Current-Based Impedance Control for Mobile Manipulators Without Force/Torque Sensors

Mobile manipulators, which combine a mobile platform with a robotic arm, are versatile robots that can be used for a variety of tasks like logistic pick-and-placing, manufacturing or assembly. Compliant control for mobile manipulators could improve the safety of the users sharing their workspace with these robots. The two general methods of...

Dynamic Optimization Fabrics for Motion Generation

Optimization fabrics are a geometric approach to real-time local motion generation, where motions are designed by the composition of several differential equations that exhibit a desired motion behavior. We generalize this framework to dynamic scenarios and nonholonomic robots and prove that fundamental properties can be conserved. We show...

Active Inference and Behavior Trees for Reactive Action Planning and Execution in Robotics

In this article, we propose a hybrid combination of active inference and behavior trees (BTs) for reactive action planning and execution in dynamic environments, showing how robotic tasks can be formulated as a free-energy minimization problem. The proposed approach allows handling partially observable initial states and improves the...

Knowledge-based Approach for Mobile Manipulation with Active Inference

Achieving human-like action planning requires profound reasoning and context-awareness capabilities. It is especially true for autonomous robotic mobile manipulation in dynamic environments. In the case of component failure, the autonomous robotic system requires reliable adaptation capabilities combined with a consistent understanding of the...

Local roadmap adaptation for mobile manipulators in incrementally changing environments

Mobile manipulators will be deployed in supermarkets for a large variety of tasks, for instance, for restocking products. The operation time of mobile manipulators can be reduced by generating coupled trajectories for the base and the robot's arm. When planning for high Degree of Freedom (DOF) robots, such as a mobile manipulator, in an obstacle...

Object Affordance Detection for Mobile Manipulation in Retail Environments

Modern retail stores are increasingly implementing automated systems with the aim of assisting both the customer and employee. Much research is conducted on robotic applications within such environments; one of these applications concerns deploying an autonomous mobile manipulator to assist humans in retail stores. Such a robot requires the...

Which position do I pick, if I don't know how to do the task?: A model to predict advantageous base poses for semi-autonomous robots.

In our aging society, the demand for care is increasing. Therefore, it is foreseen that robots will assist elderly. However, human assistance will often be required by the robot, which thus should be at a position advantageous for telemanipulation. For autonomous manipulation, methods have been developed that position a robot. But for...

Control of a quadrupedal manipulator using hierarchical inverse dynamics

Currently the prevalence of general purpose mobile robots with manipulation capabilities is still low, despite various applications of such systems such as: disaster response, payload delivery, and assistive/service tasks. A suitable design for such a robot would be that of a torque-controllable quadrupedal manipulator. Its capability for legged...

Robot Placement for Mobile Manipulation in Domestic Environments

The development of domestic mobile manipulators for unconstrained environments has driven significant research recently. Robot Care Systems has been pioneering in developing a prototype of a mobile manipulator for elderly care. It has a 6 degrees of freedom robotic arm mounted on their flagship robot LEA, a non-holonomic differential drive...

Multi-robot formation control and object transport in dynamic environments via constrained optimization

We present a constrained optimization method for multi-robot formation control in dynamic environments, where the robots adjust the parameters of the formation, such as size and three-dimensional orientation, to avoid collisions with static and moving obstacles, and to make progress towards their goal. We describe two variants of the...