Past Projects

Sensory Feedback for Neuroprosthetic Devices

This research project seeks to develop and validate novel forms of sensory feedback, in particular haptic feedback, that enhance the interface between living and engineered systems for neuro-prosthetic applications. We propose to provoke an association in the brain that relates information detected using electromechanical sensors imbedded in the prosthesis to information presented to the body. The objective is to achieve a highly dexterous human-machine interface. We have developed a custom-built prosthetic device for upper-arm amputees and whole-bodied individuals. The device is controlled through electromyography (EMG) or position control, and provides enhanced sensory feedback.  (by:Jeremy Brown)

Eddy Current Motor Design and Performance Analysis

The eddy current motor project is aimed at developing a new class of motor that would better serve certain application needs in robotics (in particular haptic devices, or robots that interact with human users) than existing electromagnetic motors. The use of eddy currents has the potential to generate high torques on a rotor even when that rotor has an exceptionally small inertia. DC motors can’t do that. Low inertia is of particular interest in robots that interact with humans so that they are both safe and capable of simulating “free space”. Free space (what you feel when you wave your hands in thin air) has essentially zero inertia. Haptic devices equipped with traditional DC motors always have non-inconsiderable inertia, which is lacking in simulation free space. Haptic device is motorized (robotic) device meant to be grasped by a human user to allow them to manipulate virtual objects. High-fidelity feel of free space is always difficult to produce because of the significant inertia associated with traditional motors.  (by: Xinyi Ge)


Piano Gauge

Friction and balance weights are important properties of a piano key for piano manufacturers. Piano technicians try to obtain constant friction and balance weights to ensure a consistent feeling from key to key. To do this, they can spend up to 15 hours to measure and adjust the entire 88 keys for a piano. This an inconsistent, time-consuming process with poor repeatability, because several steps in the testing procedure are subjective and might vary between the technicians whom perform them. For example, technicians subjectively observe a ”smooth” motion. Moreover, tapping the piano frame also brings random factors.

We designed and built a linear flat voice coil motor with no bearings which has a programmable force output. The feature of applying no bearings ensures that no extra friction is involved in the piano keys’ measurement, and thus provides high accuracy. The entire apparatus is composed of three main parts: the linear motor, the base, and the control system. The base can be replaced with any other static mechanisms to fit the demand of use in different situations.  (by: Baoyan (Colin) Jian)


Haptic Interface Design for Piano Action

The objective of this project is to realize the real-time haptic rendering of piano action through a motorized synthesizer keyboard. We propose to construct a piano action model by adopting an empirical technique, specifically, a frequency-domain system-identification method. We fit a family of linear parametric models based on contact conditions of piano parts. We then assemble them computationally into a hybrid dynamical model. Motorized electronic keyboards will be designed to realize the real-time simulations of the hybrid dynamical model.  (by: Bo Yu)


Investigating Fundamental Limitations for Cooperative Multi-Agent Systems

Agents interconnected through virtual links are capable of displaying a larger and more interesting set of behaviors than agents interconnected through physical links. String instability is one example of a behavior that emerges from a multi-agent system (e.g. a platoon of autonomous vehicles) with virtual links. Only very recently have such statements been proved for agents using arbitrary control policies through analysis from the theory of fundamental design limitations. Significant gaps remain in the determination of fundamental design limits for cyber-physical systems. The goal of this project is to develop and extend design limitations theory to cover systems with oscillatory dynamics whose architectures feature both virtual and physical links and both computer and human control. In particular, we are interested in how the oscillator dynamics, communication topology, and human-controlled agents affect the string stability of the whole system. We believe such an analysis of fundamental limitations can illuminate the causes and possible remedies for string instability.  (by: Bo Yu)


Haptic Rendering of Hybrid Dynamical Systems

Extremal Distance Tracking
Parameter Estimation for Hybrid Dynamical Systems
On-line Symbolic Constraint Embedding
Fundamental Limitations of Tele-operation Performance

Haptic Interface for Vehicle Control

Shared Control of Vehicle Steering
Automotive Steer-by-wire Systems
Vibration Feed-through Cancellation

Human Motor Adaptation and Rehabilitation

Adaptation to Task Parameters in Object Manipulation
Power and Information Transfer with Haptic Feedback
Self-Assistance for Spinal Cord Injury Rehabilitation and Training
Upper-Extremity Stroke Rehabilitation
Upper Limb Tele-Rehabilitation
Sequence Learning