The use of conventional actuators in robotic systems (electric motors in particular), while often offering advantages in terms of flexibility and controllability, suffer from primary actuator failure, due to unexpected complexities in their environment, which can lead to loss of controllability. Conventional actuators can impose disadvantages on mechanical complexity, weight, and cost. Here, the Mixed conventional/braking Actuation Mobile Robot (MAMR), a new mobile robot platform, is proposed to tackle such drawbacks in actuation and explore the use and control of braking actuation. This platform substitutes the drive motors used in Ackermann steering with brakes that have only two states, ON and OFF. Additionally, the conventional drive wheels are replaced by a single, omni-directional wheel that only supports a driving force in the robots longitudinal direction. The ability of braking actuators in providing controllability under actuator failure is one of the primary motivations of this work. To validate the reliability and accuracy of MAMR approach, this paper studies the design of such robotic systems, the design and synthesis of fuzzy logic controllers along with the experimental assessments of these controllers in real-time. The experimental tests point out the controller performance enhancement using fuzzy logic controllers and MAMR.

This paper presents the design of a novel mixed conventional/braking actuation mobile robot (MAMR), which replaces conventional actuators used for steering with controllable brakes. The mechatronic design of a novel electromechanical braking actuator, its implementation in the MAMR, and the mechatronic design of the MAMR are presented. A motion experiment is also given as a demonstration. The MAMR presented in this paper implements a new platform for mobile robots which is composed of two electromechanical braking actuators and an omni-directional drive wheel. The electromechanical brake presented is an omni-directional ball transfer that is electronically lockable. When the brake is in the locked state, it generates a reactive friction force onto a dynamic system that, in the case of the MAMR, can be used to steer and brake. This platform offers a minimalistic approach to locomotion in mobile robots.

No abstract

The Mixed convention/braking Actuation Mobile Robot (MAMR) was designed to tackle some of the drawbacks of conventional mobile robots such as losing controllability due to primary actuator failures, mechanical complexity, weight, and cost. It replaces conventional steering wheels with braking actuators and conventional drive wheels with a single omni-directional wheel. This makes it fall under the category of under-actuated mobile robots. The brakes have only two states, ON and OFF, resulting in discontinuous dynamics. This inspires the use of a discontinuous control law to control the system. This work presents a Sliding Mode Controller (SMC) design to park the MAMR system from a given initial configuration to a desired final configuration. Experimental results are presented to validate the parking control of the MAMR.