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An unmanned ground vehicle (UGV) capable of executing controlled sliding and sharp turns without a significant decrease in velocity would have superior utility in field operations compared to a standard UGV. Such a vehicle would be better able to maneuver in tight corridors, avoid obstacles detected at short range, and minimize its time in dangerous situations. This paper presents theoretical analysis...
Special Automatic Guided Vehicles (AGVs) equipped with at least three omnidirectional wheels may be very useful tools in industrial applications because -in contrast to the Ackerman engines- their position and orientation with respect to the plane of operation can simultaneously be prescribed. So they have the ability for smart and precise navigation in a crowded environment. In the present constructions...
This paper presents a method to optimize motion from human motion for a humanoid robot with physical limits. Using the optimization scheme, objective functions incorporate spatial similarity with manipulability to preserve salient characteristics of trajectories, whereas constraints focus on representing angle, collision, velocity, and dynamic force as B-spline coefficients. To refine precision, in...
We present a methodology to steer the end effector of a robotic manipulator, which is constrained in terms of joint rates, on the surface within the workspace, to perform surface tasks. We develop smooth controllers for stabilizing the end effector to a point, and for tracking a trajectory on this surface, while respecting the input constraints, and the same time applying a specific force on it. We...
This paper treats the practical and challenging control problem of tracking a prescribed continuous trajectory for an autonomous underwater vehicle immersed in the presence of gravity, buoyancy, hydrodynamic and other uncertain forces and moments. These uncertain forces and moments are bounded and may be difficult to model accurately, but they act persistently or over long periods of time. The trajectory...
We provide Lyapunov-based control laws that stabilize relative equilibria in a model consisting of particles that travel on the surface of a rotating sphere in a time-invariant flowfield. These control laws are of interest because they have applications in planetary-scale mobile sensing networks in air and sea. A rotating sphere is introduced so that the particles are subject to the Coriolis effect...
In this paper, a control allocation approach is developed for energetic swarm control. This new approach allows sliding control of swarm temperature, swarm center position, and swarm potential energy. Since the sliding control problem is highly over-actuated, a control allocation optimization problem can be formulated and solved including input saturation constraints. Application to a group of wheeled...
In path planning, potential fields introduce force constraints to ensure curvature continuity of trajectories and thus to facilitate path-tracking design. In previous works, a path planning design by fractional (or generalized) repulsive potential has been developed to avoid fixed obstacles: danger level of each obstacle was characterized by the fractional order of differentiation, and a fractional...
In this paper, we propose a path planning method for nonholonomic multi-vehicle system in presence of moving obstacles. The objective is to find multiple fixed length paths for multiple vehicles with the following properties: (i) bounded curvature (ii) obstacle avoidant (iii) collision free. Our approach is based on polygonal approximation of a continuous curve. Using this idea, we formulate an arbitrarily...
In this paper we present a novel framework for computing the steady turning motion of a robotic fish undergoing periodic body and/or tail deformation. Taking the turning radius and the angular velocity as unknowns, we obtain the absolute motion trajectories of points on the ldquospinal columnrdquo of robotic fish by superimposing relative body/tail motions on the rigid body circular motion. The hydrodynamic...
The car transportation system, which termed as iCART (intelligent cooperative autonomous robot transporters), is developed for handling the car in the narrow space, substituting the parking and unmanning the transportation of cars. iCART is composed of two robots and these robots transport the car in coordination based on a leader-follower type distributed motion control algorithm. To avoid damaging...
A control approach for a class of underactuated vehicles with the objective of stabilizing reference trajectories either in velocity or position is proposed. The basic modeling assumption is that the vehicle is propulsed via a thrust force along a single body-fixed direction and that it has full torque actuation for attitude control (i.e. a typical actuation structure for aircrafts, vertical take-off...
We consider the problem of formation flight for a set of unmanned air vehicles (UAV) in a possible obstacle laden environment. A novel decentralized control design procedure is developed which guarantees collision and obstacle avoidance. The control design is based on a modified virtual leader-follower structure and a simple consensus protocol. Vehicle collision and obstacle avoidance is ensured by...
In path planning, potential fields introduce force constraints to ensure curvature continuity of trajectories and thus to facilitate path-tracking design. In previous works, a path planning design by fractional (or generalized) repulsive potential has been developed to avoid fixed obstacles: danger level of each obstacle was characterized by the fractional order of differentiation, and a fractional...
In this paper, an energetic swarm controller is developed that controls the swarm temperature, swarm centre position, and swarm potential energy. A sliding control approach is combined with a control allocation process to solve the overactuated control problem. The control allocation problem is solved using nonlinear programming software which allows the optimization problem to be solved with input...
The purpose of this study is to develop a methodology that enables a humanoid robot to imitate a whole body motion of a human. In the communication and interaction with a human being with motions and gestures, a humanoid robot needs not only to look like a human but to behave as a human does to make sure the meanings of motions and gestures. To act like a human, the humanoid robot has to imitate the...
Force compliant trajectory optimization is a term used here to describe a method of following an optimized path while interacting with an environment having only partial a priori knowledge. This can be used when the start and goal poses are fixed and what knowledge is available allows an initial path to be given. A robot traversing this path then senses the interaction force with the environment and...
This paper presents a method to generate motion from human motion for a humanoid robot with physical limits. The method focuses on representing constraints for angle, collision, velocity, and dynamic force as B-spline coefficients. The constraints can be applied for offline optimization and online filtering. For optimization, the objective function is responsible for mimicking human trainers, while...
This paper presents the mechanism of a human-friendly robot that is able to suppress collision forces. The human-friendly robot consists of a mobile base and a manipulator with a collision suppression mechanism. The mechanism is composed of an electromagnetic clutch and a rotary damper. If the manipulator collides with an object, the joint axis of the manipulator separates from the electromagnetic...
This paper describes an autonomous driving control algorithm based on skid steering for Robotic Vehicle with Articulated Suspension (RVAS). The driving control algorithm consists of four parts; speed controller for following a desired speed, trajectory tracking controller which computes a yaw moment input to track a desired trajectory, longitudinal tire force distribution which determines an optimal...
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