Jan Paul Huissoon

Image processing and classification algorithm for yeast cell morphology in a microfluidic chip

The study of yeast cell morphology requires consistent identification of cell cycle phases based on cell bud size. A computer-based image processing algorithm is designed to automatically classify microscopic images of yeast cells in a microfluidic channel environment. The images were enhanced to reduce background noise, and a robust segmentation algorithm is developed to extract geometrical features including compactness, axis ratio, and bud size. The features are then used for classification, and the accuracy of various machine-learning classifiers is compared. The linear support vector machine, distance-based classification, and k-nearest-neighbor algorithm were the classifiers used in this experiment. The performance of the system under various illumination and focusing conditions were also tested. The results suggest it is possible to automatically classify yeast cells based on their morphological characteristics with noisy and low-contrast images.

Markov-Based Lane Positioning Using Intervehicle Communication

The majority of todays navigation techniques for intelligent transportation systems use global positioning systems (GPS) that can provide position information with bounded errors. However, due to the low accuracy that is experienced with standard GPS, it is difficult to determine a vehicles position at lane level. Using a Markov-based approach based on sharing information among a group of vehicles that are traveling within communication range, the lane positions of vehicles can be found. The algorithms effectiveness is shown in both simulations and experiments with real data.

Three-dimensional numerical approach for geometrical prediction of multilayer laser solid freeform fabrication process

This article presents the development of a three-dimensional numerical method for predicting transient geometrical and thermal characteristics of multilayer laser solid freeform fabrication as a function of process parameters and material properties. In the proposed method, the thermal domain is numerically obtained, assuming the interaction between the laser beam and powder stream is to be decoupled. Once the melt pool boundary is obtained, the physical domain is discretized in a cross-sectional direction. Based on the powder feed rate, elapsed time, and intersection of the melt pool and powder stream area substrate, layers of additive material are then added onto the nonplanar domain. A standard object is fit to each added layer to facilitate the numerical analysis of successive layers. Variations in physical parameters due to formation of nonplanar surfaces are incorporated into the model to increase the accuracy and reliability of the simulated results. The developed model was used to predict the geometrical and thermal properties of a four-layer thin wall of AISI 4340 steel. The results show that the temperature and the thickness of the deposited layers sensibly increase at the end point of layers 2, 3, and 4. Also, the powder catchment efficiency for the first layer is significantly lower than those of successive layers. The experimental results demonstrate the validity of the developed numerical methodology.This article presents the development of a three-dimensional numerical method for predicting transient geometrical and thermal characteristics of multilayer laser solid freeform fabrication as a function of process parameters and material properties. In the proposed method, the thermal domain is numerically obtained, assuming the interaction between the laser beam and powder stream is to be decoupled. Once the melt pool boundary is obtained, the physical domain is discretized in a cross-sectional direction. Based on the powder feed rate, elapsed time, and intersection of the melt pool and powder stream area substrate, layers of additive material are then added onto the nonplanar domain. A standard object is fit to each added layer to facilitate the numerical analysis of successive layers. Variations in physical parameters due to formation of nonplanar surfaces are incorporated into the model to increase the accuracy and reliability of the simulated results. The developed model was used to predict the geom...

Localization in urban environments by matching ground level video images with an aerial image

This paper presents the design of a monocular vision based particle filter localization system for urban settings that uses aerial orthoimagery as the reference map. One of the design objectives is to provide a low cost method for outdoor localization using a single camera. This relaxes the need for global positioning system (GPS) which may experience degraded reliability in urban settings. The second objective is to study the achievable localization performance with the aforementioned resources. Image processing techniques are employed to create a feature map from an aerial image, and also to extract features from camera images to provide observations that are used by a particle filter for localization.

Uni-drive modular robots: theory, design, and experiments

A modular serial robot consists of a chain of links and joints such that its configuration can be changed by the order and number of links and joints. Although theoretically a modular robot can take any configuration, the weight of the modules is usually the limiting factor in the number of modules that can be chained together. Since the actuator often contributes a significant portion of the module weight, this is reduced in the proposed design by replacing the actuator with a pair of clutches. Drive torque for the module is tapped from a central rotating shaft using these clutches, the central shaft being continuously driven by a single base-mounted motor. The position and velocity of the modules are regulated by controlling the engagement time of the clutches using the pulse width modulation technique. An experimental 2-axis gantry robot based on the modular uni-drive concept has been designed and fabricated. The mathematical model of the gantry robot is developed and experimental and simulation results are compared.

Optimized Lane Assignment Using Inter-Vehicle Communication

This paper presents an approach to lane assignment for highway vehicles that increases traffic throughput while ensuring they exit successfully at their destinations. Most of current traffic management systems do not consider lane organization of vehicles and only regulate traffic flows by controlling traffic signals or ramp meters. However, traffic throughput and efficient use of highways can be increased by coordinating driver behaviors intelligently. The goal of this research is to form a distributed control strategy for cars themselves to select lanes using inter-vehicle communication. Initial results are promising and demonstrate that intelligent lane selection can decrease vehicle traffic time.

Distributed platoon assignment and lane selection for traffic flow optimization

This paper presents an approach to lane assignment for highway vehicles that increases traffic throughput while ensuring vehicles can exit successfully at their destinations. To enhance traffic safety and increase lane capacities, vehicles can be organized into platoons with the objective of maximizing the travel distance that platoons stay intact and then apply lane assignment to these platoons. The goal of this research is to form a distributed control strategy to select lanes for platoons using inter-vehicle communication. We evaluate the current platoon lane assignment strategy and compare its improvement over average vehicle travel time with the lane assignment for single vehicles reported in our previous work. Simulation results show that while cooperate control for single vehicle lane assignment does lead to decreased vehicle travel times, the implementation of cooperative lane assignment for platooning vehicles leads to an even greater reduction.

On the design of a direct drive 5-bar-linkage manipulator

The 5-bar-linkage manipulator configuration is well suited to many industrial robotic applications. Aside from kinematic suitability, the dynamic equations are greatly simplified due to a decoupling of the manipulator inertia matrix. The design also lends itself to the use of direct drive motors. However, these motors must be capable of providing a high continuous torque to counter gravitational loading in the conventional manipulator design. In this paper, the static and dynamic design of the 5-bar-linkage manipulator is analysed. A technique is proposed whereby the motor torque requirements may be reduced to a fraction of those required in the conventional design, while simultaneously retaining the advantage of a decoupled inertia matrix. Details of a prototype manipulator and experimental results of its performance are presented.

Development of a patient-specific anatomical foot model from structured light scan data

The use of anatomically accurate finite element (FE) models of the human foot in research studies has increased rapidly in recent years. Uses for FE foot models include advancing knowledge of orthotic design, shoe design, ankle–foot orthoses, pathomechanics, locomotion, plantar pressure, tissue mechanics, plantar fasciitis, joint stress and surgical interventions. Similar applications but for clinical use on a per-patient basis would also be on the rise if it were not for the high costs associated with developing patient-specific anatomical foot models. High costs arise primarily from the expense and challenges of acquiring anatomical data via magnetic resonance imaging (MRI) or computed tomography (CT) and reconstructing the three-dimensional models. The proposed solution morphs detailed anatomy from skin surface geometry and anatomical landmarks of a generic foot model (developed from CT or MRI) to surface geometry and anatomical landmarks acquired from an inexpensive structured light scan of a foot. The method yields a patient-specific anatomical foot model at a fraction of the cost of standard methods. Average error for bone surfaces was 2.53 mm for the six experiments completed. Highest accuracy occurred in the mid-foot and lowest in the forefoot due to the small, irregular bones of the toes. The method must be validated in the intended application to determine if the resulting errors are acceptable.

Robotic laser welding: seam sensor and laser focal frame registration

Robotic laser welding places extreme demands on the spatial accuracy with which the robot must position the focal point of the laser with respect to the joint to be welded. The required level of accuracy is difficult to achieve in a production environment without the use of end-point sensor based control of the robot. This requires that the end-point sensor frame and welding laser frame be accurately calibrated with respect to each other, as well as with respect to the robot wrist frame. This calibration can be difficult to perform since the sensor and laser frames are virtual in the sense that these are located in space with respect to the physical hardware, and the wrist frame of the robot is often not physically accessible. This paper presents the design of a calibration system with which these frames may be precisely defined with respect to each other.