Construction robot having parallel manipulator

Abstract

The invention relates to a construction robot (10) for carrying out construction work on a construction site object. The construction robot comprises: a mobile platform (12); an end effector (16), the end effector (16) having at least one tool or a tool holder for receiving a tool; and a parallel manipulator (18), the end effector (16) and the mobile platform (12) being interconnected via the parallel manipulator (18), and the end effector (16) having at least one contact element (24) which is designed to contact the construction site object to be processed during construction work. The invention allows for carrying out construction works with particularly high precision.

Description

[0001] Construction robot with parallel manipulator

[0002] The invention relates to a construction robot for carrying out construction work on a construction site, comprising a mobile platform, an end effector, wherein the end effector has at least one tool or a tool holder for receiving a tool.

[0003] Construction work on construction sites often requires a high level of positioning accuracy. For example, drilling holes in ceilings often requires a positioning accuracy of 0.5 cm or better so that ceiling elements to be mounted on the ceiling can be properly secured to the holes. If such drilling work is to be carried out using a construction robot, very high demands have to be placed on the achievable positioning accuracy of the construction robot's mobile platform. In particular, it has not been possible to achieve the required positioning accuracy with any type of mobile platform. Mobile platforms that have been used to date are severely limited in their movement capabilities and / or very expensive to manufacture. Furthermore, it is particularly desirable if construction work can be carried out with such positioning accuracy even in difficult-to-reach locations, such as on high ceilings.

[0004] The object of the present invention is therefore to provide a cost-effective construction robot that can perform construction work with particularly high positioning accuracy. Positioning accuracies of 0.5 cm or less are particularly desirable.

[0005] The object is achieved by a construction robot for carrying out construction work on a construction site object, comprising a mobile platform, an end effector, wherein the end effector has at least one tool or a tool holder for receiving a tool, and a parallel manipulator, wherein the end effector and the mobile platform are connected to one another via the parallel manipulator, and wherein the end effector has at least one contact element which is configured to contact the construction site object to be processed during construction work and a sensor system for detecting a pose of the end effector relative to the mobile platform.

[0006] The mobile platform and the end effector can thus be connected to one another, in particular so that they can move relative to one another, via the parallel manipulator. The contact element can then fix the position of the end effector relative to the construction site object, for example a ceiling or wall to be worked on, at least temporarily. The effects of vibrations or other, particularly minor, position changes of the mobile platform on the position of the end effector can be reduced. The positioning accuracy with which a position reached by the end effector is assumed and / or maintained can therefore be particularly high. The sensors can further increase this positioning accuracy by precisely detecting relative movements between the mobile platform and the end effector and initiating corrective measures if necessary.External influences, such as impulse shocks acting on the mobile platform, caused, for example, by gusts of wind, can selectively affect the mobile platform due to the end effector's contact with the construction site element via the contact element, thus leading to a relative displacement of the platform relative to the end effector. This displacement can be detected by the sensors. If necessary, the parallel manipulator can then be counteracted to execute a corrective movement.

[0007] A tool can be understood as an insert tool such as a marking tool, drill, chisel, saw blade, or grinding tool. Alternatively or additionally, a tool can also be understood as a machine tool, in particular one configured to receive and / or use a tool, for example, a marking machine, for example, a controllable paint spray nozzle, a drill, a chiseling machine, a grinding machine, or the like.

[0008] A pose of an object can be understood as a position and / or an attitude, i.e. an orientation, of the object.

[0009] The sensors can detect the pose indirectly. For example, they can rely on position sensors to detect the positions of the parallel manipulator's arms and infer the pose from the data obtained from these sensors.

[0010] Particularly preferably, the sensor system can detect the pose directly, in particular by

[0011] Determination of at least one position and / or orientation of a point on the end effector relative to the mobile platform. Such a direct measurement can eliminate the need for a comparison of the sensor readings with the actual movements of the parallel manipulator, which might otherwise be necessary.

[0012] The sensor system can be designed to operate mechanically. For example, it can mechanically detect the position of an element of the parallel manipulator, particularly relative to the mobile platform.

[0013] Alternatively or additionally, it is also conceivable that the sensor technology works on an optical basis.

[0014] For this purpose, the sensor system may, for example, comprise a laser distance meter. Alternatively or additionally, it may comprise at least one image capture unit. For example, the image capture unit may comprise a black-and-white and / or a color camera.

[0015] It can be located on the mobile platform and / or on the end effector.

[0016] A localization marking may be arranged and / or formed on the end effector and / or the parallel manipulator and / or generally on a part opposite the sensor system. The localization marking may, for example, comprise an AruCo marking or the like.

[0017] In particular, an optical-based sensor system can detect poses contactlessly and at high frequency, particularly with high accuracy. Such sensors can also be lightweight.

[0018] In order to enable continuous monitoring of the pose, the localization marking can be arranged at least partially, preferably completely, in a field of view of the image recording unit.

[0019] The construction robot can also have an acceleration sensor. The acceleration sensor can be formed, in particular, on the end effector. The acceleration sensor can be configured to detect accelerations along at least one direction, preferably two-dimensionally, particularly preferably three-dimensionally. Changes in pose detected by the sensor system and / or the acceleration sensor can be compensated for by an actuating device of the construction robot. The actuating device can be formed on the contact element. Alternatively or additionally, the actuating device can form the contact element.

[0020] It is particularly conceivable that the adjusting device is formed by the parallel manipulator.

[0021] To carry out the construction work, the tool can contact the construction site object being worked on. The contact element can then contact the construction site object in addition to the tool.

[0022] Manufacturing costs can be reduced and production simplified if the parallel manipulator is designed as a passive system.

[0023] The parallel manipulator can be designed, in particular, as a hexapod. Alternatively, it can also be designed as a tripod, sometimes also referred to as a delta manipulator.

[0024] The parallel manipulator can generally have at least three, particularly preferably at least six, degrees of freedom, particularly relative to the mobile platform. At least three degrees of freedom make it possible to work on ceilings or walls without pivoting the mobile platform from the vertical to the horizontal or vice versa. With six degrees of freedom, work can be carried out on both ceilings and walls without pivoting the mobile platform. This also allows construction work to be carried out in otherwise difficult-to-reach locations, for example, if fewer degrees of freedom would otherwise block the path to the desired position due to installation elements such as pipes or cable guides.

[0025] The end effector can also offer additional degrees of freedom. For example, a telescopic element can be arranged on the end effector, allowing the tool to be moved relative to the end effector.

[0026] During construction work on ceilings, the end effector is located on top of the parallel manipulator.

[0027] The parallel manipulator should therefore be designed to provide stable support for the end effector from below during such construction work. Accordingly, it is advantageous if the arms of the parallel manipulator are arranged in such a way that this stable support is provided.

[0028] It is therefore advantageous if the parallel manipulator is designed in such a way that it returns automatically, in particular driven by gravity, from a rest position when the end effector is slightly deflected relative to the mobile platform.

[0029] A possible arrangement of the arms for this purpose can be determined by establishing an energy balance of the system, in particular taking into account potential, kinetic and, if applicable, mechanical energy, for example energy stored in spring elements, and a subsequent search for a local, or preferably a global, energy minimum.

[0030] Construction work at great heights, particularly on ceilings, can be made possible if the mobile platform is an aerial platform. Aerial platforms often have inherently low positioning accuracies and are frequently exposed to external influences, such as gusts of wind. By taking the measures described above, an end effector can be guided with the required positioning accuracy despite such an inherently low positioning accuracy. The construction work can thus be carried out with the required quality. The aerial platform can be a drone. It can have at least one propeller. Flying can also include hovering in the air. The mobile platform can be configured for tethered and / or tetherless execution of construction work. For example, it can be connected to a supply line during a flight. Alternatively or additionally, it can also have a rechargeable battery, in particular a lithium-based one.It is also conceivable for the flight platform to have a fuel cell. Alternatively or additionally, it is also conceivable for the mobile platform to comprise a mobile platform and / or be designed as such. To increase its vertical reach, the mobile platform, particularly if it is designed as a mobile platform, can have a lifting device.

[0031] The construction robot, in particular the end effector, can have a laser distance meter. In this case, at least one position marker can be arranged on the construction site, so that a pose of the construction robot relative to the position marker, preferably to several position markers, can be determined. Alternatively or additionally, it can be configured to be detected by a total station to determine its position and / or orientation. For this purpose, the construction robot can, for example, have a reflector, for example in the form of a prism. Thus, a pose of the construction robot, in particular a position and / or orientation, relative to an absolute reference system of the construction site and / or the total station or the at least one position marker, can be determined.

[0032] Due to obscurations, the work positions at which the construction work is to be carried out and to which the tool, or at least a tip of the tool, must be brought are often not within the field of view of the total station. Therefore, the reflector or the laser distance meter can be arranged on the mobile platform, to which a line of sight is often more easily established. This allows at least a pose of the mobile platform to be recorded and, given knowledge of the relative offset of the mobile platform to the end effector, in particular to the tip of the tool, a pose of the end effector, in particular a pose of the tip of the tool, to be determined.

[0033] If there are several, especially at least three, contact elements, the end effector can be stabilized in several directions relative to the workstation or ceiling. This allows, for example, three-point stabilization.

[0034] The contact element may have at least one wheel, in particular an omnidirectional wheel.

[0035] Particularly preferably, the contact element, in particular the wheel, can be drivable. Generally, the contact element can be motor-driven and / or adjustable. This allows the position of the contact element to be adapted to the surface to be contacted.

[0036] The pose of the end effector, in particular the tool, relative to the work site where the construction work is to be performed can thus be finely adjusted by appropriately moving the contact element, in particular the wheel. In particular, the contact element can thus form the actuating device or at least part of the actuating device. The pose can thus also be adjusted at least two-dimensionally as soon as the construction robot contacts the work site, for example, the ceiling, with its contact element.

[0037] The parallel manipulator can have at least one return element and / or a damping element. Vibrations or minor movements of the mobile platform can thus be dampened. The end effector, and in particular the tool, can thus be further stabilized relative to the mobile platform. The return element and / or the damping element can have a spring element.

[0038] The construction robot can be configured to perform marking work. For example, it can be configured to transfer CAD data, such as Building Information Model (BIM) data, to the construction site. In this case, a high degree of positioning accuracy, particularly of 5 mm or less, is particularly advantageous.

[0039] For this purpose, the tool can be and / or comprise a marking tool. The tool can, for example, comprise a pen, a spray device, an adhesive device, in particular for applying markings, or an engraving device.

[0040] Alternatively or additionally, the tool can be and / or comprise a drilling tool, a chiseling tool, a grinding tool, or a cutting tool, in particular a saw blade. Accordingly, the construction robot can be configured to drill, chisel, and / or cut.

[0041] The tool can be mounted on a lifting device. This allows the tool to be moved toward or away from the work area to be treated. In the case of a marking tool designed as a pen and used to mark positions on a ceiling, the pen can be placed on the ceiling at the location to be marked and removed again as needed.

[0042] The end effector can have an xy drive. The xy drive can be configured to move the tool and / or the lifting device two-dimensionally relative to the end effector. Thus, in the case of the tool designed as a marking tool, for example, smaller structures of a marking, such as a character to be written on the ceiling, can be transferred to the ceiling without the end effector having to be moved.

[0043] The end effector can be designed as an independent platform so that it can be combined with different types of mobile platforms.

[0044] The end effector, in particular together with the parallel manipulator and / or one or more of the features mentioned in connection with the end effector, can also be understood as an invention in itself.

[0045] The present framework also includes a calibration-free construction robot comprising a mobile platform and a manipulator movable relative to the mobile platform. The construction robot can have a sensor system, in particular an optical one, arranged and / or formed at least partially on the mobile platform, which is configured to determine a position and / or orientation of the manipulator, in particular of a tool arranged on the manipulator, relative to the mobile platform. Part of the sensor system can be arranged and / or formed on the manipulator. The sensor system can comprise a camera and a localization marker. The localization marker is preferably arranged in the field of view of the camera.

[0046] The manipulator may, for example, have a multi-axis arm. Alternatively or additionally, in particular analogous to the above, it may be and / or comprise a parallel manipulator.

[0047] One advantage of the calibration-free construction robot is that it can determine the position and / or orientation of the end effector and / or tool relative to the mobile platform independently and independently of the mechanical properties of the manipulator. If the manipulator is replaced, no calibration, or at most fewer calibration measures, are required to precisely control the tool to the desired positions using the replaced manipulator. Instead, the manipulator can be moved, for example in a feedback loop, and the reached position of the end effector and / or tool relative to the mobile platform can be determined using the sensors. If the reached position deviates from a target position, the manipulator can perform a corrective movement repeatedly until the target position is reached.

[0048] The calibration-free construction robot can also have one or more of the features of a construction robot described above and / or below.

[0049] Furthermore, the present framework also includes the use of a sensor system, in particular an optical one, together with a construction robot comprising a mobile platform and a manipulator, wherein a position and / or orientation of the manipulator and / or a tool arranged on the manipulator relative to the mobile platform is determined with the aid of the sensor system.

[0050] During use, the sensor system and / or the construction robot may also have one or more of the features of a construction robot or sensor system described above and / or below.

[0051] Further features and advantages of the invention will become apparent from the following detailed description of exemplary embodiments of the invention, based on the figures of the drawing, which illustrate details essential to the invention, and from the claims. The features shown therein are not necessarily to scale and are presented in such a way that the special features of the invention can be clearly seen. The various features can be implemented individually or in combinations in variants of the invention.

[0052] The schematic drawing shows embodiments of the invention and explains them in more detail in the following description.

[0053] They show:

[0054] Fig. 1 a construction robot performing a construction task on a ceiling,

[0055] Fig. 2 an end effector platform of the construction robot, and

[0056] Fig. 3 a localization marking.

[0057] In the following description of the figures, the same reference numerals are used for identical or functionally corresponding elements to facilitate understanding of the invention.

[0058] Fig. 1 shows a construction robot 10 performing a construction task on a ceiling 100, i.e., a construction site object of a building under construction, in particular on a construction site located within the building. The construction task consists of marking the underside of the ceiling 100 according to available CAD planning data.

[0059] The construction robot 10 is designed as a drone, i.e., an unmanned aerial vehicle. It has a mobile platform 12 in the form of a hexacopter. An end-effector platform 14 is arranged on the mobile platform 12.

[0060] Fig. 2 shows the end effector platform 14 in a perspective view from the side. The end effector platform 14 includes an end effector 16. The end effector 16 is connected to the

[0061] Parallel manipulator 18 of the construction robot 10 connected to the mobile platform 12.

[0062] The construction robot 10 is configured to mark the ceiling 100 according to CAD data transmitted to the construction robot 10. For this purpose, the end effector 16 has a marking pen 20.

[0063] The marking pin 20 is arranged on a lifting device 22. Thus, in the position of the construction robot 10 shown in Fig. 1, the marking pin 20 can be moved toward and / or away from the ceiling 100, in particular without having to move the end effector platform 14 as a whole. This movement option is symbolized in Fig. 2 with a double arrow.

[0064] The marking pen 20 is designed as a colored pen, so that it can apply a colored mark to the ceiling 100 as soon as it touches the ceiling 100. To enable adequate paint application and to protect the marking pen 20 from excessive mechanical stress, the marking pen 20 can be arranged on the lifting device 22 in a resilient manner, for example by means of a foam material and / or a metal element. The marking pen 20 thus represents a marking tool that is received in a tool holder (not visible in the illustration according to Fig. 2), which in turn is arranged on the lifting device 22.

[0065] The end effector 16 further comprises three contact elements 24. The contact elements 24 are designed as wheels, in particular as omnidirectional wheels. As can be seen in particular from Fig. 1, the contact elements 24 contact the ceiling 100 during the execution of the construction task, i.e., during the marking of the ceiling 100. They can each be individually driven by motors 26. Thus, the end effector 16 can be moved along the ceiling 100 (Fig. 1) at least along two dimensions with the aid of the motor-driven contact elements 24, i.e., in this embodiment, with the aid of the omnidirectional wheels.

[0066] The parallel manipulator 18 is designed as a hexapod. It has six support arms 28. In this exemplary embodiment, the support arms 28 are not driven, but are rotatably mounted on bearing points of the end effector 16, as well as on bearing points of a fastening device 30 located beneath the end effector 16. Thus, the end effector 16 is movable relative to the fastening device 30, in particular with at least six degrees of freedom, but is nevertheless supported by the support arms 28. The parallel manipulator 18 is thus designed as a passive system.

[0067] The support arms 28 are designed as shock absorbers, in particular fluid-damped ones. For damping, they have a fluid-filled piston, in particular one filled with water, and spring elements arranged on the outside. The pistons, together with the respective spring elements, thus form damping elements. In addition, the spring elements ensure automatic return to the rest position when the end effector 16 is deflected relative to the fastening device 30 from a rest position. The spring hardness of the support arms 28 can be adjusted such that they are retracted in the rest position to approximately half the total length of the support arms 28 due to the dead weight of the end effector 16 or, alternatively, due to the dead weight of the end effector 16 plus an expected additional load force, for example, 15 N.Starting from the rest position, they can be configured so that the end effector 16 can be moved sufficiently far, for example by 2 to 4 cm in each of the x and y directions of a plane parallel to the end effector 16.

[0068] The support arms 28 are arranged such that the end effector platform 14 is in a stable state in the rest position. In particular, the support arms 28 are arranged such that the end effector 16 does not tilt to one side on its own.

[0069] Positions and / or locations for the support arms 28 suitable for such a stable rest position can be found by creating a total energy balance of the arrangement, in particular comprising a potential energy of the end effector and, if applicable, of the support arms 28 as a function of its or their position and / or location, as well as a tension energy of the spring elements of the support arms 28, and by searching for a global minimum, but at least a local minimum, of the total energy as a function of the positioning and / or orientation of the support arms 28.

[0070] The fastening device 30 serves to fasten the end effector platform 14 to the mobile platform 12 (see Fig. 1). The fastening can be detachable, so that the end effector platform 14 can also be subsequently mounted on other mobile platforms, for example, octacopters or on a ground-based mobile platform, for example, a wheeled and / or tracked chassis. The fastening device 30 forms a lower level below the end effector 16. It has a lighting unit 32 and a camera 34. The lighting unit 32 and the camera 34 are directed upwards, i.e., toward the underside of the end effector 16. A localization marking 36 is located on the underside of the end effector 16, particularly in the field of view of the camera 34.

[0071] Fig. 3 shows an example of an image of the localization marking 36 recorded by the camera 34. The localization marking 36 has a checkerboard-like pattern of registration marks, for example in the form of ArUco markings.

[0072] A control unit 38, shown schematically in Fig. 2, is configured to evaluate images taken by the camera 34 and to determine a position and / or orientation of the end effector 16 relative to the fastening device 30 by image processing from the type, size, orientation and / or position of the registration marks.

[0073] Furthermore, a reflection element 40 is arranged on the fastening device 30, which is designed to be detected, for example, by a total station located in particular outside the construction robot 10, so that the position and / or orientation of the reflection element 40 and thus the position and / or orientation of the fastening device 30 can be determined.

[0074] The control unit 38 can be configured to receive position and / or attitude data from such a total station and, in conjunction with the determined relative position and / or attitude of the end effector 16 relative to the fastening device 30, to determine an absolute position and / or attitude of the end effector 16 and thus also taking into account the position of the lifting device 22, a position and / or attitude of the marking pin 20 relative to the total station, to the ceiling 100 and / or to another stationary reference system of the construction site.

[0075] The control unit 38 can further be configured to control the contact elements 24, i.e., in this embodiment, the wheels, depending on the determined position and / or orientation of the marking pin 20. This allows, for example, vibrations or other minor positional changes of the mobile platform 12 to be compensated for. The control unit 38 can be configured as a microcontroller for this purpose. It can, in particular, comprise a microprocessor and program code executable on the microprocessor and stored in a memory unit of the control unit 38.

[0076] In order to achieve the greatest possible autonomy of the end effector platform 14, the end effector platform 14 can also have an energy source independent of the mobile platform 12, for example a rechargeable battery.

[0077] The control unit 38, the camera 34 and the localization marking 36 thus form a sensor system that is configured to detect a pose of the end effector 16 relative to the mobile platform 12.

[0078] The end effector 16 may further comprise an acceleration sensor 42, for example, measuring three-dimensionally (shown only schematically in Fig. 2). Thus, accelerations of the end effector 16 can be measured. Using the measured accelerations, the determination of the position and / or orientation of the end effector 16 and thus of the marking pen 20 can be further improved, particularly by the control unit 38.

[0079] List of reference symbols

[0080] 10 construction robots

[0081] 12 Mobile Platform

[0082] 14 E nd eff e ctor- PI attf o rm

[0083] 16 End effector

[0084] 18 Parallel manipulator

[0085] 20 marker pens

[0086] 22 Lifting device

[0087] 24 contact element

[0088] 26 Engine

[0089] 28 Support arm

[0090] 30 Fastening device

[0091] 32 Lighting

[0092] 34 Camera

[0093] 36 Localization marking

[0094] 38 Control unit

[0095] 40 reflection element

[0096] 42 Accelerometer

[0097] 100 blanket

Claims

Patent claims 1. Construction robot (10) for carrying out construction work on a construction site object, comprising - a mobile platform (12), - an end effector (16), wherein the end effector (16) has at least one tool or tool holder for receiving a tool, and - a parallel manipulator (18) wherein the end effector (16) and the mobile platform (12) are connected to each other via the parallel manipulator (18), - wherein the end effector (16) has at least one contact element (24) which is configured to contact the construction site object to be worked on during construction work, and - a sensor system for detecting a pose of the end effector (16) relative to the mobile platform (12).

2. Construction robot according to the preceding claim, characterized in that the sensor system comprises an image acquisition unit.

3. Construction robot according to one of the preceding claims, characterized in that the end effector (16) and / or the parallel manipulator (18) has a localization marking, for example in the form of an AruCo marking.

4. Construction robot according to one of the preceding claims, characterized in that the localization marker is arranged at least partially, preferably completely, in a field of view of the image acquisition unit.

5. Construction robot according to one of the preceding claims, characterized in that the parallel manipulator (18) is designed as a passive system.

6. Construction robot according to one of the preceding claims, characterized in that the parallel manipulator (18) has at least three, preferably at least six, degrees of freedom.

7. Construction robot according to one of the preceding claims, characterized in that the parallel manipulator is configured to automatically return to the rest position from a rest position, in particular by gravity, when the end effector (16) is slightly deflected relative to the mobile platform (12).

8. Construction robot according to one of the preceding claims, characterized in that the mobile platform (12) is a flight platform.

9. Construction robot according to one of the preceding claims, characterized in that the parallel manipulator (18) is designed as a hexapod.

10. Construction robot according to one of the preceding claims, characterized in that the construction robot (10) has an acceleration sensor (42), in particular wherein the acceleration sensor (42) is formed on the end effector (16).

11. Construction robot according to one of the preceding claims, characterized in that the construction robot (10), in particular the end effector (16) and / or the mobile platform (12), has a position measuring system for determining a pose of the construction robot (10) relative to an environment, in particular a construction site, and / or is equipped to be detected by such a position measuring system for determining its position and / or orientation.

12. Construction robot according to one of the preceding claims, characterized in that the position measuring system comprises a laser distance meter and / or a total station.

13. Construction robot according to one of the preceding claims, characterized in that the contact element (24) has at least one wheel, in particular an omnidirectional wheel.

14. Construction robot according to one of the preceding claims, characterized in that the contact element (24) is motor-driven.

15. Construction robot according to one of the preceding claims, characterized in that the parallel manipulator (18) has at least one restoring element and / or a damping element. Construction robot according to one of the preceding claims, characterized in that the tool is and / or comprises a marking tool, a drilling tool, a chiseling tool, a grinding tool and / or a cutting tool, in particular a saw blade.

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