Device for determining, in at least three spatial directions, force acting on body

Abstract

To determine, in at least three spatial directions (Fx, Fy, Fz, Mx, My, Mz), a force acting on a manipulator.SOLUTION: The device comprises: two actuating elements (20a, 20b), where each of the actuating elements has an operating element (22a, 22b) with a longitudinal axis (L1, L2), and is movable, in particular tiltable, relative to a base element (24a, 24b), an individual force (F1, F2) can be determined, in at least three spatial directions, from the relative movement of the operating element and the base element, and the two actuating elements are arranged relative to one another such that the two operating elements are arranged on sides (25a, 25b) of the base elements facing away from one another; and an evaluation / control unit (30), which detects the individual force (F1, F2) determined by each operating element, and which is designed to calculate, in the at least three spatial directions, the force acting on the object from the two individual forces, in particular, from the sum of the individual forces.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a device for determining forces acting on an object in at least three spatial directions, and to an object equipped with such a device. [Background technology]

[0002] For programming and setting movements of objects, in particular manipulators, such as industrial robots or cobots, it is necessary to move these objects manually by applying forces to the object itself or to corresponding input devices on the object. In many applications, the sensitivity or agility of the respective input device for performing the movements is then a limiting factor. Furthermore, current solutions have a sensitivity that depends on the object position due to the measurement principle of detecting the force.

[0003] Manipulators often have many different degrees of freedom, all six (X, Y, Z, Ry, Ry, Rz), and the ability to control all these axes simultaneously with interpolated Cartesian motion is crucial to making the programming process fast and intuitive. Summary of the Invention [Problem to be solved by the invention]

[0004] It is currently known to measure the motor currents required for the movement of the individual axes of an object, in particular a manipulator, and from there calculate the torques at the respective axes. By subtracting the required holding torque, the changes caused by the forces applied to the axes can be calculated and converted into subsequent movements. However, this has the disadvantage that the forces introduced into the object are only measured indirectly. Depending on the position of the object, in particular the manipulator, leverage effects of different magnitudes can occur that distribute the sensitivity of the solution unevenly over the entire workspace.

[0005] Alternatively, it is known to directly measure the torque of each axis by means of a torque sensor mounted on the axis and to convert the change in torque caused by the force applied to the axis into a subsequent movement. However, this method also has the disadvantage that the force introduced into the object is only measured indirectly and that leverage effects of different magnitudes can occur depending on the position of the object, especially the manipulator. Furthermore, a torque sensor needs to be mounted on each axis, which can lead to high costs.

[0006] The object of the present invention is to provide an apparatus for determining forces acting on an object in at least three spatial directions, by means of which forces introduced into the object can be detected, thereby making a learning or programming process of the object simpler. [Means for solving the problem]

[0007] The object of the present invention is achieved by a device for determining forces acting on an object in at least three spatial directions having the features of claim 1. Advantageous embodiments and developments of the invention are set forth in the dependent claims.

[0008] The device according to the invention for determining forces acting on an object, in particular a manipulator, in at least three spatial directions comprises two actuating elements, each of which has an operating element with a longitudinal axis, the operating elements being movable, in particular tiltable, relative to a base element, and individual forces are determinable in at least three spatial directions from the relative movement between the operating elements and the base element, the two operating elements being arranged relative to one another such that the two operating elements are arranged on mutually opposing faces of the base element, the device further comprising an evaluation / control unit designed to detect the individual forces determined by each actuating element and to calculate the forces acting on the object in at least three spatial directions from the two individual forces, in particular from the sum of the individual forces. The actuation of such actuating elements can be performed intuitively. By the operating elements being arranged on mutually opposing faces of the base element, the user can grip the operating elements with his thumb on one of the operating elements and, for example, his index finger on the other. In this way, the user can simply grab the device, move it in space and carry out a teaching or programming process on the object.

[0009] The forces acting on an object can in particular be calculated in at least three linear spatial directions X, Y, Z. Advantageously, from the relative movement between the operating element and the base element, individual forces can be determined in at least four spatial directions, in particular three linear spatial directions and a direction of rotation about the longitudinal axis of the operating element, which corresponds to a torque acting about the longitudinal axis of the operating element, thereby increasing the accuracy of determining the forces acting on the object.

[0010] Advantageously, in order to further increase the accuracy of determining the forces acting on the object, the evaluation / control unit is designed to calculate the forces acting on the object in six spatial directions from two individual forces, in particular from the sum of the individual forces.

[0011] Preferably, the two base elements are arranged at a distance A from each other, which makes it possible to determine the forces acting on the object in six spatial directions, even if the two individual forces are determined in fewer spatial directions.

[0012] According to a preferred development of the invention, the actuation elements each have an operating element with a longitudinal axis which is tiltable relative to the base element, the tilting movements being detectable simply and with high precision, while being intuitively executable by the user, resulting in an overall simple operation.

[0013] Preferably, the actuation elements are designed like a joystick or a trackpoint, which may allow for simple and intuitive handling. According to a preferred embodiment of the invention, it is provided that the evaluation and control unit calculates the forces acting between the two actuating elements in at least three spatial directions based on the individual forces, in particular from the difference between the individual forces. Further determination of the forces acting between the two actuating elements allows further applications.

[0014] In particular, in a preferred development, the device can have a deadman switch which switches depending on the force acting between the two actuating elements, for example the force acting between the two actuating elements can be compared with a target value, above or below which a certain event can be triggered, for example the movement of an object can be blocked or a learning or programming process can be activated.

[0015] This allows a single device to simultaneously provide both control of an object's movement based on determining the forces acting on the object, and a deadman's switch based on determining the forces acting between two actuating elements, both of which can be actuated by a user with one hand.

[0016] According to a preferred embodiment of the invention, the actuation element, in particular the operating element, is coupled to an actuator, in particular a vibration motor. Such an actuator allows for example haptic feedback to the user regarding the actuation performed, the motion restriction of the object or the restriction of the force or input, i.e. for example a warning that the user is applying too much force or torque or that the object cannot be moved faster. In principle it is then also possible to provide different haptic feedback patterns in order to feed back different information to the user.

[0017] The object according to the invention, in particular a manipulator, preferably an industrial robot or cobot, is equipped with the device according to the invention as described above. An industrial robot that works together with humans and is not separated from them by protective devices in the production process is called a cobot or collaborative robot. Therefore, in particular the cobot is provided with corresponding safety functions that allow the interaction of the cobot with the user in a safe manner.

[0018] Preferably, the two actuating elements are arranged relative to one another on the surface of the object such that the longitudinal axes of the actuating elements are arranged parallel to one another, which simplifies the evaluation of the individual forces.

[0019] An advantageous development of the invention provides for the device to be removably arranged on the object, in particular in the form of a module, so that it can be easily retrofitted. Preferably, the two actuation elements are arranged on two oppositely facing sides of the surface of the object to enable an ergonomic grip by the user.

[0020] The embodiments of the present invention will be described in detail with reference to the following figures. [Brief description of the drawings]

[0021] [Figure 1] FIG. 2 is a perspective view of an exemplary embodiment of a device according to the invention for determining forces acting on an object in at least three spatial directions; [Diagram 2] FIG. 2 is a top view of the device according to FIG. 1. [Diagram 3] FIG. 2 is a perspective view of the device according to FIG. 1 when placed in a tool receiving part for a robot. [Figure 4] FIG. 4 is a top view of the arrangement according to FIG. [Diagram 5] FIG. 2 is a perspective view of a part of a robot arm in which the device according to FIG. 1 is arranged. [Figure 6] FIG. 6 is another perspective view of a portion of the robot arm according to FIG. [Figure 7] FIG. 1 is a perspective view of a portion of a robot arm incorporating a device for determining forces acting on an object in at least three spatial directions. [Figure 8] FIG. 8 is another perspective view of a portion of the robot arm according to FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] In all figures, the same reference numbers indicate the same or functionally similar parts, but for clarity, not all reference numbers are shown in all figures. 1 and 2 show an exemplary embodiment of a device 10 for determining forces acting on an object in at least three spatial directions Fx, Fy, Fz, Mx, My, Mz. The spatial directions are the three linear directions X, Y, Z and the rotations around these three linear directions. If the forces acting on the object are determined in three spatial directions, it is in particular the three linear directions X, Y, Z. Preferably, the forces acting on the object are determined in all six spatial directions Fx, Fy, Fz, Mx, My, Mz, i.e. the linear forces Fx, Fy, Fz in the three directions X, Y, Z and the torques My, My, Mz around these three axes.

[0023] The device comprises two actuating elements 20a, 20b, each of which has an operating element 22a, 22b with a longitudinal axis L1, L2, which is movable, in particular tiltable, relative to a base element 24a, 24b. For example, each of the actuating elements 20a, 20b can be designed like a joystick or a track point. Each base element 24a, 24b has a first face 25a, 25b and a second face 26a arranged substantially parallel thereto, the second face of the second base element 20b being hidden in the figure. The operating elements 22a, 22b are arranged in particular on the first faces 25a, 25b. The two actuating elements 20a, 20b are designed in particular to have the same structure.

[0024] According to the invention, the two actuating elements 20a, 20b are arranged relative to one another such that the two operating elements 24a, 24b are arranged on mutually opposing faces 25a, 25b of the base elements 24a, 24b. The other two faces 26a of the base elements 24a, 24b are in particular arranged facing one another. The two actuating elements 20a, 20b are in particular arranged at a distance A from one another.

[0025] The actuation elements 20a, 20b are in particular arranged relative to one another in such a way that the longitudinal axes L1, L2 of the two operating elements 24a, 24b are arranged parallel to one another and in particular coincide (see FIG. 2).

[0026] The actuation elements 20a, 20b, in particular the operating elements 24a, 24b, can be coupled to actuators (not shown), in particular vibration motors, in order to enable haptic feedback to be given to the operating elements 24a, 24b when actuated by a user.

[0027] For each actuation element 20a, 20b, from the relative movement between the operating element 22a, 22b and the base element 24a, 24n, individual forces F1, F2 can be determined in at least three spatial directions, in particular in at least three linear spatial directions X, Y, Z and preferably further in a direction of rotation Mz about the longitudinal axis L1, L2 of the operating element 24a, 24b.

[0028] The device 10 further comprises an evaluation / control unit 30 designed to detect the individual forces F1, F2 determined by each actuating element 20a, 20b and to calculate from the two individual forces F1, F2 the force acting on the object in at least three spatial directions, in particular in the three linear spatial directions Fx, Fy, Fz, but preferably in all six spatial directions Fx, Fy, Fz, Mx, My, Mz. This calculation can be carried out, for example, from the sum of the individual forces F1, F2, in particular taking into account the distance A of the two actuating elements 20a, 20b. Even if the individual actuating elements 20a, 20b determine the individual forces F1, F2 in less than six spatial directions, the fact that two actuating elements 20a, 20b are used and are arranged at a distance from each other allows the calculation of the force F acting on the object as a whole to be carried out in all six spatial directions Fx, Fy, Fz, Mx, My, Mz.

[0029] The evaluation / control unit can furthermore be designed to calculate the force acting between the two actuating elements 20a, 20b based on the individual forces F1, F2, in particular from the difference between the individual forces F1, F2, in at least three spatial directions, preferably in all six spatial directions Fx, Fy, Fz, Mx, My, M, in which case also in particular taking into account the distance A of the actuating elements 20a, 20b. The force acting between the two actuating elements 20a, 20b can then be used, for example, for switching a deadman switch 40. The deadman switch 40 can then be used, for example, to detect whether a user is touching the actuating elements 20a, 20b and only in that case to activate a learning or programming process. If the pressure is too low or too high, the deadman switch 40 can stop or prevent the movement of the object.

[0030] The actuation elements 20a, 20b and the evaluation and control unit 30 can be arranged in a housing 50 which can be removably arranged on the object. The operating elements 22a, 22b are then accessible from outside the housing 50 to enable operation. The operating elements 22a, 22b are then arranged in particular on two oppositely facing faces 51, 52 of the surface of the housing 50. The housing 50 can be attached using fastening devices such as screws, magnets, snap connections, etc.

[0031] Figures 3 and 4 show the arrangement of the device 10 in a tool housing 60, which can for example be arranged in a robot head 72 of a robot arm 70, as shown in Figures 5 and 6. The robot arm 70 can be an industrial robot or a collaborative robot, a so-called cobot robot arm 70.

[0032] Since the device 10 is able to determine the forces acting on the robot arm 70 applied by the user and convert them into control signals in order to enable the movement to be automatically followed after the teaching process, using such a device 10 allows the user to simply teach the movement of the robot arm 70 by gripping the area of ​​the free end of the robot arm 70, in particular the robot head 72, in particular the tool receiving part 60 therein, and guiding the robot arm 70 in the desired direction.

[0033] 7 and 8 differs from the previous embodiment only in that the device 10 is not removably arranged in the tool receiving part 60, but is integrated in the tool holder 60, i.e. arranged in the same housing. Alternatively, the device 10 can be integrated in the robot head 72 or elsewhere in the robot arm 70, in which case it is preferable to arrange the device 10 as far as possible from the axis of rotation or pivot of the robot arm 70, in order to allow a longer lever to reduce the forces required for the movement of the robot arm 70. [Explanation of symbols]

[0034] 10...device 20a...Operating element 20b...Operating element 22a...operation element 22b…operation element 24a…Bass element 24b…Bass element 25a...side 25b...side 26a…side 30…Evaluation / control unit 40…Deadman's Switch 50…Housing 60...Tool storage section 70…Robot arm 72...Robot head A…Distance L1…longitudinal axis L2…longitudinal axis

Claims

1. A device (10) for determining forces acting on an object, in particular a manipulator, in at least three spatial directions (Fx, Fy, Fz, Mx, My, Mz), comprising: two actuating elements (20a, 20b), each of which has an operating element (22a, 22b) with a longitudinal axis (L1, L2), which are movable, in particular tiltable, with respect to a base element (24a, 24b), and from the relative movement between the operating elements (22a, 22b) and the base element (24a, 24b) individual forces (F1, F2) are determinable in at least three spatial directions, and which are arranged relative to one another such that the two operating elements (22a, 22b) are arranged on mutually opposite faces (25a, 25b) of the base element (24a, 24b); an evaluation / control unit (30) designed to detect the individual forces (F1, F2) determined by each actuation element (20a, 20b) and to calculate a force acting on the object in at least three spatial directions (Fx, Fy, Fz, Mx, My, Mz) from the two individual forces (F1, F2), in particular from the sum of the individual forces, Apparatus (10).

2. characterised in that from the relative movement between the operating elements (22a, 22b) and the base element (24a, 24b) individual forces (F1, F2) can be determined in at least four spatial directions (Fx, Fy, Fz, Mx, My, Mz), in particular in three linear spatial directions and in the direction of rotation about the longitudinal axis (L1, L2) of the operating elements (22a, 22b), 2. The apparatus of claim 1.

3. characterised in that the evaluation / control unit (30) is designed to calculate the forces acting on the object in six spatial directions (Fx, Fy, Fz, Mx, My, Mz) from the two individual forces (F1, F2), in particular from the sum of the individual forces.

3. Apparatus according to claim 1 or 2.

4. The two base elements (24a, 24b) are arranged at a distance (A) from each other, An apparatus according to any one of claims 1 to 3.

5. characterised in that the actuating elements (20a, 20b) are designed like a joystick or a trackpoint, An apparatus according to any one of claims 1 to 4.

6. characterised in that the evaluation / control unit (30) is designed to calculate, on the basis of the individual forces (F1, F2), in particular from the difference between the individual forces, the forces acting between the two actuating elements (20a, 20b) in at least three spatial directions (Fx, Fy, Fz, Mx, My, Mz). An apparatus according to any one of claims 1 to 5.

7. The device (10) is characterized in that it has a deadman switch (40) which switches depending on the force acting between the two actuating elements (20a, 20b), An apparatus according to any one of claims 1 to 6.

8. characterised in that the operating elements (20a, 20b), in particular the actuating elements (22a, 22b), are coupled to actuators, in particular vibration motors. An apparatus according to any one of claims 1 to 7.

9. An object, in particular a manipulator, preferably an industrial robot or cobot, equipped with a device (10) according to any one of the preceding claims.

10. characterised in that the two actuating elements (20a, 20b) are arranged relative to one another on the surface of the object such that their longitudinal axes (L1, L2) are arranged parallel to one another, 10. The object of claim 9.

11. The device (10) is detachably arranged on the object, 11. An object according to claim 9 or 10.

12. the two actuating elements (20a, 20b) are arranged on two opposite sides of the surface of the object, An object according to any one of claims 9 to 11.

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