JP2011240422A - Robot hand and robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a robot hand which is highly versatile as a humanoid robot hand although it has a simple structure similar to a gripper-type robot hand.SOLUTION: Part of a belly at the tip of a finger is constituted of a separate member (fingertip member) where the fingertip member can be changed over between a posture housed in the finger and a posture protruding from the finger. In addition, a pressure sensor for detecting an object to be grasped is provided at the fingertip member whereby a large object or a heavy object can be tightly grasped by holding it on the belly of the finger with the fingertip member housed. A small object is grasped by the fingertip members with the fingertip members protruded. Since one pressure sensor works in either case, the structure can be simplified.

Description

The present invention relates to a robot hand capable of gripping an object and a robot including such a robot hand.

Due to recent advances in robot technology, many industrial robots have been used in industrial product manufacturing sites. For example, in an assembly line for industrial products, multiple industrial robots are installed along the line, and the robot automatically assembles various parts to the product being manufactured that flows on the line. Improvement is widely done. Or when transporting parts assembled by such robots to the line side,
It is also widely performed to improve production efficiency as a whole factory by conveying parts using a robot.

As described above, industrial robots used in assembly lines and the like basically have only two types of movements: an operation of grasping an object and an operation of releasing the grasped object. Since there are various shapes and sizes, it is not easy to grasp and release these objects in the same way. Therefore, it is usual to prepare a plurality of types (robot hands) where the robot grips the object in accordance with the shape and size of the object, and use different robot hands suitable for the object. Note that a robot hand that performs a simple operation of simply grabbing and releasing an object in this way is sometimes called a “gripper-type robot hand (or simply a gripper)”.

However, when using multiple types of robot hands, it is necessary to change the robot hand each time the shape or size of the object changes. During that time, the assembly line must be stopped, which reduces production efficiency. End up. Therefore, in order to be able to handle objects of different shapes and sizes with the same robot hand, a robot hand having five fingers imitating a human hand (hereinafter referred to as “humanoid” in this specification). Has been developed (referred to as Patent Document 1). In this humanoid robot hand, a plurality of movable parts corresponding to joints are provided on each of five fingers standing from a member corresponding to the palm, and by appropriately controlling these movable parts, It is possible to flexibly deal with objects having different shapes and sizes.

JP 2009-166152 A

However, the humanoid robot hand has a problem that the structure is complicated due to the large number of movable parts, leading to an increase in size and weight of the robot hand. The increase in size and weight of the robot hand causes the following problems when viewed as a whole robot. That is, when the size of the robot hand is increased, workability such as attaching parts to a narrow portion is greatly impaired. Further, the increase in the weight of the robot hand causes an increase in energy required to move this part. In particular, from the viewpoint of shortening the cycle time and improving production efficiency, the robot hand needs to be moved at a high speed, so when the weight increases, a large amount of energy is consumed to move the robot at a high speed. There is a problem of causing a decrease in energy efficiency.

The present invention has been made in order to solve at least one of the above-mentioned problems of the prior art, and is as simple as a gripper type robot hand, but is as high as a humanoid robot hand. An object is to provide a robot including a robot hand having versatility.

In order to solve at least a part of the problems described above, the robot hand of the present invention employs the following configuration. That is,
A robot hand that performs an operation of gripping an object using a plurality of fingers,
In the abdomen on the tip side of the finger,
Constituting a part of the outer surface of the abdomen, and a fingertip member formed in a bar shape;
A pressure sensor that is attached to the fingertip member and detects that the abdomen is in contact with the object; and
The fingertip member is provided to be switchable between a state protruding from the finger portion in the fingertip direction and a state accommodated in the finger portion,
The finger portion grasps the object with the abdomen of the finger portion when the fingertip member is housed, and grasps the object with the protruding fingertip member when the fingertip member protrudes. This is the gist.

In the robot hand of the present invention having such a configuration, a part of the abdomen on the tip side of the finger part (surface part on the side facing the other finger part) is constituted by a fingertip member, The state can be switched between a state in which the finger is stored and a state in which the finger protrudes from the finger.
And in a state where the fingertip member is stored, it is possible to hold the object with the abdomen of the finger part including the fingertip member, and in a state where the fingertip member protrudes, it is possible to hold the object with the protruding fingertip member. It has become. The shape of the fingertip member may be any shape as long as it is a so-called stick shape.

In this way, for an object that must be gripped with a strong force, such as a large object or a heavy object, the rigidity of the entire finger part can be increased by gripping the object with the fingertip member stored in the finger part. It can be used to hold the object firmly with a strong force. In addition, when gripping a small object, it is possible to easily pick up even small objects arranged in a narrow place by protruding the fingertip member from the finger part and holding it with the fingertip member. However, the object can be easily attached. In addition, the structure in which the fingertip member is accommodated in the finger part or protruded from the finger part can be realized with a very simple structure. Therefore, while having a structure as simple as that of a so-called gripper type robot hand, high versatility can be imparted like a so-called human type robot hand. Furthermore, the object can be detected by the pressure sensor provided on the fingertip member in the state where the fingertip member is stored in the finger part or in the state where the fingertip member is protruded. The pressure sensor for detecting the object may be one. For this reason, the structure of the robot hand can be simplified.

In such a robot hand of the present invention, the fingertip member is provided so as to be slidable in the fingertip direction with respect to the finger portion, and when the fingertip member is housed in the finger portion, the fingertip member is disposed on the outer surface of the abdomen. You may make it provide a pressure sensor in the location which comprises.

In this way, even when the fingertip member is stored in the finger portion or when the fingertip member protrudes from the finger portion, the object is detected by the pressure sensor provided on the fingertip member. Therefore, the structure of the robot hand can be simplified.

Further, in such a robot hand of the present invention, the fingertip member is stored in the finger portion by rotating from the state in which the fingertip member protrudes from the finger portion so that the base end portion of the fingertip member is folded as a fulcrum. Anyway. In this case, when the fingertip member is stored in the finger portion, the pressure sensor is provided in a range from the position where the fingertip member constitutes the outer surface on the ventral side of the finger portion to the back side of the fingertip member. May be.

In this way, even when the fingertip member is stored in the finger portion or when the fingertip member protrudes from the finger portion, the object is detected by the pressure sensor provided on the fingertip member. Therefore, the structure of the robot hand can be simplified.

Alternatively, in the robot hand of the present invention in which the fingertip member is accommodated in the finger portion by being rotated so that the base end portion of the fingertip member is folded as a fulcrum as described above, the following may be performed. First, a pressure sensor is provided at a location where a fingertip member protruding from a finger grips an object. Further, when the fingertip member is stored in the finger portion, the pressure sensor provided on the fingertip member is in contact with the surface of the finger portion. Then, when the finger part grips the target object, the finger part is detected to be in contact with the target object by detecting the force that the fingertip member is pressed against the contacted part of the finger part by the reaction force from the target object. You may do it.

Even if it does in this way, in either the state where the fingertip member is housed in the finger portion or the state where the fingertip member protrudes from the finger portion, the object is grasped by the pressure sensor provided on the fingertip member. Since an object can be detected, the structure of the robot hand can be simplified. Further, in the state in which the fingertip member is stored, the pressure sensor does not directly contact the object to be grasped, so that it is possible to avoid the pressure sensor from being damaged by the object.

In addition, the robot hands of the present invention described above all have a very simple structure and can be easily reduced in size and weight. Therefore, if a robot is constructed using these robot hands of the present invention, a small and high-performance robot can be constructed.

It is explanatory drawing which shows the structure of the robot hand of 1st Example. It is explanatory drawing which shows a mode that the robot hand of 1st Example grips a target object. It is explanatory drawing which shows a mode that the robot hand of 1st Example projects a fingertip member. It is explanatory drawing which shows a mode that the robot hand of 2nd Example projects a fingertip member. It is explanatory drawing which shows the structure of the fingertip part of the robot hand of 2nd Example. It is explanatory drawing which shows the structure of the fingertip part of the robot hand of the modification of 2nd Example. It is explanatory drawing which shows the other aspect of the fingertip part of the robot hand of the modification of 2nd Example. It is explanatory drawing which shows the robot provided with the robot hand.

A. First Example:
FIG. 1 is an explanatory diagram showing the configuration of the robot hand 10 of the first embodiment. As shown in the figure, the robot hand 10 of the first embodiment is composed of a palm portion 100 which is a substantially rectangular plate-shaped member, two finger portions 110 facing each other, and the like. These two fingers 110 are
Roughly, two members 112 and 114 are connected by a joint, and one member 11 is connected.
The other end side of 2 is connected to the palm 100 by a joint. Further, a fingertip member 116 having a substantially square bar shape is provided on the abdomen side (the side facing the other finger portion) of the distal end side member 114 so as to be slidable in the fingertip direction. Further, a pressure sensor 118 for detecting that the object W has been touched is attached to the surface of the fingertip member 116.

As shown in FIG. 1A, the fingertip member 116 is integrated with the member 114 and faces the abdomen of the finger portion 110 (other finger portions) when not protruding in the fingertip direction (stored state). Side surface portion). Therefore, in a state where the fingertip member 116 is stored, the object W can be gripped by being sandwiched by the abdomen of the finger part 110 while detecting the object W with the pressure sensor 118 attached to the fingertip member 116. Further, as shown in FIG. 1B, in a state where the fingertip member 116 is projected in the fingertip direction, the object W is gripped by being sandwiched by the fingertip member 116 while the object W is detected by the pressure sensor 118. It is possible.

FIG. 2 is an explanatory diagram showing a state in which the object W is gripped using the robot hand 10 of the first embodiment. FIG. 2A shows a state where a large object W (or a heavy object W) is gripped, and FIG. 2B shows a state where a small object W is gripped. . When gripping a large object W (or a heavy object W), as shown in FIG.
The fingertip member 116 is housed in the member 114. In this way, since the fingertip member 116 and the member 114 are integrated, sufficient rigidity can be ensured, so that even a heavy object W can be firmly grasped.

Further, when gripping a small object W, as shown in FIG.
6 is in a state of protruding from the member 114. Since the object W can be gripped by the fingertip member 116, for example, it is possible to easily perform an operation of picking up a small part from a confined part and attaching the part to the constricted part.

FIG. 3 is an explanatory diagram showing the positional relationship between the member 114 and the fingertip member 116 by enlarging the tip portion of the finger portion 110 of the first embodiment. On the left side of FIG.
14 shows a state in which the fingertip member 116 protrudes from the member 114 on the right side of the drawing. As shown in the figure, when the fingertip member 116 is housed, the surface of the fingertip member 116 is almost flush with the surface of the member 114, and the pressure sensor 118 attached to the surface of the fingertip member 116 is moved from the surface of the member 114. It is in a slightly protruding state. For this reason, as shown in FIG. 2A, in a state where the fingertip member 116 is housed, the member 114 and the fingertip member 116 integrally hold the object W and also hold the object W. This (or gripping force) can be detected by the pressure sensor 118 provided on the surface of the fingertip member 116.

Further, the fingertip member 116 is provided so as to be slidable in the fingertip direction with respect to the member 114 in the first embodiment, and the fingertip member 116 can protrude from the member 114 as shown on the right side of FIG. it can. For this reason, as shown in FIG. 2B, the small object W can be gripped by the protruding fingertip member 116, and the object W is held by the pressure sensor 118 provided on the surface of the fingertip member 116. It is possible to detect gripping (or gripping force).

Thus, in the robot hand 10 of the first embodiment, it is possible to switch between the state in which the fingertip member 116 is housed at the tip of the finger part 110 and the state in which the fingertip member 116 is protruded. It is possible to flexibly deal with the weighted object W. Moreover, as shown in FIG. 3, the structure of the fingertip member 116 and the member 114 can also be made very simple. For example, in the simplest case, a structure in which a human manually pulls out and stores the fingertip member 116 can be employed. Alternatively, when the tip of the finger part 110 is pressed against something, the fingertip member 116 protrudes, and when the tip of the fingertip member 116 is pressed against something and the fingertip member 116 is pushed in, the fingertip member 116 is stored. It is good also as what is called a toggle structure. Of course, even when an actuator for sliding the fingertip member 116 is provided, it can be realized with a simple structure because it is simply slid. For this reason, while being able to respond flexibly to various objects W, it can have a very simple structure like a so-called gripper type robot hand.

In addition, as shown in FIG. 2A, even when the object W is gripped in a state where the fingertip member 116 is stored, or the fingertip member 116 is protruded as shown in FIG. Even when the object W is gripped, the object W can be detected by the pressure sensor 118 provided on the fingertip member 116. For this reason, any kind of object W can be gripped by the pressure sensor 118 provided at one place.
It is possible to keep the 0 structure simple.

B. Second embodiment:
The robot hand 10 of the first embodiment described above has been described as being in a state where the fingertip member 116 protrudes from the member 114 constituting the distal end portion of the finger portion 110 by sliding. However, the structure in which the fingertip member 116 protrudes is not limited to the structure in which the fingertip member 116 is slid, and may be a structure in which the fingertip member 116 protrudes by rotating the tip of the fingertip member 116 as a fulcrum. Below, the robot hand 10 of such 2nd Example is demonstrated.

FIG. 4 is an explanatory view illustrating a structure in which the robot hand 10 of the second embodiment projects or stores the fingertip member 116. As shown in FIG. 4 (a), the fingertip member 116 of the second embodiment is accommodated in the member 114 in a state where the distal end side (the portion indicated as “A” in the drawing) is pivotally supported. . And as shown in FIG.4 (b), the fingertip member 1 makes a location of "A" a fulcrum.
When the finger 16 is rotated, the fingertip member 116 is in contact with the fingertip member 116 in the groove of the member 114.
6 is positioned. As a result, as shown in FIG.
It will be in the state which protruded from 4. Further, when the fingertip member 116 is rotated in the reverse direction with the position “A” as a fulcrum from the state in which the fingertip member 116 protrudes, the state shown in FIG. 4B is shown through the state shown in FIG. As described above, the fingertip member 116 is housed in the member 114.

FIG. 5 is an explanatory diagram showing the positional relationship between the member 114 and the fingertip member 116 by enlarging the tip portion of the finger part 110 of the second embodiment. On the left side of FIG.
14 shows a state in which the fingertip member 116 protrudes from the member 114 on the right side of the drawing. As shown in the figure, the fingertip member 116 is also used in the second embodiment.
In the state where the fingertip member 116 is housed, the surface of the fingertip member 116 is almost in a surface position with the surface of the member 114, and the pressure sensor 118 attached to the surface of the fingertip member 116 slightly protrudes from the surface of the member 114. . For this reason, the fingertip member 116 is the same as in the first embodiment described above.
In the state where the member is stored, the member 114 and the fingertip member 116 integrally hold the object W, and that the object W is held (or grasping force) is provided on the surface of the fingertip member 116. It is possible to detect with the pressure sensor 118.

In the second embodiment, the pressure sensor 118 is attached to the back side of the fingertip member 116 via the side surface of the fingertip member 116. Further, the member 1 for storing the fingertip member 116
A recess for escaping the pressure sensor 118 is formed in the groove on the 14 side. For this reason,
In a state where the fingertip member 116 is housed, the pressure sensor 118 is used only when the object W is gripped.
Since the pressure can be detected, it is possible to appropriately detect that the object W is gripped (or gripping force).

In addition, when the fingertip member 116 is rotated and protruded, the portion of the pressure sensor 118 that is on the back side of the fingertip member 116 in the state in which the fingertip member 116 is housed comes to the abdomen side of the fingertip member 116. The object W can be detected. For this reason, also in the second embodiment, the object W can be detected by the single pressure sensor 118 even when the fingertip member 116 is housed or the fingertip member 116 is protruded. As a result, the structure of the robot hand 10 can be simplified.

Also in the second embodiment, the structure of the fingertip member 116 and the member 114 can be made very simple. That is, most simply, a structure in which a fingertip member 116 is manually rotated by a human so that the fingertip member 116 protrudes or is housed can be employed. Of course, even when an actuator for rotating the fingertip member 116 is provided, it can be realized with a simple structure because it is simply rotated. For this reason, it is possible to flexibly cope with various objects W by switching between a state in which the fingertip member 116 is protruded and a state in which the fingertip member 116 is stored, and an extremely simple structure like a so-called gripper type robot hand. can do.

In the above description, the pressure sensor 118 is provided so as to be wound around the back side of the fingertip member 116 so that the object W can be detected even when the fingertip member 116 is protruded. However, with the fingertip member 116 protruding, the fingertip member 116
It is also possible to adopt a structure in which the pressure sensor 118 is provided only on the ventral side of the.

FIG. 6 is an explanatory view showing an enlarged structure of the fingertip member 116 and the member 114 according to a modification of the second embodiment. The left side of the figure shows a state where the fingertip member 116 is housed in the member 114, and the right side of the figure shows a state where the fingertip member 116 protrudes from the member 114. As shown on the right side in the drawing, in a state where the fingertip member 116 is protruded, the pressure sensor 118 is provided only on the ventral side portion of the fingertip member 116. Further, in the groove of the member 114 in which the fingertip member 116 is accommodated, a small convex portion 115 formed of an elastic member such as rubber or resin is provided. When the fingertip member 116 is rotated and stored in the member 114, the fingertip member 11
The pressure sensor 118 provided on the abdominal side 6 is lightly in contact with the convex 115 in the groove. Furthermore, as shown on the left side of FIG. 6, in a state where the fingertip member 116 is housed, the surface of the fingertip member 116 on the back side (the side where the pressure sensor 118 is not provided) is almost flush with the surface of the member 114. Become. For this reason, when the object W is gripped in a state where the fingertip member 116 is stored, the pressure sensor 118 of the fingertip member 116 is pressed against the convex portion 115 by the reaction force from the object W. As a result, since the output of the pressure sensor 118 increases, the object W can be detected by detecting this increase in output.

In this way, it is not necessary to provide the pressure sensor 118 so as to be wound up to the back surface side of the fingertip member 116, so that a small pressure sensor 118 can be used. as a result,
The manufacturing cost of the robot hand 10 can be suppressed. Further, when a large object W or a heavy object W is gripped, the fingertip member 116 is gripped and the convex part 115 directly contacts the pressure sensor 118. There is no direct contact with the object W. Therefore, even when the object W is gripped with a strong force, the pressure sensor 11
The advantage that 8 is hard to be damaged can be obtained. Further, when gripping a small object W, the fingertip member 116 is protruded so that the pressure sensor 118 is in direct contact with the object W, so that the object W is gripped (or gripped). It is possible to accurately detect the magnitude of the force.

In the modification of the second embodiment described above, the back side of the fingertip member 116 (pressure sensor 118).
You may make it provide a small convex part in the side which is not provided. FIG. 7 shows such a second
It is explanatory drawing which illustrated the other aspect of the modification of an Example. As shown in the drawing, if a small convex portion 117 is provided on the back side of the fingertip member 116, the convex portion 117 always protrudes from the member 114 even when the fingertip member 116 is accommodated in the member 114. For this reason, the fingertip member 11
When the object W is gripped in the state where the object 6 is accommodated, the reaction force from the object W is surely generated by the fingertip member 1.
16 and can be detected by the pressure sensor 118.

Although the robot hands of various embodiments have been described above, the present invention is not limited to all the embodiments and modifications described above, and can be implemented in various modes without departing from the scope of the invention.

For example, the robot hands of the various embodiments and modifications described above are very simple in structure, and thus can be easily reduced in size and weight. Therefore, as shown in FIG. 8, if these robot hands are attached to the tip of the robot arm 12 to configure the robot 500, the robot 500 can cope with various objects W, but is small and lightweight. In addition, even if the cycle time is shortened, it is possible to obtain a high-performance robot 500 in which the energy efficiency is hardly lowered.

10 ... Robot hand, 12 ... Robot arm, 100 ... Palm part,
110 ... finger, 112 ... member, 114 ... member,
115 ... Convex part, 116 ... Fingertip member, 117 ... Convex part,
118 ... Pressure sensor, 216 ... Fingertip member, 500 ... Robot,
W ... Object

Claims (5)

A robot hand that performs an operation of gripping an object using a plurality of fingers,
In the abdomen on the tip side of the finger,
Constituting a part of the outer surface of the abdomen, and a fingertip member formed in a bar shape;
A pressure sensor that is attached to the fingertip member and detects that the abdomen is in contact with the object; and
The fingertip member is provided to be switchable between a state protruding from the finger portion in the fingertip direction and a state accommodated in the finger portion,
The finger portion grasps the object with the abdomen of the finger portion when the fingertip member is housed, and grasps the object with the protruding fingertip member when the fingertip member protrudes. Robot hand. The robot hand according to claim 1,
The fingertip member is provided to be slidable in the fingertip direction with respect to the finger portion,
The pressure sensor is a robot hand provided at a location constituting an outer surface of the abdomen in a state where the fingertip member is housed in the finger. The robot hand according to claim 1,
The fingertip member is a member that is housed in the finger portion by rotating from the state protruding from the finger portion so as to be folded with the base end portion of the fingertip member as a fulcrum,
The said pressure sensor is a robot hand provided in the range from the location which comprises the outer surface of the said abdominal part in the state in which the said fingertip member was accommodated in the said finger part to the back side of this abdominal part. The robot hand according to claim 1,
The fingertip member is a member that is housed in the finger portion by rotating so as to be folded with the base end portion of the fingertip member as a fulcrum from a state protruding from the finger portion,
The pressure sensor is
The fingertip member protruding from the finger portion is provided at a location that comes into contact with the object when gripping the object,
When the fingertip member is housed in the finger portion, the fingertip member comes into contact with the surface of the finger portion, and when the finger portion grips the object, the fingertip member is caused to react by the reaction force from the object. A robot hand, which is a sensor that detects that the abdomen of the finger is in contact with the object by detecting a force pressed against the object.   A robot comprising the robot hand according to any one of claims 1 to 4.

Images