Points-Based Safe Path Planning of Continuum Robots

Abstract

Continuum robots exhibit great potential in a number of challenging applications where traditional rigid link robots pose certain limitations, e.g.,working in unstructured environments. In order to enable the usage of continuum robots in safety-critical applications, such as surgery and nuclear decontamination, it is extremely important to ensure a safe path for the robot's movement. Existing algorithms for continuum robot path planning have certain limitations that need to be addressed. These include the fact that none of the algorithms provide safety assurance parameters and control for path planning. They are computationally expensive, applicable to a specific type of continuum robots, and mostly they do not incorporate design and kinematics constraints. In this paper, we propose a points-based path planning (PoPP) algorithm for continuum robots that computes the path by imposing safety constraints and improves upon the limitations of existing approaches. In the algorithm, we exploit the constant curvature-bending property of continuum robots in their path planning process. The algorithm is computationally efficient and provides a good tradeoff between accuracy and efficiency that can be implemented to enable the safety-critical application of continuum robots. This algorithm also provides information regarding path volume and flexibility in movement. Simulation results confirm that the algorithm possesses promising potential for all types of continuum robots (following the constant curvature-bending property). We believe that this effectively balances the desired safety and efficiency requirements.

Obstacle Avoidance for Redundant Manipulators Utilizing a Backward Quadratic Search Algorithm

“…In prior literature [2,13,[15][16][17], kinematically redundant manipulators' obstacle avoidance is dependent on the realtime determination of the obstacle avoidance point, contributing the greater portion of the method's computational load. Without the assistance of extra sensors, like laser range finders, cameras, etc., the search for the obstacle avoidance point that is least far from the obstacles on the links in the structured environment is conducted based on the computation of the Euclidean distance between every point on the obstacles' surface and manipulator links, for every iteration step.…”

“…Y. N. Zhang and J. Wang [14] improved the equality-based QP formulation in [13] to create an inequality-based one, and used a dual neural network to generate joint velocities. Recent progress in the kinematical method of obstacle avoidance can be found in [15][16][17]. Nevertheless, these methods require the identification of the obstacle avoidance point for every calculation step, which is time-consuming and sometimes difficult when the obstacle contour becomes complex.…”

A Review on Challenges of Autonomous Mobile Robot and Sensor Fusion Methods

“…Some of the main algorithms that can be used for obstacle avoidance are discussed in this section. Bug algorithm [50] is one of the earliest algorithms. It enables the robot to navigate the entire circumferences of the obstacle encountered and decide on the most appropriate point to leave towards the goal.…”

“…It enables the robot to rotate freely at angle less than 90 degrees to avoid obstacle. If the rotation is 90 degrees or greater and it is required to avoid an obstacle, it acts as bug-2 algorithm [50] and starting moving to destination when path is clear from obstacles. Conclusively, collision free algorithm is a requirement for autonomous mobile robot, since it provides safe trajectory.…”

Demonstration-Guided Pose Planning and Tracking for Multi-Section Continuum Robots Considering Robot Dynamics

“…In literature, several attempts have been made towards planning safe paths for continuum robots without taking into account their intrinsic compliance [5]. For instance, in [6], a points-based path planning (PoPP) algorithm was introduced to plan two-dimensional motions for constant-curvature continuum robots. To improve the limitations in the existing path planning techniques, the developed PoPP technique computes the path by considering two safety parameters; namely, the step size and the minimum marginal distance.…”