TECHNICAL FIELD

The present invention relates to obtaining information of a remote target in order to perform operations on it with a remotely operated robot.

BACKGROUND ART

Performing operations remotely is desirable e.g. in cases where the target is difficult to access (offshore,

underwater, mine) or the environment at the target is hazardous (explosive, cold, warm) . When performing

operations on a remote target with a remotely operated robot, an operator is dependent on feedback information provided by technical feedback devices such as cameras and different types of sensors. For example, a camera can provide a visual feedback and enable the operator to steer the robot in an appropriate way to complete the desired operations. Remotely operated systems are known where a plurality of cameras with fixed positions provide different views of a target. It is furthermore known to make a camera movable by providing it with some kind of actuators such as electrical motors, or by attaching it to a robot arm or another movable part of the robot such that the camera always shows the robot tool and moves along as the operation on the target is performed. A drawback with the stationary cameras is that the

arrangement is very inflexible in that the view of a camera cannot be changed in case the current view is occluded e.g. by the robot or by the target itself. Alternatively a great number of cameras is needed to always ensure a good view on the target. A drawback with the movable cameras is that they are more complicated and expensive than stationary cameras, and yet their movements are strongly restricted by the reach of the actuator mechanisms they are provided with. A

drawback with a camera attached to a robot arm is again the inflexibility of choosing the view. A view from the

direction of the robot arm may not be optimal for performing certain operations on the target, and a camera attached to a robot arm also takes up space and may be restrictive for the movements of the robot.

In view of the drawbacks related to conventional methods of obtaining information of a remote target there remains a desire to develop an improved method.

SUMMARY OF THE INVENTION

One object of the invention is to provide an improved method of obtaining information of a remote target, whereby the information can be obtained in a flexible way even by using only a single simple feedback device.

This object is achieved by the method according to appended claim 1, and by the system according to the appended claim 9.

The invention is based on the realization that by using a robot tool to reposition a feedback device the location of the same in relation to the target can be chosen in a very flexible way.

According to a first aspect of the invention, there is provided a method for obtaining information of a remote target. The method comprises the steps of: providing a robot configured to be steered from a remote location by an operator, the robot comprising a base and a tool holder having a plurality of degrees of freedom in relation to the base, the tool holder being configured to receive a tool or tools, at least one tool being configured to perform an operation on the target; and providing a feedback device configured to provide information of the target to the operator for enabling appropriate steering of the robot, the feedback device being immobile in relation to the target during the performance of the operation on the target.

The method is characterized by a step of using a tool attached to the tool holder to reposition the feedback device in relation to the target. By using a robot tool for repositioning the feedback device the flexibility of the robot is effectively utilized for receiving a desired view of the target. According to one embodiment of the invention the feedback device is one of the following: a still camera, a video camera, a thermographic camera, a temperature sensor, a gas sensor, a humidity sensor, a distance measurement device. The mentioned feedback devices are examples that are well suited to be used in the context of the present method.

According to one embodiment of the invention the method further comprises the step of mounting the feedback device to a positioning mechanism having a plurality of degrees of freedom enabling positioning of the feedback device at a plurality of locations and/or orientations in relation to the target. By this means the repositioning of the feedback device is facilitated.

According to one embodiment of the invention the method further comprises the step of providing the feedback device with an attachment means enabling attachment of the feedback device at a plurality of locations and/or orientations in relation to the target. By this means the repositioning of the feedback device is facilitated.

According to one embodiment of the invention the attachment means comprises one of the following: a magnet, a suction cup, a Velcro™ fastener. The mentioned attachment means are examples of flexible attachment means. According to one embodiment of the invention the feedback device comprises wireless communication means. Wireless communication furthermore increases the flexibility of repositioning the feedback device. According to one embodiment of the invention the feedback device comprises a battery as a power source. A battery as a power source furthermore increases the flexibility of repositioning the feedback device.

According to one embodiment of the invention the robot is provided with a camera giving the operator feedback of the location of the feedback device. By this means repositioning of the feedback device is facilitated.

According to a second aspect of the invention, there is provided a system for obtaining information of a remote target. The system comprises a robot configured to be steered from a remote location by an operator, the robot comprising a base and a tool holder having a plurality of degrees of freedom in relation to the base, the tool holder being configured to receive a tool or tools, at least one tool being configured to perform an operation on the target, and a feedback device configured to provide information of the target to the operator for enabling appropriate steering of the robot, the feedback device being immobile in relation to the target during the performance of the operation on the target. The system is characterized in that the feedback device is configured to be repositioned in relation to the target by a tool attached to the tool holder. By enabling the use of a robot tool for repositioning the feedback device the flexibility of the robot is effectively utilized for receiving a desired view of the target. BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in greater detail with reference to the accompanying figure 1 showing one

embodiment of the invention. DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to figure 1, a remotely controlled robot 10 is provided with a movable platform 20 functioning as a base supporting a carousel 30, a lower robot arm 40 and an upper robot arm 50. A robot wrist 60 is provided with a tool holder 70 to which a first tool 80 comprising a paint brush 90 is attached. The tool holder 70 has six degrees of freedom in relation to the movable platform 20, namely about the first, second, third, fourth, fifth and sixth rotational axes 100, 110, 120, 130, 140, 150. The first tool 80 is configured to brush paint on a canvas 160, the brushing of paint being in the present example an operation, and the canvas 160 being a target on which the operation is

performed. The robot 10 is steered from a remote location 170 by an operator 180 who receives feedback of the relative positions of the paint brush 90 and the canvas 160 via a first camera 190, thus enabling the operator 180 to

appropriately steer the robot 10, in this case by means of a joystick 200, to finish the painting 210. The first camera 190 may be installed at the workspace in advance, or it may be carried to the workspace by the robot 10 just before the brushing of paint is started. The first camera 190 is immobile in relation to the canvas 160 during the brushing of paint. The first camera 190 may be of any suitable type such as a still camera, a video camera, or a thermographic camera, and there may be any suitable number of the first cameras 190. The operator 180 may want to look at the painting 210 from a different view. To this end a second tool 220 is provided with which the operator 180 is able to catch hold of the first camera 190 and reposition it to a desired location. The robot 10 comprises a tool magazine 230 storing tools 80, 220 that are not in use at the moment of observation. The robot 10 is also provided with a second camera 240 that gives the operator 180 feedback of the location of the first camera 190 for facilitating the repositioning of the same. The first camera 190 is mounted to a tripod 250 having two extension arms 260 rotatable about respective joints 270 to thereby enable positioning of the first camera 190 at a plurality of locations and orientations in relation to the canvas 160. The first camera 190 is additionally provided with a magnet 280 attached to the camera housing via a ball joint 290. The first camera 190 can be dismounted from the tripod 250 and attached by means of the magnet 280 to a structure comprising magnetic material, such as an iron bar 300 attached on a wall, and then oriented appropriately about the ball joint 290. Alternatively, the first camera 190 can be provided with other suitable attachment means such as a suction cup, a Velcro™ fastener or the like.

The first and second cameras 190, 240 as well as the robot 10 communicate wirelessly with a robot controller 310 comprising a transceiver (not shown) . The first and second cameras 190, 240, the robot 10 and the transceiver are provided with respective antennas 320 to enable the wireless communication. The robot controller 310 communicates in its turn with the operator 180 via a network 330 and a general purpose computer 340 provided with appropriate software for presenting the feedback information from the first and second cameras 190, 240 to the operator 180, and for sending control commands from the operator 180 to the robot 10. The first camera 190 preferably comprises a battery (not shown) as a power source, the operator 180 being able to charge the battery by connecting the first camera 190 to a battery charger (not shown) .

The invention is not limited to the embodiments shown above, but the person skilled in the art may modify them in a plurality of ways within the scope of the invention as defined by the claims. Thus, the invention is not limited to obtaining information provided by a camera or cameras 190, but it may also be applied to obtaining information provided by sensors (temperature, gas, humidity) , distance

measurement devices (laser, radar, sonar), and the like.