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In this paper, low-order Bézier motion primitives are proposed for motion planning in corridor-constrained spaces, which is illustrated on a warehouse application. The proposed primitives are easily computed for given requirements (initial and final position, orientation and curvature). A new parametrization of the motion primitives is provided which allows an intuitive geometric interpretation. The combined path constructed from these primitives has a minimal number of turns, as third-order Bezier curves are used. At the same time, the combined path has continuous curvature. A path planning approach is proposed that finds the optimal combination of primitives that results in a minimum travel time while satisfying constraints on velocity, acceleration, and free space. To illustrate the applicability of the approach, a comparison with a typical predefined warehouse path and an existing advanced optimisation planner is provided and evaluated.

The present paper aims to study the time-optimal path planning problem for a wheeled mobile robot in an obstacle-free environment with given initial and final configuration and considering constraints on maximal permissible velocity, acceleration, and jerk. The path consists of analytically derived constant acceleration and constant deceleration (CACD) motion primitives, which at the junctions also ensure smooth transitions of curvature, vehicle’s acceleration, and jerk. Smooth path planning is chosen to prevent instant changes of acceleration that improves the driving comfort, the tracking performance and lowers wear of actuators. Conducted experiments confirm that the proposed motion primitives form a feasible, time-optimal path under given dynamical constraints.

This work describes educational approaches in the field of wheeled mobile robotics. On the case of an engineering course in masters study programme, we present how the course has evolved in the past few years to the current format. Our tendency is to organize the course lectures and laboratory practice in a way that an appropriate balance between the traditional and contemporary inductive learning and teaching methodologies is achieved. We present application of various inductive teaching methodologies, such as simulation challenges, individual projects, multi-team projects and competition challenges, to the course. Several project examples from the course are given.

In this paper we present a visual-control algorithm for driving a mobile robot along the reference trajectory. The configuration of the system consists of a two-wheeled differentially driven mobile robot that is observed by an overhead camera, which can be placed at arbitrary, but reasonable, inclination with respect to the ground plane. The controller must be capable of generating appropriate tangential and angular control velocities for the trajectory-tracking problem, based on the information received about the robot position obtained in the image. To be able to track the position of the robot through a sequence of images in real-time, the robot is marked with an artificial marker that can be distinguishably recognized by the image recognition subsystem.Using the property of differential flatness, a dynamic feedback compensator can be designed for the system, thereby extending the system into a linear form. The presented control algorithm for reference tracking combines a feedforward and a feedback loop, the structure also known as a two DOF control scheme. The feedforward part should drive the system to the vicinity of the reference trajectory and the feedback part should eliminate any errors that occur due to noise and other disturbances etc. The feedforward control can never achieve accurate reference following, but this deficiency can be eliminated with the introduction of the feedback loop. The design of the model predictive control is based on the linear error model. The model predictive control is given in analytical form, so the computational burden is kept at a reasonable level for real-time implementation. The control algorithm requires that a reference trajectory is at least twice differentiable function. A suitable approach to design such a trajectory is by exploiting some useful properties of the Bernstein-Bézier parametric curves. The simulation experiments as well as real system experiments on a robot normally used in the robot soccer small league prove the applicability of the presented control approach.