Stability of the mobile manipulator controlled by the external stabilizing device
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ABB (SCHWEIZ) AG
- Filing Date
- 2023-11-08
- Publication Date
- 2026-05-29
AI Technical Summary
Mobile manipulators operating in confined spaces are prone to tipping over, and the time required to perform tasks is relatively long. Existing technologies struggle to effectively stabilize robots to ensure their stability during navigation and the execution of pick-up and place-down tasks.
By combining an external stabilization device with a motion manipulator, the current and desired zero-movement point (ZMP) trajectory is determined, and the configuration of the manipulator is adjusted using the external stabilization device to keep the ZMP within the supporting polygon. The external stabilization device is controlled by a control device to achieve stability.
It effectively prevents the mobile controller from tipping over, ensuring stability and efficient movement during task execution, reducing floor space, and improving task execution efficiency.
Smart Images
Figure CN122121987A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a method for controlling a mobile manipulator, a mobile manipulator, a computer program product, and a computer-readable medium. Background Technology
[0002] In recent years, the automation industry has increasingly focused on automation applications in the life sciences and pharmaceutical fields. These applications typically consist of a combination of transport tasks in a laboratory environment and pick-and-place tasks on different workbenches. One type of robot proposed to meet these needs is the mobile manipulator. It combines a mobile base with an attached manipulator. Due to the limited space in laboratory environments, the size requirements for these robots are becoming increasingly stringent. In particular, the robot's footprint is a focus of optimization. Common manipulators often include heavy and large bases, which can be disadvantageous when the robot operates in confined spaces. In addition to the robot's size, the total time required for the robot to perform a task must also be continuously reduced. This requirement results in higher acceleration of the mobile base during navigation and when performing pick-and-place tasks. The challenge posed by these requirements is ensuring the robot remains stable, such as preventing it from tipping over. Stability issues can arise with higher dynamic forces, thus increasing the challenge of ensuring robot stability.
[0003] Therefore, advanced methods are needed to prevent instability in mobile manipulators. Summary of the Invention
[0004] This objective is achieved by the invention according to the independent claims. Preferred embodiments of the invention are provided in the dependent claims, the specification, and the drawings.
[0005] The present invention relates to a method for controlling a mobile manipulator, the mobile manipulator including a manipulator base and at least one manipulator arm.
[0006] The method includes the following steps: determining the current configuration of the mobile manipulator, which includes the manipulator arm configuration and the manipulator base configuration.
[0007] The method includes the following steps: determining the desired movement trajectory of the motion manipulator.
[0008] The method includes the following steps: determining the current zero-movement point ZMP trajectory based on the current configuration of the mobile manipulator and the desired movement trajectory, the current ZMP trajectory including the position of one or more current ZMPs of the mobile manipulator.
[0009] The method includes the following steps: determining the desired ZMP trajectory of the moving manipulator, wherein each ZMP is located within a supporting polygon of the manipulator base.
[0010] The method includes the following steps: adjusting the motion manipulator so that the current ZMP trajectory corresponds to the desired ZMP trajectory.
[0011] In the method according to the invention, the mobile manipulator further includes at least one external stabilizing device, and the step of adjusting the mobile manipulator includes the step of supporting the mobile manipulator by the external stabilizing device.
[0012] Therefore, a flexible method can be provided for stabilizing a mobile manipulator using an external stabilizing device, ensuring that the manipulator remains stable and does not tip over. Control of the external stabilizing device can be performed by a corresponding control unit of the mobile manipulator. The control unit may include a corresponding computing device adapted to control the movement of the external stabilizing device based on corresponding input parameters, such that the current ZMP trajectory corresponds to the desired ZMP trajectory. For example, the manipulator arm can be extended as far as possible to have the maximum working range. Depending on the weight of the manipulator arm and / or the weight and motion of the object positioned at the tool center point (TCP) at the distal end of the manipulator arm, the mobile manipulator can become unstable and may therefore tip over. In such cases, the current ZMP trajectory of the mobile manipulator lies outside the supporting polygon. The control method of the present invention can be particularly useful for stabilizing mobile manipulators performing stationary pick-and-place tasks.
[0013] A mobile manipulator can be any kind of mobile robot. In this context, a "mobile" or "movable" manipulator can be understood as one that enables the manipulator to occupy different positions or locations on the ground. The position of the mobile manipulator can change accordingly. For example, a mobile manipulator can move on its own or, through appropriate means, move from a starting point to a destination via a predetermined specific path.
[0014] A manipulator arm can be any type of robotic arm. It may comprise multiple elements linked together and connected to a movable base to form a kinematic chain. The links of such a manipulator arm can be connected via corresponding joints, allowing, for example, rotational motion or linear translation. However, it should be understood that a manipulator arm may also consist only of rigid elements linked to a manipulator base. The manipulator arm can be programmable to allow for corresponding movements to perform different tasks. More than one manipulator arm may also be configured.
[0015] An external stabilizing device can be an element that allows for an increase in the size of the supporting polygon by contacting the environment of the moving manipulator. An external stabilizing device may include multiple elements linked to each other and to the moving base to form a kinematic chain. The external stabilizing device may take the form of a telescopic arm attached to the moving manipulator. The links of the external stabilizing device may be connected by corresponding joints, thereby allowing, for example, rotational motion or linear translation. However, it should be understood that an external stabilizing device may also consist only of rigid elements linked to the manipulator base. The external stabilizing device may be programmable to allow for the execution of corresponding movements. More than one external stabilizing device may also be provided.
[0016] The manipulator base can substantially define the core body of the mobile manipulator, to which the manipulator arm and / or external stabilization device can be attached. The manipulator base can house corresponding propulsion or control devices, such as power supplies, one or more motors, and / or computing devices, which can be enclosed by a housing to protect the internally arranged mobile manipulator components from negative influences such as dust and moisture. The manipulator base can define a support polygon, which can be extended by the external stabilization device. The support polygon can be the surface area on which the mobile manipulator is supported or carried on the ground. The support polygon can include three, four, or more sides, or can have a circular, elliptical, or any other two-dimensional shape.
[0017] The current configuration of the motion manipulator may include information about the extension and / or weight of its various parts. For example, the current configuration may include information about the center of gravity of each component and / or the entire motion manipulator. The center of gravity of the motion manipulator may include the mass and dimensions of the entire motion manipulator, or it may include only the mass and dimensions of its individual parts. For example, this may be one or more of the largest parts that have the greatest influence on the location of the center of gravity of the motion manipulator.
[0018] The manipulator arm configuration may include the extension or orientation of the manipulator arm relative to the manipulator base, such as the rotation angle or degree of extension of the manipulator arm, and information about the weight or item carried by the manipulator arm. The manipulator base configuration may include information about the weight or dimensions of the manipulator base, such as the dimensions of the lower base surface of the manipulator base (which may form a supporting polygon). Any suitable parameters regarding the center of mass of the moving manipulator may be included.
[0019] The position where the manipulator arm and / or external stabilization device is attached to the manipulator base can be fixed or variable. The manipulator arm and / or external stabilization device can be positioned on any desired side of the manipulator base, such as the top, front, or rear side, or on one of the lateral sides of the manipulator. The manipulator arm configuration can include different positions and / or orientations of the manipulator arm in space, such as arm posture. The manipulator arm configuration can include information about the rotational position of the manipulator arm or the extent of extension of the manipulator arm, such as extension beyond the manipulator base. The manipulator base configuration can accordingly include the spatial extension of the manipulator base and its weight or weight distribution.
[0020] The desired movement trajectory can be a path or route that a mobile manipulator can take on the ground. Therefore, the desired movement trajectory can be provided in a substantially horizontal two-dimensional plane. The mobile manipulator can move along the desired movement trajectory from a starting position to an intermediate or ending position on the ground. The desired movement trajectory can be based on one or more tasks that the mobile manipulator should perform, such as picking up an item at a first position and placing the item at a second position. Alternatively, the desired movement trajectory can be based on the movement of a manipulator arm performing a specific task, picking up an item at a first position and placing the item at the same position. The movement trajectory can include one or more linear or curved movements, or any other arbitrary geometric movement, such as movement on the ground between a starting position and an ending position. The desired movement trajectory can include intermediate positions where the mobile manipulator can change its direction of movement. For example, the mobile manipulator can pick up an item at a starting position and move along the desired movement trajectory toward an ending position to place the item at that ending position. The mobile manipulator can then proceed to a third point, with or without picking up the same or different items, and / or can return to its starting position.
[0021] ZMP can be understood as a point where the contact reaction force between the manipulator and the ground produces no torque in the horizontal direction (i.e., in the plane in which the manipulator is moving). This can be a direction in a plane substantially perpendicular to the direction of gravity. In common notation, the plane in which the manipulator is moving can be extended in the xy direction, while the direction of gravity is in the z direction. ZMP can be considered as a horizontal torque. M x and M yThe point where the sum of the points is zero. In other words, the ZMP can be defined as a reference point in the contact plane between the robot and the ground, at which the horizontal component of the contact torque disappears. The ZMP of a mobile manipulator can depend on the manipulator arm configuration, the manipulator base configuration (e.g., the extension of the support polygon), and the desired movement trajectory. One or more ZMPs can be determined or predicted for a mobile manipulator. In this disclosure, determination can also be understood as prediction. Any ZMP can depend on the configuration of the mobile base and the manipulator arm, including, for example, the weight and spatial extension of the components and their respective arrangement relative to each other.
[0022] Based on the current configuration of the mobile manipulator, the current ZMP trajectory can be determined or predicted. As the mobile manipulator moves along the desired trajectory, the current ZMP trajectory can correspond to one or more predicted ZMP positions of the mobile manipulator. The mobile manipulator can be considered stable when its predicted current ZMP is located within a supporting polygon. If one or more predicted current ZMPs of the mobile manipulator are arranged within the supporting polygon, the mobile manipulator can be stable, preventing tipping during movement along the desired trajectory. Therefore, in the method of the present invention, the mobile manipulator can preferably be configured such that its ZMP is located within a supporting polygon, thereby allowing stable movement or stationary position.
[0023] Therefore, understanding the desired trajectory of the mobile manipulator and considering its configuration (e.g., based on arm configuration) allows for the determination or prediction of a desired ZMP trajectory that enables stable movement of the mobile manipulator as it moves along that trajectory or as the manipulator arm extends stably to pick up and place heavy objects. Stable movement of the mobile manipulator can be achieved if it will move along the desired trajectory and its ZMP corresponds to or is sufficiently close to the desired ZMP trajectory.
[0024] Therefore, the manipulator can be adjusted accordingly so that the current ZMP trajectory corresponds to or approximates the desired ZMP trajectory, thereby achieving stable movement of the manipulator. This adjustment can be made before or during movement. Different adjustments can be made to the manipulator to achieve a stable configuration for different segments of the trajectory. Similar adjustments can be performed when the manipulator is stationary and only the manipulator arm is moving. For example, if the ZMP will be outside or too far from the desired ZMP trajectory, the manipulator may therefore become unstable during movement of the manipulator base and / or manipulator arm.
[0025] In the method of this invention, a control strategy based on the ZMP criterion can be formulated. The desired ZMP trajectory can be based on the current motion of the moving base. The desired ZMP trajectory needs to comply with the ZMP criterion and must be located inside the supporting polygon. Its exact position within the polygon is not restricted and can be used for other optimization criteria, such as those related to energy optimality. Using the desired ZMP trajectory as a reference trajectory, the control problem according to the invention can be established. Therefore, the control function... This method can be used to minimize the deviation between the actual or current ZMP trajectory and the desired ZMP trajectory. It allows for appropriate support of the motion manipulator via corresponding control from external stabilization devices.
[0026] In a preferred embodiment, the manipulator base includes one or more contact elements configured to contact a movable manipulator on a ground surface, wherein the contact elements are preferably formed of wheels.
[0027] Therefore, stable standing on the ground at the base of the mobile manipulator can be achieved during movement or stopping. Providing wheels allows the mobile manipulator to be easily guided along the ground in one or more desired directions. One or more wheels can be actively steered by corresponding control and propulsion mechanisms of the mobile manipulator, or can be passively rotated. The invention is not limited to wheels, but may also include any type of steerable or non-steerable element that allows movement of the mobile manipulator on the ground.
[0028] In a preferred embodiment, the manipulator base includes at least three contact elements, wherein a support polygon is defined by an area formed between the contact elements, and wherein when the manipulator is stabilized by an external stabilizing device, the support polygon is further defined by contact points of the external stabilizing device, wherein the ZMP is adjusted to be located within the support polygon of the manipulator.
[0029] Therefore, the support polygon can be defined by the area between contact elements that contact the ground, and also by the contact points of the external stabilizing device when the mobile manipulator is stabilized by it. The contact points can be the points where the external stabilizing device contacts one or more supporting surfaces (e.g., a table, wall, or any other supporting element) in the mobile manipulator's environment. This contact can correspondingly stabilize the mobile manipulator. Therefore, to achieve a stable state for the mobile manipulator, the support polygon can be enlarged compared to the case without an external stabilizing device. The ZMP can be adjusted accordingly to lie within the support polygon to allow for stable movement or standing of the mobile manipulator during operation.
[0030] In a preferred embodiment, the external stabilization device includes at least one telescopic support arm that can be activated or deactivated based on the following steps: determining the ZMP of the moving manipulator during manipulator movement, deactivating the telescopic support arm when the ZMP of the moving manipulator is determined to be within the support polygon, and activating the telescopic support arm when the ZMP of the moving manipulator is determined to be outside the support polygon.
[0031] Therefore, a flexible support method for a mobile manipulator can be provided, which allows for stable movement of the manipulator as needed. Activation or deactivation may include the extension or retraction of a telescopic support arm. The telescopic support arm may include multiple interconnected telescopic support arm elements that can move relative to each other in a manner similar to a telescopic arm. The movement of the telescopic support arm elements can therefore be substantially along the extension axis. The telescopic arm may be hinged to the manipulator base at its proximal end and may provide contact with an environmental support surface at its distal end. The extension and movement of the telescopic support arm can be determined accordingly by corresponding sensor devices and control devices of the mobile manipulator, including corresponding motors for activating and / or deactivating the telescopic support arm.
[0032] In a preferred embodiment, the external stabilizing device includes at least one support wheel, wherein the support wheel can be activated or deactivated, wherein when activated, the support wheel contacts the ground and increases the support polygon of the moving manipulator.
[0033] Therefore, an additional or alternative stabilization option can be provided. The support wheel can resemble a propulsion or drive wheel that moves the moving component above the ground. However, the support wheel can also be configured in entirely different ways. The support wheel can be actively steered or passively rotated. The support wheel can be linked to the mobile manipulator base via a support wheel axle. The support wheel axle can be formed stably enough to allow stable support for the mobile manipulator and can be formed from a single rigid element or multiple interconnected elements that can operate, for example, in a manner similar to a telescopic boom. More than one support wheel can also be provided.
[0034] In a preferred embodiment, control of the mobile manipulator includes the following steps: controlling the mobile manipulator according to one or more stabilization methods for adjusting the mobile manipulator during movement, and controlling the telescopic support arm and / or controlling the support wheel.
[0035] Therefore, a combined method for stabilizing a moving manipulator can be provided. Alternatively, stabilization control methods can be based on steps of adjusting the center of mass of the moving manipulator, including adjusting the manipulator arm configuration and / or adjusting the variable mass element of the moving manipulator.
[0036] Alternatively, another stabilization control method can be based on adjusting the movement of the manipulator, including dynamic manipulator arm movement, which can be controlled by the following first control function: ,
[0037] in" "It could be the desired ZMP trajectory;" "This could be an actual ZMP trajectory;" "It could be time;" "It can be the joint state of the manipulator arm (acceleration, velocity, and position); while" "It can be the deviation between the actual ZMP trajectory and the expected ZMP trajectory."
[0038] Alternatively, another stabilization control method can be based on adjusting the movement manipulator steps, which is based on the following second control or planning function: , Among them, the joint acceleration of the manipulator arm "It can be preferably used as the input variable of the second control function."
[0039] Alternatively, another stabilization control method can be based on adjusting the movement of the manipulator, including dynamic manipulator arm movement, which can be controlled by the following first control function: ,
[0040] in" "It can be the rotational position, rotational speed, and rotational acceleration of the manipulator base."
[0041] Alternatively, another stabilization control method can be based on adjusting the movement manipulator steps, which is based on the following second control or planning function: .
[0042] Therefore, one or more of the above-described stabilization control methods can be applied, and for example, if the above methods are insufficient to provide stable movement of the moving manipulator, the telescopic support arm and / or support wheel can be controlled accordingly to further stabilize the moving manipulator.
[0043] In a preferred embodiment, the support wheel can be activated to extend from the manipulator base, thereby contacting the ground and increasing the support polygon of the moving manipulator.
[0044] Therefore, flexible adjustment of the support polygon can be provided, allowing for corresponding control of the moving manipulator to achieve stable movement. Activation may include extending the support wheel away from the manipulator base to increase the support surface or support polygon of the moving manipulator. Activation may include extending the support wheel axle so that the contact between the support wheel and the ground can be appropriately spaced from the manipulator base. Similarly, when it can be determined that no additional support is needed, the support wheel can be retracted accordingly. This activation may include determining the distance between the support wheel and the manipulator base required for stabilizing the moving manipulator, and can accordingly control the support wheel to extend to that distance and contact the ground.
[0045] In a preferred embodiment, the motion manipulator includes a plurality of support wheels, and a selected support wheel is selected based on the following steps: applying one or more stabilization methods, determining whether the actual ZMP trajectory of the motion manipulator corresponds to a desired ZMP trajectory, and when the actual ZMP trajectory of the motion manipulator does not correspond to the desired ZMP trajectory, the method further includes the following steps: determining at least one support wheel suitable for increasing the support polygon such that the actual ZMP trajectory of the motion manipulator corresponds to the desired ZMP trajectory, and activating the selected support wheel from the plurality of support wheels.
[0046] Therefore, a customized support can be provided for the mobile manipulator, which can utilize different support wheels from multiple support rollers. Thus, support wheels that are unsuitable or less suitable than the selected support wheels can be deactivated. This prevents the mobile manipulator from excessively increasing its footprint.
[0047] The selection of a single support wheel can be based on the spatial constraints of the manipulator's environment. Alternatively, the selection can be based on one or more optimization criteria, such as simply increasing the support polygon until the requirement for stable movement of the manipulator is met. More than one support wheel can also be identified and activated.
[0048] In a preferred embodiment, activating the support wheel includes determining and setting a specific distance from which the support wheel extends from the manipulator base.
[0049] Therefore, when stable movement of the mobile manipulator can be achieved, unnecessary spacing of the support wheels can be prevented. The appropriate distance to be set can be determined and set by the corresponding determination and control device of the mobile manipulator. This can include determining the degree of instability of the movable manipulator based on the current and desired ZMP trajectory.
[0050] The present invention also relates to a mobile manipulator, which includes a manipulator base, at least one manipulator arm, and a control device suitable for controlling the mobile manipulator according to the method of the present invention.
[0051] Therefore, a mobile manipulator can be provided, wherein the mobile manipulator can be controlled accordingly to achieve increased stability. It should be noted that the above explanations of certain elements or advantages described with respect to the method of controlling the mobile manipulator of this disclosure apply accordingly to the mobile manipulator described herein. Thus, a mobile manipulator that is particularly stable in motion or at rest can be provided. Control devices can be arranged at the mobile manipulator, or at least partially arranged outside the mobile manipulator and away from it. The control devices may include suitable computing and control mechanisms for controlling any element of the mobile manipulator, such as the orientation or extension of the manipulator arm, propulsion speed, wheel acceleration or steering, and / or activation or deactivation of one or more external stabilizing devices. The control devices may include corresponding sensors or detectors to determine the current position or movement of the corresponding element. The determination of the configuration of the mobile manipulator and / or the determination or prediction of any parameters (such as the current configuration of the mobile manipulator, desired trajectory, determination of ZMP, current or desired ZMP trajectory, etc.) can be performed by a corresponding computing device, which may or may not be part of the control mechanism of the mobile manipulator. A mobile manipulator may include one or more tools arranged at the distal end of a manipulator arm to perform corresponding manipulatory actions, such as picking up and lifting items, and transporting and placing said items in different locations.
[0052] In a preferred embodiment, the manipulator base includes at least one telescopic support arm, wherein the telescopic support arm is controllable according to the method of the invention.
[0053] In a preferred embodiment, the manipulator base includes at least one support wheel, wherein the support wheel is controllable according to the method of the invention.
[0054] Therefore, a particularly stable moving manipulator can be achieved, which may include at least one telescopic support arm and / or at least one support wheel.
[0055] In a preferred embodiment, the mobile manipulator is an autonomous mobile manipulator robot, preferably comprising more than two steerable wheels.
[0056] Therefore, a flexible and reliable autonomous mobile manipulator is provided. This can include any type of manipulator robot, such as a mobile manipulator that can move above the ground. The robot's movement along the ground and the movement of the arms can be controlled fully or semi-automatically. At least two steerable wheels allow for particularly well-controlled movement above the ground. The wheels can be propelled or steered together or independently. The mobile manipulator robot can be an industrial robot, a logistics robot, a medical robot, a laboratory robot, or any other type of robot working in the corresponding industrial, logistics, medical, or laboratory environment, which can perform the desired task using one or more manipulator arms arranged on a mobile manipulator base.
[0057] The present invention also relates to a computer program product comprising instructions that, when executed by a computer, cause the computer to perform and / or control any of the methods disclosed herein.
[0058] The features of the system according to the invention can be implemented by appropriate digital or computing devices, which may include, for example, one or more computers, applications and / or networks.
[0059] This method can be implemented at least partially by a computer, and can be implemented in software or hardware, or in both software and hardware. Furthermore, the method can be executed by computer program instructions running on a device providing data processing capabilities.
[0060] The data processing device can be a suitable computing device, such as an electronic control module, or it can be a distributed computer system. The data processing device or computer may include one or more of the following: processor, memory, data interface, etc.
[0061] The present invention also relates to a computer-readable medium comprising instructions that, when executed by a computer, cause the computer to perform and / or control any of the methods disclosed herein.
[0062] Any of the computer, computer program product and / or computer-readable medium may be at least part of the mobile manipulator, or may be arranged away from the mobile manipulator.
[0063] The features and advantages outlined above in the context of systems and methods also apply to the computer program products and computer-readable media described herein. Similarly, any features and advantages relating to the methods of the invention apply accordingly to the mobile manipulators of the invention, and vice versa.
[0064] Computer programs can be stored / distributed on suitable media, such as optical storage media or solid-state media, provided with or as part of other hardware, but can also be distributed in other forms, such as via the Internet or other wired or wireless telecommunications systems.
[0065] Further features, examples, and advantages will become apparent from the following detailed description of preferred embodiments and accompanying drawings. Attached Figure Description
[0066] To better understand the invention and illustrate its practicality, accompanying drawings are provided and referenced below. It should be understood that the drawings represent exemplary embodiments only and therefore do not limit the scope of the claimed invention in any way. Elements with the same or similar functions are always indicated by the same reference numerals. No reference numerals in the claims should be construed as limiting the scope of the claims.
[0067] In the attached diagram,
[0068] Figure 1 A mobile manipulator according to an embodiment of the present invention is schematically illustrated;
[0069] Figure 2 The illustration schematically depicts different configurations of a motion manipulator according to an embodiment of the present invention;
[0070] Figure 3 This is a flowchart illustrating a method for controlling a mobile manipulator according to the present invention. Detailed Implementation
[0071] Figure 1A movable manipulator 1 according to the present invention is depicted. The movable manipulator 1 includes a manipulator base 3 and a manipulator arm 5 attached to the top side of the movable base 3. It should be understood that in different embodiments, more than one manipulator arm 5 may be provided, and the position of one or more manipulator arms 5 may vary; for example, the manipulator arm 5 may be located on the front, rear, or lateral side of the movable manipulator 1. The movable manipulator arm 5 is formed as a movable arm comprising a plurality of arm elements linked together to allow flexible movement and extension or retraction of the arm. However, it should be understood that in different environments, a rigid manipulator arm may also be provided, for example, consisting of only a single rigid arm element movably attached to the manipulator base 3. The manipulator arm 5 is hinged to the movable base 3 at its proximal end and includes a TCP 15 at its distal end. In the depicted embodiment, the TCP 15 is formed as a gripper to allow clamping and lifting of an external mass element or load 13. The manipulator base 3 includes a wheel-shaped contact element 9 that contacts the floor 11. Therefore, the manipulator 1 can move along the floor 11 along a predetermined trajectory. The manipulator 1 also includes an external stabilizing device in the form of a telescopic arm 17. In the depicted configuration, the telescopic arm 17 extends from the front of the manipulator base 3 and contacts the wall of the support platform, on which a mass element 13 is arranged.
[0072] Therefore, when the manipulator arm 5 picks up the mass element 13, the manipulator 1 is stabilized by the telescopic arm 17 and thus will not tip over. The orientation of the manipulator arm 5 and / or the telescopic arm 17 can be set and controlled by the control device 7 of the manipulator 1. In the depicted embodiment, the control device 7 is arranged at the manipulator 1. However, it should be understood that in different embodiments, the control device 7 may also be arranged at least partially outside or away from the manipulator 1. The control device 7 may include suitable sensing, calculation, and control devices for controlling the elements of the manipulator 1. This may include, for example, controlling the orientation of the manipulator arm 5 and / or the telescopic arm 17, or the propulsion speed, acceleration, and direction of movement of the wheel. Depending on the configuration of the manipulator arm 5 and / or the telescopic arm 17, the center of mass of the manipulator 1 changes. For example, in the depicted embodiment, due to the manipulator arm configuration, the center of mass of the manipulator 1 shifts to the right because the manipulator arm 5 extends beyond and away from the manipulator base 3. As described above, this can be counteracted by the contact of the telescopic arm 17, which correspondingly increases the support surface of the moving manipulator 1.
[0073] Furthermore, a computer program product 200 and a computer-readable medium 300 are shown, each including instructions that, when executed by the computer 100, cause the computer 100 to perform and / or control methods of any embodiment of the present invention, particularly as Figure 3The method is illustrated. In the depicted embodiments, computer 100, computer program product 200, and computer-readable medium 300 are depicted as external elements. However, it should be understood that in different embodiments, any one of computer 100, computer program product 200, and computer-readable medium 300 may be at least partially integrated into the mobile manipulator 1.
[0074] Figure 2 Different embodiments of the motion manipulator 1 are depicted. In this embodiment, a method for... Figure 1 The same components as the mobile manipulator 1 described in the embodiment are referenced here, except that an additional support wheel 19 is provided instead of the telescopic arm 17. The support wheel 19 can be activated when the mobile manipulator 1 becomes unstable, for example, due to a shift in the center of mass caused by the manipulator arm 5 extending to the right beyond the manipulator base 3. Therefore, the support polygon of the mobile manipulator 1 can be increased, and the mobile manipulator 1 can be stabilized accordingly. In sub-figure A), the support wheel 19 includes one degree of freedom, namely the extension of the wheel away from the manipulator base 3. Therefore, a corresponding distance from the support wheel 19 to the mobile manipulator 1 can be defined. In sub-figure B), the support wheel 19 includes two degrees of freedom, namely the extension of the wheel away from the manipulator base 3 and the height of the support wheel 19 relative to the ground 11. Therefore, the support wheel 19 can be adjusted accordingly in two dimensions.
[0075] Figure 3 A flowchart illustrating a method for controlling a mobile manipulator 1 according to an embodiment of the present invention is presented. In step S1 of the depicted embodiment, a desired movement trajectory of the mobile base 3 or the mobile manipulator 1 is determined. In step S2 of the depicted embodiment, a desired ZMP trajectory of the mobile base 3 or the mobile manipulator 1 is selected or determined based on the desired movement trajectory. As shown in step S3, optimization criteria can be introduced to improve the overall performance of the mobile manipulator 1. Such optimization criteria can be any suitable standard for optimizing the movement of the mobile manipulator, such as adopting the lowest possible acceleration or the highest possible speed or reducing the power consumption of the mobile manipulator 1. In step S4, the ZMP trajectory is used as input to define the motion of the mobile manipulator 1 to utilize redundant degrees of freedom. The degrees of freedom can be used accordingly to maintain the current ZMP trajectory of the mobile manipulator 1 on the desired ZMP trajectory of the mobile manipulator 1.
[0076] It should be understood that the method according to the present invention is not limited to the order of the method steps described above. On the contrary, the method steps may be provided in a different order, and one or more of the method steps described above may be removed as needed, or additional method steps may be added. Figure Labels 1. Mobile controller 3. Control base 5. Manipulator arm 7. Control device 9 Contact elements 11 Ground 13 Mass Components 15. Tool center point 17 Telescopic boom 19 Support wheels 100 computers 200 computer program products 300 Computer-readable media S1 to S4 Method Steps
Claims
1. A method for controlling a mobile manipulator (1), the mobile manipulator comprising a manipulator base (3) and at least one manipulator arm (5), the method comprising the steps of: Determine the current configuration of the mobile manipulator (1), the current configuration including the manipulator arm configuration and the manipulator base configuration. Determine the desired movement trajectory of the motion manipulator (1). Based on the current configuration of the mobile manipulator (1) and the desired movement trajectory, the current zero-movement point ZMP trajectory is determined, the current ZMP trajectory including the position of one or more current ZMPs of the mobile manipulator (1). Determine the desired ZMP trajectory of the mobile manipulator (1), wherein each ZMP lies within the support polygon of the manipulator base (3). Adjust the movement manipulator (1) so that the current ZMP trajectory corresponds to the desired ZMP trajectory. The mobile manipulator (1) further includes at least one external stabilizing device, and the step of adjusting the mobile manipulator (1) includes the step of supporting the mobile manipulator (1) by the external stabilizing device.
2. The method according to the preceding claims, The manipulator base (3) includes one or more contact elements (9) configured to contact the ground (11), and the mobile manipulator (1) is movable on the ground, wherein the contact elements (9) are preferably formed of wheels.
3. The method according to the preceding claims, The manipulator base (3) includes at least three contact elements, and the support polygon is defined by a region formed between the contact elements (9). When the moving manipulator (1) is stabilized by the external stabilizing device, the supporting polygon is further defined by the contact point of the external stabilizing device. The ZMP is adjusted to be located within the support polygon of the moving manipulator (1).
4. The method according to any one of the preceding claims, The external stabilizing device includes at least one telescopic support arm (17), which can be activated or deactivated based on the following steps: The ZMP of the moving manipulator (1) is determined during the movement of the manipulator arm (5). When it is determined that the ZMP of the moving manipulator (1) is located within the supporting polygon, the telescopic support arm (17) is deactivated, and When it is determined that the ZMP of the moving manipulator (1) is outside the supporting polygon, the telescopic support arm (17) is activated.
5. The method according to any one of the preceding claims, The external stabilizing device includes at least one support wheel (19), which can be activated or deactivated, wherein when activated, the support wheel (19) contacts the ground (11) and increases the support polygon of the moving manipulator (1).
6. The method according to the preceding claims, The control of the moving manipulator (1) includes the following steps: The movement manipulator (1) is controlled according to one or more stabilization methods used to adjust the movement manipulator (1) during the movement, and Control the telescopic support arm (17) and / or control the support wheel (19).
7. The method according to any one of claims 5 or 6, The support wheel (19) can be activated to extend from the manipulator base (3) to contact the ground and increase the support polygon of the mobile manipulator (1).
8. The method according to any one of the preceding claims, The moving manipulator (1) includes a plurality of support wheels (19), and a selected one of the plurality of support wheels (19) is selected based on the following steps: Apply one or more of the stabilization methods, Considering the selected stabilization method, determine whether the actual ZMP trajectory of the motion manipulator (1) corresponds to the desired ZMP trajectory, and When the actual ZMP trajectory of the moving manipulator (1) does not correspond to the expected ZMP trajectory, the method further includes the following steps: Determine at least one support wheel (19) suitable for increasing the support polygon such that the actual ZMP trajectory of the moving manipulator (1) corresponds to the desired ZMP trajectory. Activate the selected support wheel (19) from the plurality of support wheels (19).
9. The method according to any one of claims 5 to 8, The activation of the support wheel (19) includes the step of determining and setting a specific distance from which the support wheel (19) extends from the manipulator base (3).
10. A motion manipulator (1), comprising: The manipulator base (3), at least one manipulator arm (5), and at least one external stabilizing device, and A control device (7) adapted to control the motion manipulator (1) according to any one of claims 1 to 9.
11. The mobile manipulator (1) according to the preceding claims. The manipulator base (3) includes at least one telescopic support arm (17), which is controllable according to any one of claims 1 to 4.
12. The mobile manipulator (1) according to any one of claims 10 or 11. The manipulator base (3) includes at least one support wheel (19), wherein the support wheel (19) is controllable according to any one of claims 1 to 3 or 5 to 9.
13. The mobile manipulator (1) according to any one of claims 10 to 12. The mobile manipulator (1) is an autonomous mobile manipulator robot, preferably including more than two steerable wheels.
14. A computer program product (200) comprising instructions that, when executed by a computer (100), cause the computer (100) to perform and / or control the method according to any one of claims 1 to 9.
15. A computer-readable medium (300) comprising instructions that, when executed by a computer (100), cause the computer (100) to perform and / or control the method according to any one of claims 1 to 9.