This paper develops a computational technique for finding the maximum allowable ‎load of Mobile manipulators for a given trajectory. The maximum allowable loads ‎which can be achieved by a Mobile manipulator during a given trajectory are limited ‎by the number of factors; probably the dynamic properties of Mobile base and ‎mounted manipulator, their actuator limitations and additional constraints applied to ‎resolving the redundancy are the most important factors. To resolve extra D.O.F ‎introduced by the base mobility, additional constraint functions are proposed directly ‎in the task space of Mobile manipulator. Finally, in two numerical examples involving ‎a two-link planar manipulator mounted on a differentially driven Mobile base, ‎application of the method to determining maximum allowable load is verified. The ‎simulation results demonstrates the maximum allowable load on a desired trajectory ‎has not a unique value and directly depends on the additional constraint functions ‎which applies to resolve the motion redundancy‏.‏

Mobile platforms with one or more manipulators are of great interest for their wide area of applications and dexterity. Including a suspension system in such Mobile platforms will certainly add to their maneuverability, though causes more complexity. In this paper, a suspended Mobile platform with two 6-DOF manipulators is used to manipulate an object in a mixed circular-straight path. The Multiple Impedance control (MIC) as a Model-Based algorithm, enforces the same impedance law both on the robotic system, and the manipulated object level. To apply model-based control laws, however, it is needed to extract system dynamics equations. For such highly nonlinear dynamical systems, it is necessary to have a concise set of dynamic equations with as few as possible mathematical calculations. Therefore, the concept of Direct Path Method, is extended to derive explicit dynamics modeling for such challenging systems. Then non-holonomic constraint of the wheeled platform is discussed, and obtained dynamics model is reformatted to become more concise using Natural Orthogonal Complement Method. Next, the MIC law is applied to cooperative manipulation of an object by the two manipulators. The obtained results reveal the success of the suspended Mobile robot in its defined mission.

In this paper, design and manufacturing of a Mobile mechanical manipulator with flexible joints are presented. Ergonomic principals such as balancing the human height and anthropometric, enough space for moving, accessibility of the controllers, making environment labor-friendly adapting the manipulator with the load and anthropometric are considered in order to reduce harm and fatigue. First, the kinematics and dynamic equations of the mechanism with flexible joints for the three major axis of the Mobile robot are derived and simulated. Next, a method for determination of the dynamic load carrying capacity (DLCC) for a specific reference is explained subject to both accuracy and actuator constraints. The manipulator is tested for a given trajectory in order to find the characteristics of the designed manipulator. While the manipulator is designed to carry the maximum load, end-effector’s speed, robot's compatibility with the operator's condition, and accuracy are the most important applicable points of the manipulator. Therefore, the manipulator in different trajectories with various speeds and loads are tested, and then the results are analyzed.

In this paper, a nonlinear optimal feedback control law is designed to find the maximum load carrying capacity of Mobile manipulators for a given trajectory task. The optimal state feedback law is given by the solution to the nonlinear Hamilton-Jacobi-Bellman (HJB) equation. An iterative procedure is used to find a sequence of approximate solutions of the HJB equation. This is done by solving a sequence of Generalized HJB (GHJB) differential equations. The Galerkin procedure is applied to find a numerical solution to the GHJB equation. Using this method, a nonlinear feedback is designed for the Mobile manipulator and, then, an algorithm is developed to find the maximum payload. In Mobile base manipulators, the maximum allowable load is limited by their joint actuator capacity constraints, nonholonomic constraints and redundancy that arise from base mobility and increased Dofs. To solve the extra Dofs of the system, an extended Jacobian matrix and additional kinematic constraints are used. The validity of the methodology is demonstrated via simulation for a two-link wheeled Mobile manipulator and linear tracked Puma arm and the results are discussed.

The main purpose of this paper is to derive the inverse dynamic equation of motion of n-rigid robotic manipulator that mounted on a Mobile platform, systematically. To avoid the Lagrange multipliers associated with the nonholonomic constraints the approach of Gibbs-Appell formulation in recursive form is adopted. For modeling the system completely and precisely the dynamic interactions between the manipulator and the Mobile platform as well as both nonholonomic constraints associated with the no-slipping and the no-skidding conditions are also included. In order to reduce the computational complexity, all the mathematical operations are done by only 3×3 and 3×1 matrices. Also, all dynamic characteristics of a link are expressed in the same link local coordinate system. Finally, a computational simulation for a manipulator with five revolute joints that mounted on a Mobile platform is presented to show the ability of this algorithm in generating the equation of motion of Mobile robotic manipulators with high degree of freedom.