit enables the external force applied to only one of the front and rear handles to be applied to both the front and rear handles simultaneously. It is preferable to perform power assist control by disabling all external forces applied, enabling all external forces, or enabling only one of the front and rear external forces.

  According to the power assisted transport vehicle of the present invention, the operator can position the handle in a place with good visibility before and after moving away from the travel path of the transport vehicle, thereby reducing anxiety of the operator. In addition, stable power assist control can be performed with an easy operation.

1 is a plan configuration diagram of a power assisted transport vehicle according to a first embodiment of the present invention. The top view which shows the relationship between the operating force and power assist force in the transport vehicle. (A)-(f) is a perspective view which shows arrangement | positioning of the handle | steering-wheel in the same transport vehicle. (A) (b) is a perspective view which shows other arrangement | positioning of the handle | steering_wheel in the same transport vehicle. The plane block diagram of the power assisted conveyance vehicle which concerns on 2nd Embodiment. (A)-(d) is a perspective view which shows arrangement | positioning of the handle | steering-wheel in the same transport vehicle. The top view which shows the operation force in the transport vehicle. The top view which shows the example of the use condition of the transport vehicle. (A) is a perspective view of the power assisted transport vehicle according to the third embodiment, and (b) is a plan view of the transport vehicle. The perspective view of the handle | steering-wheel of a power assisted conveyance vehicle. The perspective view of the conventional power assisted conveyance vehicle. (A) (b) is a perspective view which shows the use condition of the transport vehicle.

Hereinafter, a power assisted transport vehicle according to an embodiment of the present invention will be described with reference to the drawings.
(First embodiment)
1 and 2 show a power-assisted transport vehicle 1 according to a first embodiment. As shown in FIGS. 1 and 2, a power assisted transport vehicle 1 (hereinafter simply referred to as a transport vehicle 1) is added to the vehicle body 2, the drive wheel 3, the drive unit 4, the handle 5, and the handle 5. A biaxial force sensor (not shown) that detects and outputs operating forces Fx and Fy, which are external forces, and a control unit 6 are provided. The drive wheel 3 is driven by the drive unit 4 to move the vehicle body 2 linearly and turn. The handle 5 is operated by the operator M in order to stop the transport vehicle 1 from moving. The biaxial force sensor detects and outputs operating forces Fx and Fy that are external forces applied to the handle 5. Based on the signal output from the biaxial force sensor, the control unit 6 generates each driving unit so as to generate a driving force that becomes the assisting force Fa or Ma for linear movement or turning movement in accordance with the operation forces Fx and Fy. 4 is controlled. Control that generates assist force by the control unit 6 is referred to as power assist control. The handle 5 is provided on the vehicle body 2 so that the basic operation position of the operator M is obliquely in front of the vehicle body 2. In other words, the handle 5 can be disposed, for example, in a region of the vehicle body 2 surrounded by the dotted line A in FIG. A white arrow x indicates a main movement direction (forward direction) of the transport vehicle 1. More generally, the handle 5 may be provided at a position deviated from the center line in the front-rear direction to the left or right when viewed from the center of the vehicle body 2.

  In the transport vehicle 1, for example, four drive wheels 3 that can move in all directions are driven by four drive units to move straight forward and turn. In addition, as a configuration composed of two drive wheels 3 and auxiliary wheels provided one by one on the left and right, it may be caused to go straight or turn depending on the difference in rotational speed between the left and right drive wheels 3. Further, the biaxial force sensor only needs to be able to detect an operation force applied to the handle 5 in at least two different directions in the plane in which the transport vehicle 1 moves, for example, a strain gauge that detects a change in electrical resistance. Etc. can be configured. In addition, a strain gauge using a magnetostrictive film, a torsion detection gauge, or the like can be used. Further, a configuration for detecting deformation or displacement of the handle 5 due to an operating force, a pressure sensor for detecting an operating force as a pressure change, or the like. It is good also as a structure to use.

Next, the operation for the power assist control of the control unit 6, that is, the setting of the assist force based on the operation force will be described. As shown in FIG. 2, the mounting position of the handle 5 is a distance Ly from the turning center C of the vehicle body 2 toward the front direction x and a distance Lx toward the lateral direction y orthogonal to the direction x. Suppose that there is a point of operation force. When the operation force is detected as two components of the operation force Fx along the direction x and the operation force Fy along the direction y, the force around the turning center C by these operation forces (Fx, Fy) The moment M is M = Fy × Ly−Fx × Lx. Therefore, when the force obtained by simply amplifying the operation force is used as the assist force, if the amplification factor (assist gain) is g, the assist force Fa for rectilinear movement and the assist force Ma for turning movement are calculated by simple calculation. In this case, it is expressed by the following formula.
Fa = g × Fx,
Ma = g × (Fy × Ly−Fx × Lx) (in the case of simple calculation).

However, in order to move the transport vehicle 1 straight forward, it is necessary to set Ma = 0. In the above formula, in order to set Ma = 0, Fx and Fy must be skillfully adjusted at the same time. This is because the handle 5 is provided so that the basic operation position of the operator M is obliquely in front of the vehicle body 2, in other words, the handle 5 is arranged offset from the center line in the front-rear direction of the vehicle body. This is due to the existence of the distance Lx caused by Therefore, the control unit 6 performs power assist control on the drive unit 4 so as to suppress or cancel the generation of the assist force for turning movement based on the operation force Fx in the straight traveling direction (that is, the assist force based on Fx × Lx). To do. In brief, as shown in the following formula, by setting Lx = 0, the assist force based on Fx × Lx is canceled and Ma is optimized.
Ma = g × (Fy × Ly) (in the case of proper calculation).

The calculation of the above formula is calculated based on the assumption that the position of the handle 5 (the position of the operating point of the operating force on the vehicle body 2) is on the center line in the front-rear direction of the vehicle body 2, or It can be considered that the calculation assumes that C is directly behind the operation position. Such setting of the assist force eliminates the need for the operator M to adjust the operation force Fy in the left-right direction so that unnecessary turning force is not generated, and the operator M can easily advance the transport vehicle 1 straight. Can do. In addition, instead of setting Lx = 0, Ma may be calculated by the following equation using an adjustable turning assist force correction coefficient k (0 ≦ k ≦ 1). The magnitude of the coefficient k may be set based on the actual operation of the transport vehicle 1 so as to reduce the feeling of strange operation.
Ma = g × (Fy × Ly−k × Fx × Lx).

  Next, a specific arrangement and shape of the handle 5 in the transport vehicle 1 will be described with reference to FIGS. As shown in FIGS. 3A to 3F, the handle 5 of the transport vehicle 1 includes a front surface, a side surface, an upper surface, a ridge line portion between the front surface and the side surface, a ridge line portion between the side surface and the upper surface, and the like. It is a two-point fixed handle that is fixed at a position with its gripping portion horizontal or vertical. The handle 5 is not limited to the arrangement shown here, and can be installed on the vehicle body 2 in any arrangement or posture. The handle 5 shown in FIG. 4A is an example of an arrangement embedded in the corner of the vehicle body 2, and the handle 5 shown in FIG. 4B is an example of a handle fixed at one point. 3 and 4, the basic operation position of the operator M is assumed to be obliquely forward of the vehicle body 2, and the main operation direction is shown to be the forward pulling direction indicated by the arrow x. Has been. The arrangement of the handle 5 is not limited thereto, and the handle 5 may be provided so that the basic operation position of the operator M is obliquely behind the vehicle body 2.

  According to the present embodiment, the operator M may operate the handle 1 by operating the handle 5 diagonally in front of the transport vehicle 1 and pulling the transport vehicle 1, and positioning the vehicle 1 in a place where the front and rear visibility is good. Can do. Therefore, an unreasonable posture different from the normal operation, for example, an operation performed by getting out of the body or an unexpected operation of the transport vehicle 1 due to such an operation is less likely to occur, and the operator's anxiety is reduced and stable. Power assist control can be realized. Further, since the operator M can operate at a position off the traveling path of the transport vehicle 1, the feeling of pressure from the transport vehicle 1 and the anxiety about rear-end collision or pinching can be eliminated, and a sense of security of operation can be realized. . The basic operation position of the handle 5 is obliquely in front of the vehicle body 2, but can be operated from directly in front of the vehicle body 2 or from the side. Therefore, by providing the handle 5 on the side surface or the upper surface so as not to protrude from the front surface side of the vehicle body 2, the front surface of the transport vehicle 1 can be parked close to the wall or another transport vehicle. Similarly, by providing the handle 5 on the front surface or the upper surface so as not to protrude from the side surface of the vehicle body 2, the side surface of the transport vehicle 1 can be parked near the wall or another transport vehicle, and the space is narrow. It is easy to run along the passage and close to the wall. The handle 5 may be provided on the vehicle body 2 so that the basic operation position of the operator M is obliquely behind the vehicle body 2. In this case, the operator M may operate the handle 5 by a pushing operation, or may perform an operation of pulling the handle 5 while being positioned to the side of the rear side of the vehicle body 2.

(Second Embodiment)
5 to 8 show a power-assisted transport vehicle 1 according to the second embodiment. As shown in FIG. 5, the transport vehicle 1 according to the present embodiment is provided with the handle 5 symmetrically on the left and right of the vehicle body 2 in the first embodiment. Examples are shown in FIGS. 6 (a) to 6 (d). In the example arranged in the front surface as shown in FIG. 6 (a) and the example arranged in the upper surface as shown in FIG. 6 (d), the handle 5 does not protrude from the side surface. It is easy to run close to narrow passages and walls. Further, since the handles 5 are provided on the left and right, the operator M can operate from either the left or right front of the transport vehicle 1 regardless of the dominant hand, and is easy to use. The arrangement of the handle 5 is not limited to left-right symmetry, and the handle 5 may be arranged in the front-rear direction so as to be diagonally arranged in a plan view with respect to the vehicle body 2.

  In the transport vehicle 1 having the left and right handles 5 as described above, it is preferable that the control unit 6 performs power assist control of the drive unit based on the resultant force of the operation force applied to the left and right handles. For example, in the case of the two handles 5 shown in FIG. 7, the control unit 6 calculates the sum of the force Fx1 and Fx2 in the x and y directions and the force Fy1 and Fy2 in the lateral direction with respect to the respective vehicle bodies 2 as Fx. = Fx1 + Fx2, Fy = Fy1 + Fy2, and the resultant force (Fx, Fy) is obtained. The control unit 6 assumes that the resultant force (Fx, Fy) acts on the center position of the two handles 5, and based on the resultant force (Fx, Fy), the assist force Fa, Ma for linear movement or turning movement Each drive unit 4 is subjected to power assist control so as to generate a driving force. According to the configuration using such a resultant force, as shown in FIG. 8, by operating with both handles 5, the transport vehicle 1 is stabilized in the pushing direction from the front (the direction opposite to the forward direction x). It can be operated and moved in the state.

(Third embodiment)
FIGS. 9A and 9B show a power-assisted transport vehicle 1 according to the third embodiment. The transport vehicle 1 of this embodiment is provided with a total of four handles 5, one on each of the left and right sides of the vehicle body 2. The control unit 6 validates the operation force applied only to either the front or the rear of the vehicle body 2. In addition, regarding the operation force applied to both the front and rear handles 5 of the vehicle body 2 at the same time, the control unit 6 determines whether to invalidate all operation forces or validate all operation forces according to a predetermined setting. Only the operating force in either the front or rear is valid. The control unit 6 performs power assist control of the drive unit 4 in accordance with the effective operation force. Whatever control method is used, that is, the “predetermined setting” may be set according to the purpose of use of the transport vehicle 1 or the usage environment, and the operation status, for example, whether the vehicle is moving or not, and its speed. The setting can be changed dynamically depending on the case. For example, when a plurality of workers M work before and after the vehicle body 2 and use the transport vehicle 1, a stronger operating force may be effective as long as safety and other circumstances are not adversely affected. it can. Note that the number of handles 5 is not limited to four, and may be one at the front and rear, or one or more at the front and rear (for example, the upper surface, the side surface, the front surface, or the rear surface).

  According to the present embodiment, since the front and rear handles 5 can be operated from either the front or the back, when the obstacle is approached to the last minute and stopped, the front or the rear is easily operated. It can be selected and operated, and an easy-to-use transporter can be realized. Further, by determining whether the front and rear operating forces are valid / invalid according to a predetermined setting, it is possible to prevent the occurrence of problems due to accidental operations, and to realize a transport vehicle that can perform convenient and reliable operations.

(Composition of handle)
FIG. 10 shows the handle 5 used in the transport vehicle 1 in the first, second, and third embodiments. The handle 5 includes a touch sensor 5a that detects that the operator M has gripped it. The control unit 6 performs power assist control on the drive unit 4 using only the operation force applied to the handle 5 detected to be gripped by the touch sensor 5a as an effective operation force. The touch sensor 5a can be configured using, for example, a reflective optical proximity sensor, an optical interrupter, or the like. These optical sensors detect gripping by detecting reflected light from a hand held by the operator M holding the handle 5 or detecting a state where the operator M is shielded by the hand. The touch sensor 5a is not limited to these, and can be configured using an arbitrary sensor such as a mechanical type, an electric type, a magnetic type, or a combination thereof. According to such a configuration using the handle 5 and the control unit 6, it is possible to ignore a noise component generated in the biaxial force sensor of the handle that is not operated. For example, when the vehicle 1 is accelerated by operating one of the plurality of handles 5, the noise component has an inertial force due to the mass and acceleration of the handle 5 on the handle 5 that is not gripped. It is generated in the biaxial force sensor by its inertial force.

  The present invention is not limited to the configurations shown in the first, second, and third embodiments, and various modifications can be made. For example, the configurations of the above-described embodiments can be combined with each other.

1 Power Assisted Car (Car)
2 Car body 3 Drive wheel 4 Drive unit 5 Handle 5a Touch sensor 6 Control unit

Claims (9)

A power assisted transport vehicle,
A vehicle body, a drive wheel that linearly moves and turns the vehicle body, a drive unit that drives the drive wheel, a handle for operation, and two axes that detect an external force applied to the handle with at least two axial components A force sensor, and a control unit that performs power assist control so that the drive unit generates an assist force for linear movement or turning movement according to an external force detected by the biaxial force sensor,
The handle is provided with a power assist, wherein the handle is provided so that an operator's operation position is diagonally forward or diagonally behind the vehicle body.   2. The power control is performed according to claim 1, wherein the control unit cancels a turning moment caused by the fact that the handle is deviated from a center of the vehicle body among the external force applied to the handle, and performs power assist control. Power assisted transport vehicle.   The power steering transport vehicle according to claim 1 or 2, wherein the handle is provided on a front surface or a rear surface of the vehicle body.   The power steering transport vehicle according to claim 1 or 2, wherein the handle is provided on a side surface of the vehicle body.   The power steering transport vehicle according to claim 1, wherein the handle is provided on an upper surface of the vehicle body.   2. The power assisted transport vehicle according to claim 1, wherein the handle is provided on the left and right of the vehicle body.   The transport vehicle with power assist according to claim 6, wherein the control unit uses a sum of external forces applied to the left and right handles for power assist control. The handle includes a touch sensor that detects that the operator grips the handle,
3. The power-assisted transport vehicle according to claim 1, wherein the control unit performs power assist control using an external force applied to a handle whose grip is detected by the touch sensor as an effective external force. 4. . The handle is provided on the front and rear of the vehicle body,
The control unit validates an external force applied to only one of the front and rear handles, invalidates all external forces applied simultaneously to both the front and rear handles, or validates all external forces. 3. The power-assisted transport vehicle according to claim 1, wherein the power assist control is performed with only one of the front and rear external forces being effective. 4.

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