ABSTRACT

Motion planning of mobile manipulators is concerned with obtaining open

loop controls that steer the system from an initial configuration to a final

one, without violating nonholonomic constraints or collision avoidance con-

straints. Moving mobile manipulator systems presents many unique problems

that are due to the coupling of holonomic manipulators with nonholonomic

platforms. The path planning for a mobile manipulator accomplishing a se-

quence of coordination and manipulation tasks is formulated in [121] as a

nonlinear optimization problem with state boundary equality constraints and

a general cost function, which was solved using a stochastic algorithm of a

simulated annealing. Motion planning of mobile manipulators to execute mul-

of Mobile

tiple tasks consisting of a sequence of pre-specified trajectory in a fixed world

frame [122] is formulated as a global optimization problem and simultaneously

obtains the motion trajectory set and commutation configurations. A general

approach based on the calculus of variations was proposed for motion planning

for nonholonomic cooperating mobile robots to obtain optimal trajectories and

optimal actuator forces/torques in the presence of obstacles [123] such that

geometric constraints, kinematic constraints, and dynamic constraints can be

easily incorporated into the planning scheme. Navigating a mobile manipula-

tor among obstacles had been studied in [124] by simultaneously considering

the obstacle avoidance and the coordination. The developed control allows the

system to retain optimal or sub-optimal configurations while the manipulator

avoids obstacles using potential functions. In approach, it was assumed that

only the manipulator may encounter the obstacle, while in the same study

[125], the obstacle avoidance by the entire mobile manipulator system was

considered and the proposed nonholonomic motion planner is based on a dis-

continuous feedback law under the influence of a potential field. Motion plan-

ning applicable to handling deformable material by multiple nonholonomic

mobile manipulators was described in the obstacles environment [126], which

is based on a new class of nonsmooth Lyapunov functions and an extension

of the navigation function. The dipolar inverse Lyapunov functions and po-

tential field technique using diffeomorphic transformations were introduced

for nonholonomic control. The standard definition of manipulability was gen-

eralized to the case of mobile manipulators in [63], and the optimization of

criteria inherited from manipulability considerations was given to generate the

controls of the system when its end effector motion was imposed. Path plan-

ning of nonholonomic mobile platforms with manipulators in the presence

of obstacles was developed in [127], which employs smooth and continuous

functions such as polynomials and is based on mapping the nonholonomic

constraint to a space where it can be satisfied trivially. Motion planning for a

mobile manipulator with end-effector along a given path was developed by the

randomized generation of configurations that are compatible with the end ef-

fector path constraint [128]. A modular fuzzy navigation method and a robust

control in unstructured environments were developed for the navigation and

control of mobile manipulators by using fuzzy reactive motion planning and

robust adaptive control [129]. The probabilistic road map and the fuzzy reac-

tive planner based on elastic band for the vehicle platform to avoid unknown

static/dynamic obstacles are also presented [129].