Collision-detection device for gripper systems and method for detecting a collision

Abstract

A collision-detection device for a gripper system of a handling device, with at least two gripping jaws arranged on a flange plate, detects collisions between the gripper system and an object. The device includes a safety device configured to lock the collision-detection device to the gripper system and/or dampen the collision-detection device with the gripper system. The safety device is configured to receive from the flange a change in force and/or a change in torque generated by contact between the gripping jaws and the object. The device further includes a sensor configured to detect a change in distance which exceeds a predetermined permissible change in distance between the flange plate and a reference, the change in distance resulting from the at least one of the change in force and the change in torque.

Claims

1. A collision-detection device for a gripper system of a handling device for detecting collisions between the gripper system and an object, wherein the gripper system has at least two gripping jaws which are configured to move with respect to one another in order to open and close and which are arranged on a flange plate, comprising: at least one safety device configured to at least one of lock the collision-detection device to the gripper system, and dampen the collision-detection device with the gripper system, the at least one safety device configured to receive from the flange plate at least one of a change in force and a change in torque generated by contact between at least one of the at least two gripping jaws and the object; and at least one sensor configured to detect a change in distance which exceeds a predetermined permissible change in distance between the flange plate and a reference, the change in distance resulting from the at least one of the change in force and the change in torque.

2. The collision-detection device according to claim 1, wherein the at least one safety device is configured to be selectively activated and deactivated.

3. The collision-detection device according to claim 2, wherein: the at least one safety device includes a locking element; and the locking element is at least one of a frictionally engaging locking element and a positively engaging locking element.

4. The collision-detection device according to claim 2, wherein: the at least one safety device includes a locking element; and the locking element is at least one of an electrical and mechanical locking element.

5. The collision-detection device according to claim 1, wherein the at least one safety device is configured to be activated in monitored areas and configured to be deactivated in non-monitored areas.

6. The collision-detection device according to claim 1, wherein the at least one safety device is at least one of a damping element and a locking element.

7. The collision-detection device according to claim 1, wherein: a sensitivity of the collision-detection device depends on at least one of mechanical damping constants and software-based information of the sensor.

8. The collision-detection device according to claim 1, further comprising: a mounting element mounting the collision-detection device on the flange plate.

9. The collision-detection device according to claim 1, further comprising: at least one of an electrical and a fluidic conduction device which extends at least from the gripping jaws to the flange plate.

10. A method of detecting a collision between a gripper system of a handling device and an object, comprising: generating at least one of a force and a torque by contact between a gripping jaw of the gripper system and the object; transferring the at least one of the force and the torque from the gripping jaw of the gripper system through a flange plate supporting the gripping jaw to a safety device of a collision-detection system; detecting with a sensor a change in distance between the flange plate and a reference resulting from the at least one of the force and the torque; and initiating an emergency stop when the detected change in the distance exceeds a predetermined value.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages and embodiments emerge from the appended drawings, in which:

(2) FIG. 1 shows a schematic plan view of a partial section of a first inventive embodiment of the collision detection device in an unsafe environment;

(3) FIG. 2 shows a schematic side view of the first inventive embodiment of the collision-detection device (shown in FIG. 1) in an unsafe environment;

(4) FIG. 3 shows a further schematic illustration of the first inventive embodiment of the collision-detection device in a safe environment;

(5) FIG. 4 shows a further schematic illustration of the first inventive embodiment of the collision-detection device;

(6) FIG. 5 shows a schematic illustration of a second inventive embodiment of the collision-detection device in an unsafe environment; and

(7) FIG. 6 shows a further schematic illustration of a second inventive embodiment of the collision-detection device in a safe environment.

DETAILED DESCRIPTION

(8) FIG. 1 shows a schematic plan view of a partial section through a first inventive embodiment of the collision-detection device 10 in an unsafe environment. This collision-detection device 10 is arranged here on a gripper system 2 of a handling device (not illustrated in more detail) and has, in particular, a sensor 12 and a safety device 13.

(9) The safety device 13 is suitable and provided here for locking the collision-detection device 10 with a flange plate 6, on which, as illustrated in more detail in FIGS. 2-4, the gripper system 2 and, in particular, the gripping jaw 5 are arranged, and to damp this flange plate 6. In particular, in this context the safety device 13 has in this embodiment a damping element 14 and an optional positively engaging locking device 18.

(10) The damping element 14 is embodied in this embodiment as an airbag which can, in particular, also act as a locking element for locking the flange plate 6. Air can be fed into or discharged from the damping element 14 via the inlet and outlet valve 15.

(11) Furthermore, it is apparent from FIG. 1 that the positively engaging locking element 18 is not activated and accordingly, in particular, an activation element 19 is not located in a recess 20 of a mounting element 7. Accordingly, FIG. 1 illustrates the situation in which the handling device or the gripper system 2 is in an unsafe environment in which collisions with people are possible. Accordingly, the damping element 14 merely also performs its damping effect, and does not perform a locking function. The abovementioned mounting element 7 serves here, in particular, to attach the collision-detection device 10 to the flange plate 6 of the handling device.

(12) The sensor 12 is preferably a distance-measuring device which in this exemplary embodiment detects a change in distance of the flange plate 6. The arrow characterizes here an angle of 120°, and therefore the position of a further sensor in the event of three sensors being arranged. Four sensors are provided, which means they are correspondingly arranged at an angle of 90° with respect to one another.

(13) The reference symbol 8 also characterizes a central attachment device on which the flange plate 6 and the gripping jaw 5 are arranged and about which they can be pivoted together through 6 degrees of freedom in an unlocked state, conditioned by the geometric flexibility.

(14) FIG. 2 shows a schematic side view of the first inventive embodiment (shown in FIG. 1) of the collision-detection device 10 in an unsafe environment. In this illustration it is also apparent here that the collision-detection device 10 is not locked by the frictionally engaging locking element 18 and the damping element 14. The inlet and outlet valve 15 of the damping element 14 is open in the non-locked state here, so that an air flow L is possible in both directions, and a relatively low air pressure in comparison with the locked state is present in the damping device 14, in particular the airbag.

(15) When there is a force effect on the gripping jaw 5, the movement of the flange plate which results from this causes the air pressure within the airbag to change and triggers a movement of the gripping jaw 5, as shown in FIG. 4. During this movement, the gripping jaw 5 can preferably pivot through 6 degrees of freedom about the central attachment device 8. The movement is also made possible here, in particular, by the structure of the damping element 14, which permits extension of the damping element 14. In addition, this change in the air pressure brings about a change in distance of the flange plate 6, which is detected by the sensor 12 and is passed on to a controller (not illustrated) for the purpose of stopping the travel movement of the handling device.

(16) The reference symbol B characterizes the direction of movement of the activation element 19 of the positively engaging locking element 18.

(17) FIG. 3 shows a further schematic illustration of the first inventive embodiment of the collision-detection device 10 in a safe environment. In this safe environment a collision with people or items is not conceivable, and the collision-detection device 10 is therefore in a locked state, so that relatively large forces and torques can be absorbed at the gripping jaw 5.

(18) The activation element 19 of the positively engaging locking element 18 is accordingly in the recess 20 of the mounting element 7. Furthermore, in this embodiment the damping element 14 also acts as a locking element, for which purpose the inlet and outlet valve 15 is closed so that an air flow from the inside to the outside and the outside to the inside is not possible and an air pressure in the interior of the damping element 14 is higher than in the non-locked state. As a result of this relatively high air pressure, in particular relatively small movements of the flange plate 6 are permitted. As is apparent from FIG. 3, an air flow L exclusively in the interior of the damping element 14 is possible. When there is a force effect on the gripping jaw 5, a movement of the flange plate 6 is generated, as a result of which the air pressure in the interior of the damping element 14 increases and expands. The change in pressure of the flange plate 6 is detected by the sensor (not illustrated here). However, in this context a greater increase in air pressure is permitted in a safe environment than in an unsafe environment, before a stop of the handling device is generated.

(19) FIG. 4 shows a further schematic illustration of the first inventive embodiment of the collision-detection device 10. This illustration shows here, in particular, the movement of the gripping jaw 5 and of the flange plate 6 about the central-attachment device 8 in an unsafe environment (not locked) in the event of a collision.

(20) In particular it is conceivable here that the air pressure in the interior of the damping element 14 increases through an air flow L from the outside into the interior of the damping element 14 as a result of the collision or the forces and torques which increase as a result thereof and the change in distance of the flange plate 6. As a result, the damping element 14 expands owing to the structure in the longitudinal direction and brings about pivoting of the gripping jaw 5, so that injuries in the case of collisions with people or damage in the case of collisions with items can be prevented. At the same time, this change in distance of the flange plate 6 is also detected by the sensor 12 and correspondingly a stop of the travel movement of the handling device is generated by means of a control device (not illustrated).

(21) The reference signs or arrows F and M characterize the forces and torques acting on the gripping jaw 5.

(22) FIG. 5 shows a schematic illustration of a second inventive embodiment of the collision-detection device 10 in an unsafe environment. In this embodiment, the safety device 13 has a wobble plate 32 with mount 34 as a damping element. Furthermore, a pneumatic cylinder 30 is provided as the locking element. Since the handling device 1 is located in an unsafe environment in which collisions with objects and, in particular, people and items are tendentially possible, the handling device 1 is not locked by means of the pneumatic cylinder 30.

(23) If a collision then takes place between the gripping jaw (not illustrated in this illustration) which is arranged on the flange plate 6 and the object detects the sensor 12, which is preferably a proximity switch here, detects a change in distance of the wobble plate 32 with respect to the sensor 12, as a result of which an emergency stop of the handling device 1 is initiated.

(24) The reference sign 7 also in turn characterizes here a mounting element 7 by means of which the collision-detection device 10 is arranged on the handling device 1. It is apparent here that the wobble plate 32 is connected to the mounting element 7.

(25) A collision of an object with the housing or the mounting element 7 of the collision-detection device 10 can additionally be prevented, for example, by means of a capacitive sensor skin (not illustrated) on the mounting element 7.

(26) FIG. 6 shows a further schematic illustration of a second inventive embodiment of the collision-detection device 10 in a safe environment. In this safe working environment, collisions with people are not possible, so that the wobble plate 32 is secured here in a frictionally engaging fashion by means of the pneumatic cylinder 30. The connection of the pressure necessary for this can be made by means of a pneumatic valve which is embedded in a suitable safety circuit.

(27) When there is a collision of the gripping jaw, a change in force and torque is correspondingly transmitted again to the wobble plate 32 and its mount 34 via the flange plate 6, and a resulting change in distance is detected by the sensor 12.

(28) The applicant reserves the right to claim all features disclosed in the application documents as essential to the disclosure insofar as they are novel, either individually or in combination, with respect to the prior art. It is also to be noted that in the individual figures features have also been described which can be advantageous in themselves. A person skilled in the art will immediately recognize that a specific feature which is described in a figure can be advantageous even without transferring further features from this figure. In addition, a person skilled in the art will recognize that advantages can also arise through a combination of a plurality of features which are shown in individual figures or in different figures.