  We present a concept of constrained collaborative mobile agents (CCMA)
system, which consists of multiple wheeled mobile agents constrained by a
passive kinematic chain. This mobile robotic system is modular in nature, the
passive kinematic chain can be easily replaced with different designs and
morphologies for different functions and task adaptability. Depending solely on
the actuation of the mobile agents, this mobile robotic system can manipulate
or position an end-effector. However, the complexity of the system due to
presence of several mobile agents, passivity of the kinematic chain and the
nature of the constrained collaborative manipulation requires development of an
optimization framework. We therefore present an optimization framework for
forward simulation and kinematic control of this system. With this optimization
framework, the number of deployed mobile agents, actuation schemes, the design
and morphology of the passive kinematic chain can be easily changed, which
reinforces the modularity and collaborative aspects of the mobile robotic
system. We present results, in simulation, for spatial 4-DOF to 6-DOF CCMA
system examples. Finally, we present experimental quantitative results for two
different fabricated 4-DOF prototypes, which demonstrate different actuation
schemes, control and collaborative manipulation of an end-effector.
