Mohammad Rokonuzzaman, Navid Mohajer, and Saeid Nahavandi. 7/7/2022. “
Effective adoption of vehicle models for autonomous vehicle path tracking: a switched MPC approach.” International Journal of Vehicle Mechanics and Mobility, 61, 5.
Publisher's VersionAbstractEfficient path tracking plays a key role in the overall ride experience of Autonomous Vehicles (AVs). Model Predictive Control (MPC) is one of the most competent techniques which is capable of handling multiple variables and constraints. The performance of this controller heavily relies on the proper choice of the vehicle model used to predict future states. This work proposes a novel MPC framework for the effective adoption of vehicle models to achieve a compromise between MPC’s performance and computational cost. To this aim, a Switched MPC (SMPC) using vehicle models with different levels of complexity and fidelity is developed. The SMPC uses a novel supervision scheme to adopt the appropriate vehicle model based on the models’ prediction error and MPC’s solution time. Two different configurations of SMPC are implemented: (1) A Fuzzy Logic System (FLS), and (2) An adaptive switching supervisor …
Mohsen Dalvand, Saeid Nahavandi, and Robert D. Howe. 6/6/2022. “
General Forward Kinematics for Tendon-Driven Continuum Robots,” 10, Pp. 60330 - 60340.
Publisher's VersionAbstractUnlike the inverse kinematics problem of n -tendon continuum robots, the forward kinematics problem lacks a closed-form analytical solution. In this paper, a novel forward kinematics algorithm for n -tendon single-segment flexible continuum robots is developed that can determine the resulting beam configuration for any given set of actuator displacements. The algorithm determines key parameters of all possible n - to 1-tendon combinations and examines them against evaluation criteria to find the final beam configuration as well as the active/slack status of the tendons at this configuration. The algorithm employs a previously developed analytical loading model for n -tendon continuum robots with general tendon positioning to evaluate the tension loads in tendons for each combination. Potential energy of the beam is also calculated for all combinations and utilized to choose among multiple potential solutions. The model is derived to account for the bending and axial compliance of the manipulator as well as tendon compliance. A multi-tendon continuum robot system is employed to experimentally evaluate the proposed forward kinematics solution. Multiple experiments are carried out for the exhaustive list of all possible combinations of different sets of tendon displacements and the results are reported. The proposed forward kinematics algorithm may be used to understand the implication of control errors and their nonlinear effects for optimal selection of hardware and control algorithm for safety and reliability purposes.
Ruth Cooper and Saeid Nahavandi. 6/2022. “
Feeling the full force of haptic technology https://createdigital.org.au/feeling-the-full-force-of-haptic-technology/”.
Publisher's VersionAbstract
Through his pioneering work integrating haptic technology into robots and virtual reality systems, Engineers Australia’s Professional Engineer of the Year Saeid Nahavandi is transforming how we engage with simulated experiences.....