ES2416931B2 - GUIDED METHOD OF TELEOPERATED ROBOTIC DEVICES TO ALTERNATE CONTROL MODE IN POSITION AND SPEED CONTROL MODE - Google Patents

Abstract

Method of guiding teleoperated robotic devices to alternate control mode in position and control mode in speed, which includes the adaptation of the master device (1) by dividing its work area (6) into an internal region (7) where the mode is implemented control position of the slave robot (3), and external region (8) where the speed control mode is implemented; use of a communications network (4) to transmit movement orders and forces exerted by both devices; adaptation of the master device (1) to produce vibration effects in the transitions between internal (7) and external region (8), indicating the change from one control mode to another the change from one control mode to another occurs from This ensures the stable operation of the devices and the maximum teleproprioception for the operator.

Description

Guidance method for teleoperated robotic devices to toggle control mode in position and control mode in speed.

OBJECT OF THE INVENTION

The invention, as stated in the present specification, refers to a method of guiding teleoperated robotic devices to alternate control mode in position and control mode in speed, contributing to the function to which several advantages and characteristics of novelty, which will be described in detail below and which represent a notable improvement over systems currently known in the state of the art for the same purpose.

More in particular, the invention focuses on the development of an innovative guiding method with force reflection, being applicable to remote manipulation operations in which at least one robot that performs the operation in a remote environment, called a slave, participates , and a robot guidance device that manipulates an operator, called a master, and whose movements are used to guide the movements of the slave, allowing alternately use, control modes in position and modes of speed control of said slave with respect to the master . The change from one control mode to another has been defined in order to avoid instabilities in the transition between the two control modes, based on the adaptation of the master device to operate in two different regions, one for each mode, and providing haptic information to the operator when moving from one region to another.

The master device also reflects forces on the operator, which allows him to perform manipulation tasks with skill and changes in the control mode efficiently.

FIELD OF APPLICATION OF THE INVENTION

The field of application of the present invention is part of the technical sector of robotics and remote control of devices, including activities such as teleoperation or telerobotic, applications in which a person uses a device, known as a teacher, which allows guide the movement of another remote device, known as a slave.

BACKGROUND OF THE INVENTION

Currently, almost all of the robots or similar systems guided remotely use a single mode of control, which is usually either position control or speed control. When the operator uses a master device with dimensions similar to those of the slave, the position control is usually used. On the contrary, when the operator uses a dimensionally or dynamically different device than the remotely controlled one, the speed control is usually used.

A common example of speed control is the guidance of a crane. The crane represents the slave device, which is controlled by the operator by means of levers, which act as the master device. The activation of these levers are what determine the speed and direction of rotation of the different degrees of freedom of the crane. When the levers are activated, then the crane moves; that is, if the levers are not at their resting point, movement orders are generated for the crane. This type of guidance is called speed control.

Other devices such as ‘joysticks’ are also used as a master device. ‘Joysticks’ are commonly used as computer peripherals for the user to interact with different types of applications and computer games. Usually, the ‘joystick’ is used to indicate the direction of movement and / or speed that the user wants for the element that he controls in the application.

For its part, position guidance is characteristic of robotics applications in which it is desired that the remote controlled robot (slave) faithfully reproduce the movements performed by the operator through the use of a device (master). This type of guidance requires that master and slave have a certain kinematic relationship, or at least a similar field of work. This is the case of most of the telerrobots used in the industry; such as the Kraft Telerobotics Grips, Mascot IV of Oxford Technologies LTD., or the Titan telemanipulators of Schilling Robotics.

However, none of the telerobial systems currently marketed allows the combination of position control and speed control. When there are significant differences between the master and slave work field, the speed control or the position control with indexing is used. Indexing consists in decoupling master and slave when the master reaches his limit of movement, then the teacher is relocated to a new position that allows the slave to be guided again favorably. He

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The disadvantage of indexing is that the movement references between master and slave are lost. This means a decrease in system performance since the operator needs to relocate to the new reference system.

As is known, teleproprioception is known to the correct perception that a person who guides a robot has when he feels that the movements he performs are correctly reproduced by the robot he is guiding remotely. Teleproprioception is a problem related to the coherence between the reference systems of the movements that are performed. The reference systems involved are those linked to: master device, slave device, and information feedback devices.

The master and slave reference systems depend on the base to which each one is attached. The most common information feedback device is formed by one or several video cameras, and its reference system will depend on where the cameras that may have a fixed position are fixed, or on the contrary be in solidarity with the slave robot.

The great advantage of position control is that it guarantees high levels of teleproprioception and therefore high productivity of teleoperated systems. The problem of indexing is that coherence is lost between the master and slave reference systems, and with it teleproprioception, and as a consequence the productivity is significantly reduced.

The objective of the guidance method proposed by the present invention is, therefore, to avoid said inconveniences and maintain the operator's teleproprioception, even by varying the control mode, so as not to affect the productivity of the teleoperation system, it should be noted that, at less by the applicant, the existence of any other guiding method or invention of similar application that has similar technical characteristics to those presented here, according to the principles of the claims, is unknown.

EXPLANATION OF THE INVENTION

Specifically, what the invention proposes, as already noted above, is a method of guiding robots remotely in order to efficiently combine position control and speed control. The position control will be used when it is required to guide a robot very precisely and the speed control will be used when large displacements are required.

In robot guiding operations, the participation of two basic devices is considered, one the robot that performs the operation in a remote environment, known as a slave; and another, the device used to guide the slave, which is called the master. A human operator will be in charge of using the master device in order to guide the movements of the slave.

To carry out said guidance, the method advocated by the present invention is based on defining two different regions of work for the master device. Thus, an interior region is contemplated in which a position control mode is implemented, and an external region in which a speed motion control mode is implemented. And, to avoid possible instabilities in the control systems in the transitions between both control modes, the master device is adapted to work according to the following operating rules:

The control mode, in the region or internal zone of the master, will always start from the rest position of the slave robot. This control mode will be in position. That is to say, the movements of the master will correspond with similar movements of the slave, being able to reflect forces to the master that, usually, will correspond to the forces exerted by the slave on the environment.

When the teacher passes from the inner to the outer zone, a small vibration will be applied to the teacher so that the operator is aware of the transition. In case of keeping the master in that area, the vibration will disappear after a few seconds and will go to the speed control mode. It is also possible for the operator to decide to return to the internal zone and keep the control mode in position; in this case, the teacher will return to the point where he was before changing the region, so that synchronism between the master and slave positions is guaranteed. The vibration is used to clearly indicate the transition from the control mode in position to the speed control mode.

When the master is in the outer region or zone in the speed control mode, then the master will generate movement orders relative to the slave speed. The velocity module will be proportional to the teacher's penetration into the external zone; that is to say, in said external zone of speed control, the movement speed of the slave will be proportional to the penetration of the master into it, said penetration being the minimum distance that separates the master from the region or inner zone. As for the direction of travel of the slave, this will be indicated by the position of the final effector of the master within that zone

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external In addition, a force proportional to the penetration into the external zone will be reflected to the master device. This will allow the operator to know the speed with which the slave robot is moving.

The transition from the speed control mode to the position control mode will take place through different states that will be notified to the user through haptic information. Therefore, when the operator is leaving the speed control zone, he will perceive a vibration informing of this fact, to subsequently drive the master device to an initial starting position of the position control mode. This initial point of the master device will preferably be the center of the inner zone, while the slave will be stopped in the position in which it was at the time of the transition. At the same time, the master device will be oriented according to the orientation of the clamp or operating tool in the slave device, thus guaranteeing the congruence of orientations between both devices.

Once the master is in the central position and its orientation is congruent with that of the slave, it will return to operation in the position control mode; and so, until the speed control mode was re-entered or the task was completed.

This method of guidance is ideal when the slave's field of work is far superior to that of the master. This is typical of numerous industrial applications, such as the transport of materials, or the inspection and maintenance of facilities. In both cases large displacements are required, the slave robot can cover the entire workspace or be located on a mobile platform that moves it to the desired place. The guidance system described is more efficient than indexing, and the requirement to return to the position control mode from two coherent master and slave positions significantly facilitates operator teleproprioception.

There is another case in which this mode of guidance can be very effective. Specifically, for those cases in which the realization of very precise movements by the slave robot is required. The master and slave workspaces may be similar, but the movements would be scaled up, so that the movements of the slave correspond to much larger movements of the master. This allows to realize the equivalent to what would be the zoom of an image, that is, that a movement of centimeters by the operator can correspond to a millimeter movement by the slave robot. This achieves a high precision of movements that is necessary for delicate handling tasks.

The internal and external regions of the two work modes of the master device could be concentric zones to the center point of the work space of the master device. Thus, the internal region of operation in control mode in position for the master is preferably an inner sphere that surrounds said central point of the working space of the device, and the external region of operation in speed control mode for the master is the external area of maximum scope of the workspace, determined from the perimeter of the aforementioned sphere that forms the interior region. In this way the penetration in the external region, and therefore the speed order that is generated for the slave, can easily be calculated as the distance from the end of the master to the center of the inner sphere, minus the radius of the inner sphere.

The transition of the master from the speed control mode to the position control mode requires that the master enter the inner sphere. In principle, this return does not generate any movement in the slave, and the master is positioned in the center of the inner sphere. In the case that the master and slave configurations are inconsistent in terms of orientations; then, the teacher should be reoriented so that consistency between the master and slave reference systems is maintained. If the slave is at an extreme point of his workspace, it is advisable to take him to a point where the movements of the slave robot are facilitated for manipulation. This reconfiguration should keep the position of the final effector of the robot fixed and therefore a movement of the base would be carried out if possible. This movement will be done as long as it is guaranteed that there is no collision of the slave with its surroundings.

In view of the foregoing, it is found that the method of guiding teleoperated robotic devices to alternate control mode in position and control mode in speed represents an innovation of characteristics unknown until now for this purpose, reasons that together with its practical utility, the provide sufficient grounds to obtain the privilege of exclusivity that is requested.

DESCRIPTION OF THE DRAWINGS

To complement the description that is being made of the invention, and to help a better understanding of the characteristics that distinguish it, this descriptive report is accompanied, as an integral part thereof, of a set of drawings, in which with character Illustrative and not limiting, the following has been represented:

Figure number 1.- Shows a perspective view of a schematic representation of an example of a master device operated by an operator to guide a slave robot, according to the method object of the

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invention.

Figure number 2.- Shows a perspective view of a schematic representation of the master device, in which the working space thereof has been represented divided into the internal region where the control mode is implemented in position and the external region where speed control mode is implemented.

PREFERRED EMBODIMENT OF THE INVENTION

In view of the aforementioned figures, and according to the numbering adopted, an example of teleoperated robotic devices to which the method in question to alternate control mode in position and control mode in speed can be seen can be seen.

Thus, according to Figure 1, an example of a slave robot (3) is observed, specifically a telemanipulator, remotely controlled by a master device (1), whose final effector (5), in this case a drive lever, is operated by an operator (2) to guide the movements of said slave robot (3). Communications (4) between master (1) and slave (3) are transmitted, through their respective controllers (not shown in the figures). These orders are related to both movements and forces exerted by both devices.

For its part, Figure 2 shows the workspace (6) of the final effector (5) of the master device (1) which is divided into two regions of different performance: an internal region (7), where a mode of implementation is implemented. control in position, which occupies a certain area, normally similar to a sphere, that surrounds the central point of the mentioned workspace (6); and an external region (8), in which a speed control mode is implemented, and occupies the external maximum range area of the final effector (5) in the workspace (6) beyond the perimeter determined by the inner region (7).

A specific example of embodiment of the invention is the use of a Sensable Omni Phantom haptic device as a master device (1) and any commercial robot, such as Kuka's KR-150 robot as a slave robot (3). In said example, the operating radius of the slave robot (3) is close to two and a half meters, while the workspace (6) of the master device (1) constituted by the said haptic device is close to a sphere of only 10 centimeters of radius.

Thus, by applying the guiding method of the invention, an spherical zone with a radius of, for example, 8 centimeters with center is adapted as an internal region (7) of the working area (6) of the master device (1). central area of the work space (6) of the Omni, to implement in it the control mode in position of the slave robot (3). And, in parallel, an external region (8) of said master device (1), covering the rest of the space of its work (6), is adapted to implement in it the speed control mode of the slave robot (3).

The coupling of both devices, that is, the Omni haptic device and the Kr-150 robot, would usually be done by speed control or by scaling the positions of both devices. The guidance method proposed here allows to implement a speed guidance mode for large displacements, and a position guidance mode for those areas where high precision is needed.

Communications (4) between the two devices are produced, for example, by means of a PC-type computer, for which, the necessary drivers (provided by Sensible for the Phantom) are installed on said computer, and the communications library with the KR 150 robot, preferably Kuka's 'CrossComm' library that allows the transfer of real-time motion commands to the robot controller.

On the PC the position of the Omni that makes up the master device (1) will be checked at all times, and, as noted, the control mode in position for the spherical zone of the internal region (7) and the mode are implemented of speed control for the rest of the Omni workspace (6), which make up the external region (8), also implementing effects of vibration and haptic signaling in each of the transitions between the internal region (7 ) and the external region (8) of the final effector (5) of the master device (1) that indicate to the operator (2) that it handles the change from one work mode to another.

In summary, the recommended method to avoid instabilities in the transition between the control modes in position and speed, includes the adaptation of the master device (1) to divide its work area (6) into an internal region (7) where implements the position control mode of the slave robot (3), and an external region (8) where the speed control mode is implemented, contemplating the use of an Ethernet network to carry out communications (4) between the PC of the master device (1) and the slave robot controller (3) to transmit both movement orders and forces exerted by both devices.

The method also contemplates the adaptation of the master device (1) to produce effects

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of vibration perceptible by the operator (2) in each of the transitions between the internal region (7) and the external region (8) of the final effector (5), indicating the change from one control mode to another.

It is also important to note that, according to the proposed method, in the control mode in

5 position, where the movements of the master (1) correspond to similar movements of the slave, forces are reflected to the master that correspond to the forces exerted by the slave robot (3) on the environment; that, when the transition from the external region (8) to the internal one (7) occurs, the effector of the master device (1) returns to the point where it was before changing the region, guaranteeing synchronism between the master positions and slave and looking for the highest degree of teleproprioception possible for the operator; and that when the

The master is in the external region (8), and therefore in speed control mode, the travel speed of the slave (3) is proportional to the penetration of the effector (5) into said external region (8), said being penetration the minimum distance that separates the effector (5) from the internal region (7). Also, in said external region (8), the direction of travel of the slave (3), is indicated by the position of the effector (5) within said external zone (8), and, also in said external region (8), the proportional force is reflected to the master device (1)

15 penetration into her.

Describing sufficiently the nature of the present invention, as well as the way of putting it into practice, it is not considered necessary to make its explanation more extensive so that any person skilled in the art understands its scope and the advantages that derive from it, stating that, within its essentiality,

20 may be put into practice in other embodiments that differ in detail from that indicated by way of example, and which will also achieve the protection that is sought as long as it is not altered, changed or modified its fundamental principle.

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Claims (7)

1.-GUIDING METHOD OF TELEOPERATED ROBOTIC DEVICES TO ALTERNATE POSITION CONTROL MODE AND SPEED CONTROL MODE, applicable to robot guidance operations where a human operator (2) uses a master device (1), by operating a final effector (5) that covers a certain workspace (6), to guide, through a communications network (4), a slave robot (3) that performs the operation in a remote environment, characterized in that it includes the adaptation of said master device (1) to divide its work zone (6) into an internal region (7) where the control mode in position of the slave robot (3) is implemented, and an external region (8) where the speed control mode, contemplating the use of a communications network (4) between the controllers of the master devices (1) and slave robot (3) to transmit both movement orders and forces exerted by both devices. 2.- GUIDING METHOD OF TELEOPERATED ROBOTIC DEVICES FOR ALTERNATING CONTROL MODE IN POSITION AND SPEED CONTROL MODE, according to claim 1, characterized in that the internal region (7) of the master device (1) occupies an approximately spherical zone with center in the center of the work area (6) and less than a maximum radius of radius of the final effector (5), and the external region (8) covers the rest of the space occupied by the work area (6). 3.- GUIDING METHOD OF TELEOPERATED ROBOTIC DEVICES TO ALTERNATE CONTROL MODE IN POSITION AND SPEED CONTROL MODE, according to claim 1 or 2, characterized in that it contemplates the adaptation of the master device (1) to produce perceptible vibration effects by the operator (2) in each of the transitions between the internal region (7) and the external region (8) of the final effector (5), indicating the change of control mode. 4.- GUIDING METHOD OF TELEOPERATED ROBOTIC DEVICES FOR ALTERNATING CONTROL MODE IN POSITION AND CONTROL MODE IN SPEED, according to any of claims 1-3, characterized in that in the control mode in position, where the teacher's movements (1 ) correspond to similar movements of the slave, forces are reflected to the master that correspond to the forces exerted by the slave robot (3) on the environment. 5.- GUIDED METHOD OF TELEOPERATED ROBOTIC DEVICES FOR ALTERNATING CONTROL MODE IN POSITION AND SPEED CONTROL MODE, according to any of claims 1-4, characterized in that, when the transition from the external region (8) to the internal (7), the final effector of the master device (1) returns to the central point of the internal region, ensuring synchronism between the master and slave positions. 6.- GUIDED METHOD OF TELEOPERATED ROBOTIC DEVICES FOR ALTERNATING CONTROL MODE IN POSITION AND SPEED CONTROL MODE, according to any of claims 1-5, characterized in that, when the master is in the external region (8), and by both in speed control mode, the travel speed of the slave (3) is proportional to the penetration of the effector (5) into said external region (8), said penetration being the minimum distance that separates the effector (5) from the internal region (7), because in said external region (8), the direction of travel of the slave (3), is indicated by the orientation of its final effector; and because a force proportional to the penetration into the external zone (8) is reflected to the master device (1). ES 2 416 931 A1 SPANISH OFFICE OF THE PATENTS AND BRAND Application no .: 201132146 SPAIN Date of submission of the application: 12-30-2011 Priority Date: REPORT ON THE STATE OF THE TECHNIQUE 51 Int. Cl.: B25J3 / 04 (2006.01) RELEVANT DOCUMENTS

Category

56 Documents cited Claims Affected

TO

EP 0816020 A1 (KOMATSU MFG CO Ltd.) 07.01.1998, summary; page 9, line 7 - page 11, line 1; Figures 1-3B, 7. 1.2

TO

JP H02145272 A (TOSHIBA CORP) 04.06.1990, the whole document. one

TO

US 6801008 B1 (JACOBUS et al.) 05.10.2004, the whole document. one

TO

WO 9111298 A1 (SARCOS GROUP) 08.08.1991, summary; figure 2. one

TO

US 3282442 A (BIGGLEY et al.) 01.11.1966

Category of the documents cited X: of particular relevance Y: of particular relevance combined with other / s of the same category A: reflects the state of the art O: refers to unwritten disclosure P: published between the priority date and the date of priority submission of the application E: previous document, but published after the date of submission of the application

This report has been prepared • for all claims • for claims no:

Date of realization of the report 23.04.2013

Examiner F. García Sanz Page 1/4

REPORT OF THE STATE OF THE TECHNIQUE Application number: 201132146 Minimum documentation searched (classification system followed by classification symbols) B25J Electronic databases consulted during the search (name of the database and, if possible, terms of search used) INVENES, EPODOC State of the Art Report Page 2/4  WRITTEN OPINION Application number: 201132146 Date of Completion of Written Opinion: 04/23/2013 Statement

Novelty (Art. 6.1 LP 11/1986)

Claims Claims 1-6 IF NOT

Inventive activity (Art. 8.1 LP11 / 1986)

Claims Claims 1-6 IF NOT

The application is considered to comply with the industrial application requirement. This requirement was evaluated during the formal and technical examination phase of the application (Article 31.2 Law 11/1986).  Opinion Base.- This opinion has been made on the basis of the patent application as published. State of the Art Report Page 3/4  WRITTEN OPINION Application number: 201132146  1. Documents considered.- The documents belonging to the state of the art taken into consideration for the realization of this opinion are listed below.

Document

Publication or Identification Number publication date

D01

EP 0816020 A1 (KOMATSU MFG CO Ltd.) 07.01.1998

D02

JP H02145272 A (TOSHIBA CORP) 04.06.1990

D03

US 6801008 B1 (JACOBUS et al.) 05.10.2004

D04

WO 9111298 A1 (SARCOS GROUP) 08.08.1991

D05

US 3282442 A (BIGGLEY et al.) 01.11.1966

 2. Statement motivated according to articles 29.6 and 29.7 of the Regulations for the execution of Law 11/1986, of March 20, on Patents on novelty and inventive activity; quotes and explanations in support of this statement Document D01, which is considered the closest to the prior art, has as its object (reference numbers apply to this document) a teleoperated robotic device, master / slave type, and a method for its control, applicable to operations for guiding a slave device (2) in which a master device (1) is used, by operating the operator of the final effector (11) of the latter. For this, a method is used in which a plurality of representative points are established on and within a closed space surface (A1) of a working area (A) of the master device, while a plurality of target points corresponding to the plurality of said representative points are established in and within a closed space surface (B1) of a working area (B) of the slave device, master and slave being configured so that, using a communications network, an end effector (21) of the latter carry out an operation in all directions of the space by means of a bilateral (or unilateral) control in control means (3) consisting, for example, of a microcomputer or the like, when the operator operates said final effector (11) of the teacher in all corresponding space directions. That is, both work zones (A, B) occupy essentially spherical space regions (see above all Figures 1-3B). Therefore, document D01, although it has common technical characteristics with the patent application under study and is applied in the same technical field, that is to say, that of the guided methods of robotic devices (master / slave) teleoperated, is fundamentally lacking from: # independent slave position and speed controls; # a clear division into two regions (internal / external) of the teacher's work area, to implement the two Types of slave control cited. As explained above, neither D01 nor any of the documents that have been taken into account, or any combination thereof, seems to be considered of particular relevance to the substantive subject of the invention, to the extent that it can be interpreted. On the other hand, it is not obvious that a person skilled in the art can conceive said subject from said documents. Therefore, the present application seems to meet the requirements of novelty and inventive activity according to the requirements of Articles 6.1 and 8.1 of Patent Law 11/86. State of the Art Report Page 4/4