Spline Based Trajectory Planning for Cooperative Crane Lifts

2009 IEEE/RSJ …, 2009

Abstract—In this paper we consider the motion planning problem for a kinematically redundant manipulator which is used on forestry machines for logging. The analysis of recorded data from human operation forms the basis of our investigation. Replanning the ...

The efficiency of overhead traveling crane transportation is limited by payload swing induced by velocity change of the crane. To obtain high efficiency, this study introduced an ideal trajectory for crane's speed trajectory tracking controller. Pontryagin's maximum principle was used to develop an optimal trajectory to minimize the swing angle of payload based on the kinematic model of overhead traveling crane with constant hoist rope length. A simplified trajectory which is more convenience for engineering practice is introduced and some properties of the optimal trajectory are discussed by using the simplified version. Theoretical analysis has shown that the proposed optimal trajectory and its simplified version can reach a given velocity in a given time with a minimum payload swing. Methods introduced can be applied to motion planning for overhead traveling crane.

Key Engineering Materials, 2013

Design of state-of-the art crane mechanisms involves a multi-stage and multi-criterial optimization. Depending on the specificity and intended use of the machine, the optimal structure and dimensions of its mechanisms are sought as well as optimal algorithms for drive control and regulation, which requires the application of optimization criteria. It appears, however, that the approach relying on the minimum of a specifically formulated quadratic functional enables the selection of optimal geometric parameters of the mechanism and, besides, proves effective as the method of drive control. Furthermore, the geometric parameters of the mechanism can be optimized for its entire working range. Simplicity, universality and efficiency of the method are demonstrated on the example of a slewing one-link jib crane system. The search for the optimal control strategy of drive mechanisms is illustrated in the study that investigates an asymmetrically loaded platform suspended on ropes and people...

Automation in Construction, 2018

When a truck crane lifts a load, the most important considerations are the safety and efficiency of the lift path; therefore, the objectives in planning a lift path should be the minimization of both the path length and number of operations. Most proposed methods for lift-path planning simply focused on the optimization of the path length. As a result, a planned path may include a large number of operations that makes the path complicated and degrades the safety and efficiency of the lift process. This paper presents a method to optimize the number of operations for a lift path with an optimized length for a truck crane by making the most efficient use of the crane characteristics. First, a conventional search algorithm is used to optimize the length of a lift path. Thereafter, a new operating-path optimization method is presented to reduce the number of points on the planned path based on construction of simple spaces and fundamental operating paths. Simulations produced satisfactory results, demonstrating that this method reduces the number of operations on a short lift path, thereby improving the safety and efficiency.

2008

The incremental coordination method a computational method for preplanning and coordinating the use of multiple tower cranes in relatively narrow construction sites is presented. The incremental coordination method considers the kinematics and the geometrical constraints of cranes to plan the motion of two or more cranes, which are being operated in collaboration. By following such planned motions, erection tasks are completed safely, even when the cranes are operated in close proximity of each other. This method allows the use of computers to plan and coordinate the crane activities from start to end of an erection process. This paper also explains the computational methods required by the incremental coordinate method including path-finding and collision detecting methods. An example case shows two construction cranes, each of three degrees-of-freedom, operating together on a building project where the working areas of the cranes intersect, hence possibility colliding with each other. A numerical test was conducted to verify the efficiency and effectiveness of applying the incremental coordination method in planning and synchronizing all motions of the two cranes to avoid any collision between the cranes themselves and collision with obstacles on the construction site.

Journal of Mechanical Science and Technology, 2014

This paper proposes a novel off-line trolley trajectory planning method for underactuated overhead cranes. The proposed technique is feasible and efficient for overhead crane operation. Dynamic coupling between trolley motion and payload swing was successfully exploited using a staircase form of trolley acceleration. The payload swings in the constant velocity phase were efficiently suppressed and the trolley reached the desired position using this technique. The reasonable number of stairs can be determined by evaluating the residual oscillation amplitude according to the number of stairs and variation in the natural frequency of the pendulum. The proposed approach was first simulated from the kinematics viewpoint to verify the validity of the trolley trajectory and the swing angle of the payload. The proposed approach was then combined with the dynamics of the overall crane, wherein the robust sliding mode controller was applied to ensure that the trolley tracks the designed trajectory. The numerical simulation results demonstrated superior performance and robustness against parameter uncertainties of the proposed method. The proposed method exhibited potential for application in the control of underactuated systems, such as overhead cranes, single-link flexible-joint manipulators, and flexible Cartesian manipulators.

Automation in Construction, 2020

Computer-Aided Lift Planning (CALP) systems provide smart and optimal solutions for automatic crane lifting, supported by intelligent decision-making and planning algorithms along with computer graphics and simulations. Re-planning collision-free optimal lifting paths in near real-time is an essential feature for a robotized crane operating in a construction environment that is changing with time. The primary focus of the present research work is to develop a re-planning module for the CALP system designed at Nanyang Technological University. The CALP system employs GPU-based parallelization approach for discrete and continuous collision detection as well as for path planning. Building Information Modeling (BIM) is utilized in the system, and a Single-level Depth Map (SDM) representation is implemented to reduce the huge data set of BIM models for usage in discrete and continuous collision detection. The proposed re-planning module constitutes of a Decision Support System (DSS) and a Path Re-planner (PRP). A novel re-planning decision making algorithm using multilevel Oriented Bounding Boxes (OBBs) is formulated for the DSS. A path re-planning strategy via updating the start configuration for the local path is devised for the PRP. Two case studies are carried out with real-world models of a building and a specific tower crane to validate the effective performance of the re-planning module. The results show excellent decision accuracy and near real-time re-planning with high optimality.

Journal of Sound and Vibration, 2015

A strategy for generating optimal shaped command-profile for the reduction of residual vibrations in rest-to-rest crane maneuvers is proposed. The technique used is based on generating discrete-time shaped acceleration profile. This profile accommodates simultaneous travel and hoist maneuvers in the presence of damping. The discrete-time acceleration profile is derived analytically using finite step segments. These segments are integrated into an input matrix coupled with a response matrix through a time varying equation of motion of the system. The input acceleration matrix is then optimized to satisfy specific rest-to-rest maneuver conditions. Several parameters are incorporated in the proposed strategy including maneuver time, time step, hoisting speed, damping, and maximum travel velocity and acceleration. Unlike traditional command shapers, the proposed strategy matches the discrete command signal steps to the machine minimum time step of the control hardware used. To achieve an optimum maneuvering time, the shaped command utilizes the full system acceleration and velocity capabilities. The resulting shaped command profile is capable of eliminating travel and residual oscillations. Successful performance of the proposed command shaping strategy is validated through numerical simulations and experiments on a scaled model of an overhead crane.

Mechanism and Machine Theory, 2019

A new composite polynomial is generated, to be used in the trajectory planning of a 2dof parallel mechanism; by combining cubic polynomials with Bézier curves based on quadratic Bernstein polynomials. By the cubic polynomials, a smooth trajectory is obtained in the vicinity of the starting and ending points, while a better convergence is obtained to the via points by the Bézier curves. The position, velocity, and acceleration profiles obtained using this new polynomial are compared with those obtained using the cubic polynomial spline method. The position, velocity, and acceleration profiles achieved by the new polynomial are smoother; and more, maximum speed and acceleration values are lower than those obtained by the cubic spline method. Due to these lower values, lower capacity actuators may be utilized and the life of the actuators may be extended. On the other hand, the continuous acceleration curve of the composite polynomial will prove less jerky motion, which means less vibration. It is also possible to indicate energy saving potential when considering the speed-torque characteristic curves of servomotors. Finally, a working prototype is manufactured and real-time experiments are carried out to demonstrate the validity and competency of the proposed composite polynomial approach.

2010

This paper presents a new path planning approach using Coevolutionary genetic algorithm (CGA) for automating the path planning of two Cooperative construction manipulators. A methodology based on the concept of configuration space (C-space) technique in conjunction with the Coevolutionary genetic search is used for generating the path. The paper proposes a method for finding the minimum distance and collision free path using CGA. It uses an interference detection algorithm that runs in parallel with CGA to check collision between obstacle and cooperative cranes during path planning. The effectiveness of CGA is compared with other search approaches like A* and Genetic Algorithms GA.