Kinetic Analysis of Active Omni Wheel With Barrel-Shaped Rollers for Avoiding Slippage and Vibration

Paper No: JMR-23-1080Omnidirectional mobility is required for the efficient movement of transport vehicles in factories and warehouses. To meet this requirement, the active omni wheel with barrel-shaped rollers (AOWBR) was previously proposed. The barrel-shaped rollers are arranged around the outer circumference of the main wheel of the AOWBR. This structure is expected to be effective in suppressing vibration during vehicle movement. The transmission roller drives the outer roller via a friction drive, which actively moves the AOWBR in the lateral direction. However, the friction drive may cause slippage between the transmission roller and the outer roller. To solve this problem, this study investigates the effects of the design parameters for an AOWBR on vibration and wheel slippage. The kinetic models of the wheel main body, transmission roller, and outer roller are established. Then, simulations are carried out using the kinetic models for various structural parameter values. The simulation results show that a softer rubber block installed in the support mechanism of the outer roller contributes to reduce wheel slippage but cause larger vibration, and that a larger setting angle between the transmission and outer rollers contributes to reduce slippage and vibration. Finally, comparison experiments are conducted on two types of prototype to verify the simulation results

Motion Characteristics Analysis of a Mecanum-Wheeled Omnidirectional Mobile Robot on a Slope

Mechanisms and Machine Science book series (Mechan. Machine Science, volume 148)the 16th IFToMM World Congress 2023Mecanum-wheeled omnidirectional mobile robots (MOMRs) are widely used in the field of industry. However, since the mobility of the Mecanum wheel depends on the free rollers, limitations or undesirable behaviors may occur in the motions of the MOMR, especially when external forces are applied. Therefore, this study investigates the motion characteristics of the MOMR on a slope. First, we focus on the maximum possible acceleration considering the wheel skidding and clarify its relationship with the inclination angle of the slope and the structure of the MOMR. Then, the straight-traveling stability at the acceleration limit is analyzed to evaluate the effect of the resultant motion due to wheel skidding. The results show that the characteristics vary considerably depending on the inclination angle of the slope, and that directional dependences due to the free rollers are observed in the maximum acceleration limit and the straight-traveling stability, which should be considered in the operation of MOMRs