Bruce Minaker

Analysis and development of self-reconfigurable open kinematic machinery systems

This paper presents the analysis and development of the model, dynamics and control of new self-reconfigurable machinery systems. These machinery systems combine as many properties of different open kinematic structures as possible and can be used for a variety of applications. The kinematic design parameters, i.e., their Denavit-Hartenberg (D-H) parameters, can be modified to satisfy any configuration required to meet a specific task. By varying the joint twist angle parameter (configuration parameter), the presented model is reconfigurable to any desired open kinematic structure, such as Fanuc, ABB and SCARA robotic systems. The joint angle and the offset distance of the D-H parameters are also modeled as variable parameters (reconfigurable joint). The resulting self-reconfigurable machinery system hence encompasses different kinematic structures and has a reconfigurable joint to accommodate any required application. Using the Newton-Euler (N-E) recursive approach, the dynamic parameters of a reconfigurable joint are calculated and presented. A nonlinear control law is developed for a general reconfigurable joint using Lyapunov second method achieving asymptotic stability and the required performance objectives. Automatic model generation of a 3-DOF reconfigurable machinery system is constructed and demonstrated as a case study which covers all possible open kinematic structures. This research is intended to serve as a foundation for future studies in reconfigurable control systems.

Design considerations for permanent magnet machine drives for direct-drive electric vehicles

Understanding the need for improvement in efficiency of an electric vehicle drivetrain system, this paper exclusively discusses various design aspects of a permanent magnet machine drive for direct-drive electric vehicles (EV). Firstly, the motivation to employ a direct-drive configuration in EV is discussed. Thereafter, initial electric machine rating design considerations for a typical Supermini or B-segment EV employing a direct-drive configuration is discussed. Furthermore, employing an existing stator, investigations are performed through analytical equations and designed machines to understand different permanent magnet machine design aspects with regards to selection of: number of poles, type of permanent magnet rotor, stator winding configuration and number of phases. The study performed here will assist in providing decision points on various structural design indices of the machine before venturing into the FEA based permanent magnet machine design and assessment for the direct-drive EV application.

Kinematic properties and control for reconfigurable robotic system

This paper presents the kinematic aspects of reconfigurable manipulators such as workspace, manipulability and singularity properties. These properties are calculated and shown in 3D figures. Variable control structures are designed for reconfigurable robotic systems. These robotic systems combine as many properties of different open kinematic structures as possible and can be used for a variety of applications. The kinematic design parameters, i.e., their Denavit-Hartenberg (D-H) parameters, can be modified to satisfy any configuration required to meet a specific task. By varying the joint twist angle parameter (configuration parameter), the presented model is reconfigurable to any desired open kinematic structure, such as ABB, Stanford and SCARA robotic systems. The joint angle and the offset distance of the D-H parameters are also modeled as variable parameters (reconfigurable joint). The resulting self-reconfigurable robotic system hence encompasses different kinematic structures and has a reconfigurable joint to accommodate any required application in medical technology, space exploration and future manufacturing systems among others. A 3-DOF reconfigurable robotic system is constructed and demonstrated as a case study which covers all possible open kinematic structures. SMC controllers were developed based on estimated, bounded models and on computed torque method. This research is intended to serve as a foundation for future studies in reconfigurable control systems.

On-board direct-drive surface permanent magnet synchronous machine with fractional-slot concentrated windings for electric vehicles

Removal of the gear-box from an existing electric vehicle (EV) power-train incorporating direct-drive topology is expected to improve motor-to-wheel efficiency. Firstly, this paper discusses the need for a novel direct-drive scheme employing a single on-board motor in an EV. Electric machine and drive design targets for such a supermini EV with direct-drive scheme are fixed based on analytical equations, benchmark data obtained from commercially available EV motors, drives, transmissions and literature study. Employing a comprehensive vehicle dynamics model of the supermini EV, machine design targets previously fixed are further refined to yield desired dynamic and steady-state performance of the EV over an urban drive cycle. An on-board direct-drive surface permanent magnet synchronous machine with fractional slot concentrated windings in the stator is designed. The machines performance is then analyzed using its electromagnetic model in conjunction with maximum-torque-per-ampere control scheme over the entire speed range of the motor. Results from finite element analysis are discussed in detail to show that that the proposed direct-drive scheme in EV is worth studying and the machine designed can be improved in order to obtain efficiency improvement in an EV drivetrain system and hence extend the driving range of EV.

An Adaptive Sliding Mode Control for Trajectory Tracking of a Self-reconfigurable Robotic System

This paper presents the development of the model, dynamics and an adaptive sliding mode control of new self-reconfigurable robotic systems. These robotic systems combine as many properties of different open kinematic structures as possible and can be used for a variety of applications. The kinematic design parameters, i.e., their Denavit-Hartenberg (D-H) parameters, can be modified to satisfy any configuration required to meet a specific task. By varying the joint twist angle parameter (configuration parameter), the presented model is reconfigurable to any desired open kinematic structure, such as Fanuc, ABB and SCARA robotic systems. The joint angle and the offset distance of the D-H parameters are also modeled as variable parameters (reconfigurable joint). The resulting self-reconfigurable robotic system hence encompasses different kinematic structures and has a reconfigurable joint to accommodate any required application in medical, space, future manufacturing systems, etc. Automatic model generation of a 3-DOF reconfigurable robotic system is constructed and demonstrated as a case study which covers all possible open kinematic structures. An adaptive controller is developed based on the sliding mode approach for a 3-DOF self-reconfigurable robotic system to achieve high tracking performance. This research is intended to serve as a foundation for future studies in reconfigurable control systems.