JP2019079251A - Autonomous moving body - Google Patents

Abstract

To provide an autonomous moving body that prevents a grip part and an arm from being sensed by an external sensor.SOLUTION: An autonomous moving body includes: a main body 11 that includes an omnidirectional wagon 11a; a grip part 12 that is coupled to the main body via an arm 12a which is coupled to the front portion of the main body 11 and which has a degree of freedom only in the height direction of the main body 11; a head part 13 provided so as to be rotatable relative to the main body 11; an external sensor 14 provided so as to be able to sense the forward side of a head part 13; and a control unit 15 that controls the operations of the respective parts. The autonomous moving body is subjected to an autonomous movement control on the basis of the sensing result from the external sensor 14. The control unit 15 offsets the direction of the main body 11 by a predetermined angle relative to a direction in which the external sensor 14 senses in such a way that the grip part 12 and the arm 12a become out of a sensing range of the external sensor 14 in the autonomous movement control.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an autonomous mobile body.

  In recent years, an autonomous mobile unit operating on a mobile route is known, which automatically determines a moving route by sensing information of the outside world.

  Conventionally, there exists Unexamined-Japanese-Patent No. 2016-074053 as a technique of such a field. The autonomous mobile body described in this publication includes: a main body having an omnidirectional carriage; a grip connected to the front of the main body via an arm having a degree of freedom only in the height direction of the main body; And a control unit configured to control movement of each of the elements.

JP, 2016-074053, A

However, the conventional autonomous mobile body described above may reduce the degree of freedom of the arm for cost reduction, and in this case, the arm can not be moved in the left-right direction of the carriage. When an autonomous mobile body is provided with an external sensor in front of the head and uses the sensing results of the external sensor, the height of the arm is lowered so that the arm is not reflected in the external sensor and interferes with sensing. Although it is conceivable that the arm can not be lowered sufficiently, the interference with sensing may not be eliminated.
SUMMARY OF THE INVENTION The present invention provides an autonomous mobile unit which does not interfere with sensing even if an arm having a degree of freedom only in the height direction is set in front of the main body, and does not interfere with sensing.

An autonomous mobile body according to the present invention comprises: a main body having an omnidirectional cart; and a grip portion connected to the front of the main body via an arm having a degree of freedom only in the height direction of the main body. And a head provided rotatably relative to the main body, an external sensor provided to be able to sense the front of the head, and a control unit for controlling the operation of each part, It is an autonomous mobile controlled by autonomous movement control based on a sensing result from an external sensor, and in the autonomous movement control, the controller senses the external sensor so that the arm is out of the sensing range of the external sensor. The orientation of the body is offset by a predetermined angle with respect to the
Thereby, the direction of the arm can be made to have an angular offset with respect to the traveling direction.

  As a result, it is possible to provide an autonomously moving body that does not interfere with sensing because the grip portion and the arm do not get reflected by the external sensor.

It is a perspective view of an autonomous mobile. It is the figure which showed the autonomous mobile which is drive | working in the state which direction of a main body and a head is the same. It is the figure which showed the autonomous mobile which is drive | working in the state which the main body and the head turned to a different direction. It is a figure which shows an example of the image acquired with an external sensor. It is the figure which looked at an autonomous mobile body from the upper direction. It is a figure which shows the right end angle and left end angle of a camera. It is a figure which shows the state which remove | eliminated the holding | grip object out of view using an offset angle. It is a figure which shows the state which detected the holding | grip object by the optical flow. It is a figure which shows the state which detected the holding | grip object from distance information. It is the figure which showed the state of the autonomous mobile body at the time of tracking a path | route.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the autonomous mobile body 1 is pivotable relative to the main body 11 having the omnidirectional cart 11 a, the grip portion 12 connected to the main body 11 via the arm 12 a, and the main body 11 The operation of each component of the head 13 provided, the external sensor 14 provided in front of the head 13, the carriage provided on the main body 11, the grip 12, the head 13 and the external sensor 14 is controlled A control unit 15, an offset calculation unit 16, a route calculation unit 17, and a route following calculation unit 18 are provided. The autonomous mobile body 1 autonomously moves by performing autonomous movement control according to the sensing result by the external sensor 14. The control unit 15, the offset calculation unit 16, the path calculation unit 17, and the path tracking calculation unit 18 are not shown in FIG. 1 because they are provided in the main body 11.

  The main body 11 is, for example, a column whose bottom is in the vertical direction. Under the main body 11, an omnidirectional cart 11a is provided. Moreover, the head 13 is connected to the upper part of the main body 11. Further, for example, inside the main body 11, a control unit 15, an offset calculation unit 16, a route calculation unit 17, and a route following calculation unit 18 are provided. The main body 11 also includes a power source such as a motor for driving the omnidirectional cart 11 a, the arm 12 a, and the grip 12, and power is given according to the control of the control unit 15. One end of an arm 12 a is connected to the front side of the main body 11, that is, the front direction (the front direction of the main body).

  The omnidirectional cart 11a is a cart on which the main body 11 is mounted, and a plurality of wheels are provided on the lower surface. The omnidirectional cart 11 a can operate the autonomous mobile body 1 in any direction by operating according to the control of the control unit 15. For example, as shown in FIG. 2, the omnidirectional cart 11a travels not only in the front direction when the main body 11 and the head 13 face in the same direction, but also as shown in FIG. Even when the head 13 faces in different directions, the autonomous mobile body 1 can be moved not in the front direction of the main body 11 but in the front direction of the head 13.

  The grip 12 is a gripper that is provided at the tip of the arm 12 a and grips an object. The gripping unit 12 brings the article into the gripping state or releases the gripping state according to the control of the control unit 15.

  One end of the arm 12a is connected to the front side of the main body 11, and the grip 12 is connected to the other end. For example, the arm 12a has a degree of freedom only in the height direction. Arm 12a may have a plurality of joints, and may be operable with multiple degrees of freedom such as five degrees of freedom according to a control signal from control unit 15.

  An external sensor 14 that senses the front direction of the head 13 is disposed on the front side of the front side of the head 13. The head 13 is operable independently of the main body 11. That is, the front direction (head front direction) sensed by the external sensor 14 provided on the head 13 and the main body front direction can not be in agreement.

  The external sensor 14 is a sensor for detecting an obstacle in the head front direction, and for example, a camera for capturing an image or a 3D sensor can be used. FIG. 4 is an example of a case where a camera is used as the external sensor 14. FIG. 4 shows a state in which the object to be grasped and the grasping portion 12 are reflected in the field of view of the external sensor 14. A sensor that can be used for the external sensor 14 is not limited to a camera or a 3D sensor.

  The control unit 15 controls the operations of the omnidirectional cart 11 a, the gripping unit 12, and the head 13 according to the information of the external world sensed by the external world sensor 14. The control unit 15, the offset calculation unit 16, the route calculation unit 17, and the route following calculation unit 18 are, for example, a computer such as a memory incorporated in the main body 11, a CPU (central processing unit), and a storage device storing a route map. It may be realized by

  The offset calculation unit 16 calculates an angular offset of the arm 12 a and the external sensor 14. In other words, the offset calculation unit 16 calculates an offset angle of the head 13 with respect to the main body 11 in which the grip 12 does not appear in the sensing area during sensing by the external sensor 14 provided on the head 13 . For example, the direction of the head 13 and the direction of the external sensor 14 are synchronized, and the directions of the main body 11, the omnidirectional cart 11a, and the arm 12a operate in synchronization, so that the offset angle of the head 13 with respect to the main body 11 is determined. The offset angles of the external sensor 14 and the arm 12a are also uniquely determined.

  The route calculation unit 17 calculates a route for going to the goal based on the map stored in the storage device and the sensor information acquired by the external sensor 14. The calculation method is not limited.

  The path following calculation unit 18 calculates the speed that the robot should output from the offset angle obtained by the offset calculation unit 16, the route obtained by the path calculation unit 17, and the current position of the autonomous mobile body 1. Performs route tracking control.

  Here, a calculation example by the offset calculation unit 16 is shown. First, an operation example of the offset calculation unit 16 in the case where the position and size of the object to be grasped are known will be described. Here, FIG. 5 shows the field of view of the camera used as the external sensor 14 in the case where the autonomous mobile body is viewed from above.

  First, since the position and size of the object to be grasped are known, as shown in FIG. 6, it is possible to calculate angles with respect to the optical axis of the camera with respect to the right end and left end of the object to be grasped.

Next, the offset calculation unit 16
Offset angle = field angle / 2−end angle is calculated, and the one with the smaller absolute value at the right end and the left end is adopted as the offset angle.

  Thus, as shown in FIG. 7, by rotating the main body 11 using the offset angle, it is possible to adjust so that the object to be grasped does not appear in the field of view of the external sensor 14. In other words, the orientation of the main body 11 can be offset by a predetermined angle with respect to the sensing direction of the external sensor 14 so that the grip 12 and the arm 12 a are out of the sensing range of the external sensor 14.

  Next, an operation example of the offset calculation unit 16 in the case where the position and the size of the object to be grasped are unknown and a camera is used as the external sensor 14 will be described.

  First, the head 13 and the main body 11 are operated so as to be relatively reverse to each other. For example, when viewed from above, the head 13 is operated clockwise, and the main body 11 including the omnidirectional cart 11a is operated counterclockwise.

  At this time, since the holding unit 12 and the object to be held move according to the rotation of the omnidirectional cart 11a, as shown in FIG. 8, the offset calculating unit 16 detects the optical flow of the image acquired by the camera which is the outside sensor 14. By performing the calculation, the area of the object to be grasped is detected.

  After that, the control unit 15 moves the object to be grasped outside the angle of view of the external sensor by moving the omnidirectional cart 11a until the area of the object to be grasped calculated by the offset calculation unit 16 is outside the angle of view of the camera. Let In addition, the difference between the angle of the external sensor 14 and the omnidirectional cart 11a at that time, that is, the angle between the main body front direction and the head front direction can be adopted as the offset angle.

  Therefore, the orientation of the main body 11 can be offset by a predetermined angle with respect to the sensing direction of the external sensor 14 so that the grip 12 and the arm 12 a are out of the sensing range of the external sensor 14.

  Next, an operation example of the offset calculation unit 16 in the case where the position and size of the object to be grasped are unknown and the 3D sensor is used as the external sensor 14 will be described.

  First, sensing is performed by the external sensor 14 which is a 3D sensor. Then, as shown in FIG. 9, it is considered that all objects closer than the predetermined distance are objects to be grasped, and an area to be focused is determined.

Thereafter, the right end and the left end of this area are regarded as the right end and the left end of the object to be grasped, and the angles with respect to the front direction of the external sensor 14 with respect to the right end and the left end of the object are calculated. That is, the offset calculation unit 16
Offset angle = field angle / 2−end angle is calculated, and the one with the smaller absolute value at the right end and the left end is adopted as the offset angle.

  As a result, as in the case where the position and size of the object to be grasped are known, the direction in which the external sensor 14 senses such that the grasping portion 12 and the arm 12a are out of the sensing range of the external sensor 14 The orientation can be offset by a predetermined angle.

  Next, an operation of control for maintaining the offset angle of the arm 12a and the external sensor 14 while following the path using the calculation by the path following calculation unit 18 will be described using FIG.

  The route following calculation unit 18 searches for a route point closest to the current position of the autonomous mobile body 1 on the given route (step S1).

  The route following calculation unit 18 calculates the velocity (Vx, Vy) from the velocity V required of the autonomous mobile body 1 in the direction (ψ) along the route of the searched route point (step S2). For example, the velocity is Vx = Vcosψ, Vy = Vsinψ.

  The path following calculation unit 18 adds the speed to return to the path point from the distance (d) between the path point and the autonomous mobile body 1 (step S3). For example, Vx = Vcosx + Pt * d * sinψ, and Vx = Vsinψ-Pt * d * sinψ. Pt is a gain arbitrarily determined.

  The path following calculation unit 18 sets Vω = Pω * (α + θ−β) from the direction α of the external sensor 14, the direction β of the arm 12a, and the offset angle θ, and performs feedback control while satisfying the offset angle θ. The rotation speed Vω of the robot is calculated (step S4). Here, Pω is an arbitrarily determined gain.

  The path following calculation unit 18 performs calculation to convert the velocity (Vx, Vy, Vω) into the carriage coordinate system, that is, the velocity (vx, vy, vω) based on the front direction of the main body with the arm 12a attached (step S5).

  In addition, the path following calculation unit 18 performs calculation to convert the calculated velocity (vx, vy, vω) so that the velocity and acceleration do not exceed predetermined limit values, and (vx ', vy', vω ' ) Is calculated (step S6).

  The control unit 15 controls the operation of the omnidirectional cart 11a with the calculated velocity (vx ', vy', vω ') as the target velocity, and causes the autonomous mobile body 1 to travel (step S7).

  As a result, the direction of the arm 12a can be made to have an angular offset with respect to the traveling direction, so that the autonomous mobile body does not show off the gripping portion 12 and the arm 12a on the external sensor 14, and interferes with sensing. It is possible to move without taking it.

  The present invention is not limited to the above embodiment, and can be appropriately modified without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 autonomous mobile body 11 main body 11a omnidirectional cart 12 grip part 12a arm 13 head 14 outside sensor 15 control part 16 offset calculation part 17 path calculation part 18 path following calculation part

Claims (1)

A body having an omnidirectional carriage,
A grip connected to the main body via an arm connected to the front of the main body and having a degree of freedom only in the height direction of the main body;
A head rotatably provided relative to the body;
An external sensor provided to be able to sense the front of the head;
A control unit that controls the operation of each unit;
An autonomous mobile body controlled autonomously based on the sensing result from the external sensor,
The control unit, in the autonomous movement control, offsets the direction of the main body by a predetermined angle with respect to the sensing direction of the external sensor so that the grip unit and the arm are separated from the sensing range of the external sensor. body.

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