JP2004230509A - Mobile robot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mobile robot comprising an articulated manipulator loaded on a mobile carriage, and not doing harm to a person and an article around it, especially while the articulated manipulator at the time of travelling or standing by is not in operation. <P>SOLUTION: The articulated manipulator 2 is arranged to be folded on an upper part of the mobile carriage 1, and a cover 3 for storage free to open and close so as to completely cover the articulated manipulator 2 in its folded position is set. Thus, safety measures against malfunction of the articulated manipulator on the mobile robot are carried out only with a mechanical part, and the measures simpler and more certain than the electrical safety measures are carried out. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a mobile robot in which a multi-joint manipulator is mounted on a mobile trolley having a traveling mechanism, and particularly to a safety measure against malfunction of the multi-joint manipulator.
[0002]
[Prior art]
As a safety measure against a malfunction or the like of a multi-joint manipulator in a conventional mobile robot having a multi-joint manipulator mounted on a movable cart, there are examples disclosed in Patent Literature 1, Patent Literature 2, Patent Literature 3, and the like.
[0003]
As disclosed in Patent Literature 1 or Patent Literature 2, for the purpose of preventing the articulated manipulator of the mobile robot from malfunctioning for some reason when not operating and damaging surrounding people or articles, A safety measure has been proposed in which a detector for detecting a fixed position of the multi-joint manipulator is installed, and when the multi-joint manipulator leaves the fixed position due to a malfunction, the operations of the multi-joint manipulator and the movable cart are stopped.
[0004]
Further, as disclosed in Patent Literature 3 or the like, a configuration is adopted in which the other three surfaces in the mobile robot except for one surface in the working direction of the multi-joint manipulator are surrounded by safety fences to limit the operation area of the multi-joint manipulator. Has also been proposed.
[0005]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2-303795 [Patent Document 2]
JP 2001-96487 A [Patent Document 3]
JP-A-6-155341
[Problems to be solved by the invention]
However, in the case of the safety device using the fixed position detector as described above, there are the following problems.
[0007]
First, if the detector malfunctions due to electrical detection, malfunction of the articulated manipulator cannot be detected, or conversely, the fixed position detector uses limit switches, photoelectric switches, etc. There is a problem that the mobile robot frequently stops due to erroneous detection due to vibration, disturbance light, or the like in the use environment.
[0008]
In addition, the actual shape of the articulated manipulator has a protruding shape with edges such as sheet metal, a tapered convex shape, and the like. There is also a problem that there is a risk of causing harm to the surrounding humans or articles in the case of contact with the surrounding humans or articles.
[0009]
In the case of a mechanism in which a safety fence is provided on three surfaces of the mobile trolley, the remaining one surface is fixedly opened as a work surface of the multi-joint manipulator, so that the multi-joint such as when the mobile robot is traveling or waiting. If the manipulator is not operated, the safety on the open side cannot be ensured. In addition, the fixed safety fence provided to ensure safety during work has a very large external dimension in order to secure the operating range of the articulated manipulator, and often becomes larger than the external shape of the mobile trolley. The safety fence itself may become a dangerous substance at the time of standby or at the time of standby.
[0010]
The present invention relates to a mobile robot having a multi-joint manipulator mounted on a movable trolley, particularly in a traveling or a standby state, in which the multi-joint manipulator does not harm the surrounding people and articles when the multi-joint manipulator is not operated. The purpose is to make safe measures possible.
[0011]
[Means for Solving the Problems]
In order to solve this problem, in the present invention, an articulated manipulator is disposed on a movable cart so as to be foldable, and an openable storage cover that can completely cover the articulated manipulator in a folded position is installed. Things.
[0012]
ADVANTAGE OF THE INVENTION According to this invention, the safety measures against the malfunction of the articulated manipulator in the mobile robot can be made only with the mechanical parts, the simpler and more reliable measures can be taken than the electric safety measures, and the role of protection of the articulated manipulator can be further improved. Can also fulfill. Further, by the arrangement of the articulated manipulator and the wheels according to the present invention, stable traveling performance and good steering performance of the mobile trolley and a wide operating range of the articulated manipulator can be simultaneously secured.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
According to the first aspect of the present invention, the multi-joint manipulator is foldably disposed on the movable cart, and an openable storage cover is provided to completely cover the multi-joint manipulator in the folded position. Therefore, even if the articulated manipulator malfunctions while the mobile robot is traveling or waiting, the operation of the articulated manipulator is restricted by the storage cover and the articulated manipulator is moved out of the storage cover. It has the effect that it is safe without being lost.
Further, it has an additional effect that an external force can be prevented from being directly applied to the articulated manipulator in the event of a collision or a fall.
[0014]
According to a second aspect of the present invention, the multi-joint manipulator is a vertical multi-joint type having two arms connected in series, and the first arm and the second arm are configured so that both arms can be folded at the upper part of the movable cart, In a completely folded state, both arms are in a substantially horizontal position on the ceiling surface of the trolley, and even in a completely folded state, the outer shapes of both arms do not protrude from the outer shape of the movable trolley. Thus, when the mobile robot travels, the position of the center of gravity of the entire mobile robot can be lowered, and the center of gravity of both arms can be set near the center of the mobile trolley, so that the mobile robot can travel stably. Further, the outer dimensions of the storage cover for storing the multi-joint manipulator in a folded posture can be made compact, and the mobile robot can be operated safely when traveling.
[0015]
According to a third aspect of the present invention, a pair of left and right drive wheels and at least one driven or driven wheel are provided at the rear of the bottom of the movable trolley, and the rotation center of the first arm of the articulated manipulator is set at the center of the movable trolley. By arranging it near the upper front, the gripping hand at the tip of the articulated manipulator can grasp an article placed on the floor immediately before the movable trolley, and the center of gravity position of the entire mobile robot can be determined regardless of the attitude of the articulated manipulator. It is intended to always be within the range of the inside of the polygon connecting the grounding points of the wheels of the movable trolley, whereby the ground pressure can be applied to the front drive wheels, slips and the like can be prevented, and stable running performance can be prevented. In addition, good steering performance can be obtained because the load moment on steering can be reduced, and the movable range of the mobile robot in the forward direction can be widened. It has the effect of.
[0016]
According to the fourth aspect of the present invention, the shape of the openable and closable storage cover is formed to be a shape that is outwardly convex and smoothly continuous, and the mobile robot and the surrounding human or article are in contact with each other. Also in this case, there is an effect that it is possible to prevent injuries at the projections and the like.
[0017]
According to a fifth aspect of the present invention, the opening / closing of the storage cover that can be opened and closed can be automatically performed by a command from the control device of the mobile robot using the actuator of the motor, and automatically in conjunction with the arm folding operation. The cover can be opened and closed, so that the articulated manipulator can be reliably and smoothly switched between the non-operation state and the operation state.
[0018]
1 to 3 show an embodiment of the present invention.
[0019]
(Embodiment 1)
FIG. 1 shows a side view and a front view of a mobile robot according to the present invention, and particularly shows a state where the mobile robot is traveling or waiting.
[0020]
In FIG. 1, reference numeral 1 denotes a mobile trolley, 2 denotes an articulated manipulator, 3 denotes a storage cover, and the articulated manipulator 2 is in a non-operating state and is folded at the upper part of the mobile trolley 1 and is indicated by a two-dot chain line. The storage cover 3 is closed and covers the entire articulated manipulator 2.
[0021]
The movable trolley 1 has driving wheels 101a and 101b on the front left and right sides of the bottom, caster-type driven wheels 102a on the rear left and right of the bottom, and 102b (not shown) on the rear side of 102a in FIG. The drive wheels 101a and 101b are connected to an actuator such as a motor via a speed reducer such as a gear (not shown), and can rotate independently in both clockwise and counterclockwise directions by rotating the actuator. The mobile trolley is steered by the rotational speed difference between the left and right actuators.
[0022]
That is, when the rotation speeds of the left and right actuators are the same, the vehicle goes straight forward or backward, and when there is a rotation speed difference, the steering is steered in the direction of the lower rotation speed. If so, make a turn. Control of each actuator is performed by commands from an actuator driving amplifier 104, a sub-control device 105 mainly for real-time control, and a main control device 106 for external interface and overall management. The rotation angle of the drive wheel 101 is detected by a rotation angle detector (not shown) and fed back to the control system.
[0023]
Further, each wheel is fixed to the movable trolley frame 103 via an elastic body such as a coil spring (not shown), so that the wheel surely comes into contact with the floor surface.
[0024]
In the above description, the steering based on the difference between the left and right rotational speeds has been described. However, the steering can be performed by changing the direction of the drive wheel or the driven wheel by the steering actuator. The number of driven wheels does not need to be two, and it is sufficient that at least one follower wheel is provided. Further, the driven wheel may be a driving wheel driven by any actuator.
[0025]
The articulated manipulator 2 is a 6-axis vertical articulated type having a first arm 207, a second arm 208, a distal arm 209, and an article gripping hand 210 fixed to an end of the distal arm 209 mechanically connected in series. Each arm is rotatably held on a first shaft 201, a second shaft 202, a third shaft 203, a fourth shaft 204, a fifth shaft 205, and a sixth shaft 206 by a bearing (not shown) or the like. An actuator such as a motor (not shown), a speed reducer such as a gear, a rotation angle detector, and the like are arranged on each shaft so that each arm can rotate and its rotation angle can be detected.
The article gripping hand 210 is configured such that the positions of the article gripping members 211a and 211b facing each other are interlocked by an actuator such as a motor and the like, so that the article to be gripped can be gripped by moving the article gripping members 211a and 211b. It has become. If necessary for driving each shaft, it is naturally possible to use a driving member such as a belt and a pulley.
[0026]
Each of the actuators is supplied from an actuator driving amplifier 104, a sub-control device 105 for mainly real-time control, and a main control device 106 for external interface and overall management as described in the description of the movable carriage 1. Controlled by command. As described in claim 2, both the first arm and the second arm can be folded after the upper part of the movable cart, and when both arms are completely folded, both arms are substantially horizontal to the ceiling surface of the cart. , And the outer shape of both arms does not protrude from the outer shape of the movable cart even in a completely folded state.
[0027]
In the above description, the example of the 6-axis vertical articulated type has been described. However, the number of axes may be at least two, that is, the second axis and the third axis, and conversely, the number of axes may be seven or more. is there. Although the driving method has been described using the configuration of the motor and the speed reducer, other driving methods such as hydraulic or pneumatic driving, driving with a shape memory alloy, driving with an artificial muscle, and the like are also possible.
[0028]
The storage cover 3 is composed of a fixed cover 301 and a movable cover 302. The fixed cover is fixed to the movable trolley 1 by a connecting member (not shown) at the upper rear of the movable trolley 1, and the movable cover 302 rotates at a fulcrum 303. It is kept possible. Further, the fulcrum 303 is provided with a cover opening / closing mechanism 304 including an actuator such as a motor (not shown), a speed reducer, and a limit switch for confirming opening / closing of the cover. The movable cover 302 is rotated around the fulcrum 303 by the cover opening / closing mechanism 304. It is driven dynamically. The cover opening / closing mechanism 304 is also controlled by the same control system as that of the movable trolley 1. While the mobile robot is running or waiting, the movable cover 302 is rotated by the cover opening / closing mechanism 304 in the counterclockwise direction in FIG. 1 around the fulcrum 303 to a position such that it covers the entire folded articulated manipulator 2. Move. When the work by the articulated manipulator 2 is started, the movable trolley 1 is first stopped at the work position, and after confirming that there is no obstacle around by a confirmation device (not shown), the movable cover 302 is supported by the cover opening / closing mechanism 304 to support the fulcrum 303 1 is rotated clockwise in FIG. 1 to a position where the articulated manipulator 2 does not interfere with the movable cover 302.
[0029]
In this state, the movable cover 302 is housed inside the fixed cover 301, and the multi-joint manipulator 2 moves from the space in front (left side in FIG. 1) where the movable cover 302 moves and becomes open. It becomes possible to move to the work space of the manipulator 2. The fixed cover 301 and the movable cover 302 are made of a material and a structure such that the articulated manipulator 2 is rotatably driven by the maximum driving force of each actuator and is not damaged even if both collide. The material of the fixed cover 301 and the movable cover 302 is desirably a metal material such as an aluminum sheet metal. However, as long as the above-mentioned strength can be satisfied, the whole or a part may be made of resin. The outer shapes of the fixed cover 301 and the movable cover 302 are outwardly convex and smoothly continuous curved surfaces as described in claim 4.
[0030]
Although the fixed position detector of the articulated manipulator 2 is not provided in the above description, it is of course possible to take a double safety measure by providing a fixed position detector. Further, the fixed cover 301 is not always necessary, and the same function can be achieved only by the movable cover 302.
[0031]
(Embodiment 2)
FIG. 2 shows a side view of the mobile robot according to the present invention, and particularly shows a state where the mobile robot is working by operating the articulated manipulator 2.
[0032]
2, the movable cover 302 is rotated clockwise by a cover opening / closing mechanism 304 and is in an open state. In this state, the articulated manipulator 2 can move to the front working space, and can work in the arm posture as shown in FIG. 2, for example.
[0033]
The arm posture shown in FIG. 2 is the arm posture when an article placed on the floor immediately before the movable trolley 1 is to be gripped by the article gripping hand 210 described in claim 3, and the articulated manipulator 2 The center of rotation of the first arm 207, that is, the second axis 202 of the articulated manipulator 2 is moved so that such an arm posture, that is, the tip of the second arm 208 can reach the floor immediately before the movable cart 1. It is arranged near the upper front of the cart 1.
[0034]
(Embodiment 3)
FIG. 3 shows a section AA in FIG.
[0035]
In FIG. 3, points A1 and A2 indicate the ground points of the driving wheels 101a and 101b and the floor, respectively, and points B1 and B2 indicate the driven wheels 102a and 102b and the ground points of the floor, respectively. In order for the mobile robot to travel and work stably without falling, the position G of the center of gravity of the entire mobile robot needs to be inside the square surrounded by the points A1, A2, B2 and B1. is there.
[0036]
In the present invention, the article gripping hand 210 grips the article having the maximum weight within the specification range while the first arm 207, the second arm 208, and the tip arm 209 extend horizontally in the forward direction of the movable cart, and Even in the worst posture of falling such as falling downhill with the maximum floor inclination angle forward, the center of gravity G of the entire mobile robot is located within the range inside the square.
[0037]
【The invention's effect】
As described above, according to the present invention, in a mobile robot equipped with a multi-joint manipulator of a movable trolley, when the multi-joint manipulator during traveling or standby is not operated, the contact between the multi-joint manipulator and the outside can be completely completed with a simple mechanism. This has the advantageous effect that safe and stable running performance, good steering performance and a wide forward operating range of the articulated manipulator can be simultaneously secured.
[Brief description of the drawings]
FIG. 1 is a side view and a front view showing a traveling or standby state of a mobile robot according to a first embodiment of the present invention. FIG. 2 is a diagram showing work performed by operating an articulated manipulator 2 according to a second embodiment of the present invention. FIG. 3 is a side view showing the mobile robot when the vehicle is moving. FIG. 3 is a sectional view showing the positions of wheels on the bottom of the mobile trolley 1 according to the third embodiment of the present invention.
DESCRIPTION OF SYMBOLS 1 Moving trolley 2 Articulated manipulator 3 Storage cover 101 Drive wheel 102 Follower wheel 103 Moving trolley frame 104 Actuator driving amplifier 105 Sub-control device 106 Main control device 207 First arm 208 Second arm 209 Tip arm 210 Hand for gripping articles 211 article gripping member 301 fixed cover 302 movable cover 303 fulcrum 304 cover opening and closing mechanism

Claims (5)

A mobile robot having a multi-joint manipulator foldably disposed on a movable trolley, and an openable storage cover capable of completely covering the multi-joint manipulator in a folded posture. The articulated manipulator is a vertical articulated type having two arms connected in series, and the first arm and the second arm are configured so that both arms can be folded at the upper part of the movable cart. 2. The movement according to claim 1, wherein the arms are in a posture substantially horizontal with respect to the ceiling surface of the cart, and the outer shapes of both arms do not protrude from the outer shape of the movable cart even when the arms are completely folded. robot. A pair of left and right drive wheels are provided at the front of the bottom of the movable trolley and at least one driven or driven wheel is provided at the rear of the bottom of the movable trolley, and the rotation center of the first arm of the articulated manipulator is arranged at a position near the upper front of the movable trolley. Thus, the article placed on the floor immediately before the mobile trolley can be gripped by the gripping hand at the tip of the multi-joint manipulator, and the center of gravity of the entire mobile robot always contacts the wheels of the mobile trolley regardless of the attitude of the multi-joint manipulator. The mobile robot according to claim 1, wherein the mobile robot is within a range inside a polygon connecting the points. The mobile robot according to claim 1, wherein the shape of the storage cover that can be opened and closed is a shape that is outwardly convex and smoothly continuous. The mobile robot according to claim 1, wherein the openable and closable storage cover can be automatically opened and closed by a command from a control device of the mobile robot using an actuator of a motor.

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