Velin D. Dimitrov

Hierarchical Navigation Architecture and Robotic Arm Controller for a Sample Return Rover

This work presents a hierarchical navigation architecture and cascade classifier for sample search and identification on a space exploration rover. A three tier navigation architecture and inverse Jacobian based robot arm controller are presented. The algorithms are implemented on AERO, the Autonomous Exploration Rover, participating in the NASA Sample Return Robot Centennial Challenge in 2013 and initial results are demonstrated.

Towards supervisory control of humanoid robots for driving vehicles during disaster response missions

We describe the approach of Worcester Polytechnic Institutes (WPI) Robotics Engineering C Squad (WRECS)to the utility vehicle driving task at the Defense Advanced Research Projects Agency (DARPA) Robotics Challenge (DRC) Trials held in December 2013. WRECS was one of only seven teams to attempt the driving task, and the only team with an ATLAS robot to successfully drive the course. We implement a supervisory control system that allows the robot to control the speed of the vehicle, while the operator helps the robot steer the vehicle. Two different methods of estimating speed, using the LIDAR and stereo cameras, are presented, and the performance of the robot at the Trials is discussed.

A shared control architecture for human-in-the-loop robotics applications

We propose a shared control architecture to enable the modeling of human-in-the-loop cyber physical systems (HiLCPS) in robotics applications. We identify challenges that currently hinder ideas and concepts from cross-domain applications to be shared among different implementation of HiLCPS. The presented architecture is developed with the intent to help bridge the gap between different communities developing HiLCPS by providing a common framework, associated metrics, and associated language to describe individual elements. We provide examples from two different domains, disaster robotics and assistive robotics, to demonstrate the structure of the architecture.

A comparative study of teleoperated and autonomous task completion for sample return rover missions

This research is aimed at identifying a minimal set of shared control behaviors that would optimize the execution of high-level tasks in terms of robot capabilities and operator engagement in sample return missions. Previous robotic missions to the Moon and Mars, such as Mars Science Laboratory, have relied on supervised autonomy and teleoperation with latency mission scenarios. While this has proven to be an effective approach especially with regard to minimizing mission risks, its scalability to multi-rover systems controlled by a single-operator poses challenges as meticulous planning on daily mission objectives is required and mission success relies heavily on robust, low-latency communication channels. As missions evolve to include multiple robotic platforms exploring celestial bodies farther than Mars, a paradigm shift in mission design approach is required. While completely autonomous exploration rovers may someday be commonly utilized, we aim to show that selectively adding high-level shared control behaviors to execute a sample return mission can significantly improve efficiency at an acceptable addition of risk and complexity.

Kinematic Control of a Planetary Exploration Rover over Rough Terrain

Passive averaging suspensions have been proven highly effective on rovers for improving mobility by providing ground compliance. However, the passive degree of freedom poses an added challenge to the controls problem. This paper presents a controller design to increase the accuracy of straight line trajectories for rovers with passive suspension on rough terrain. The chosen approach uses only proprioceptive sensors, a 3D kinematic model, and a trivial ground plane estimator algorithm to adjust individual wheel velocities based on estimates of terrain slope. This has distinct advantages to other techniques that use global position sensors and dynamic models which inevitably lead to more complex and computationally intensive solutions. The proposed controller is simulated in Matlab and found to be successful through experiments conducted with ORYX 2.0, a planetary rover research platform. This paper presents the feed forward velocity controller design, simulations, and experimental results for validation.

Towards user-centered design of a robotic prosthetic hand with EMG control interfaces

We present the design evolution of robotic prosthetic hands at WPI over the last couple years. Following a user-centered design approach, we have identified a series of requirements that good prosthetic hand designs should have. We describe in detail the mechanical, electrical, and software subsystems of each hand, and the relative advantages and disadvantages of the design decisions made during the development phases. In addition, we describe, in depth, our work towards an intuitive and high bandwidth EMG interface for assistive products. We compare various amplifiers and their performance for our implementation of an EMG interface.

User-centric design of a personal assistance robot (FRASIER) for active aging

We present our preliminary results from the design process for developing the Worcester Polytechnic Institutes personal assistance robot, FRASIER, as an intelligent service robot for enabling active aging. The robot capabilities include vision-based object detection, tracking the user and help with carrying heavy items such as grocery bags or cafeteria trays. This work-in-progress report outlines our motivation and approach to developing the next generation of service robots for the elderly. Our main contribution in this paper is the development of a set of specifications based on the adopted user-centered design process, and realization of the prototype system designed to meet these specifications.

A cyber physical system testbed for assistive robotics technologies in the home

We present a cyber-physical system (CPS) testbed to enable the rapid development, testing, and deployment of assistive robotics technologies in the home of elderly individuals. We built a CPS testbed in a lab environment with initial capabilities allowing for the testing of both individual systems and collections of systems. The CPS testbed has communication, computation, sensing, and control resources available that can be leveraged by individual subsystems within the CPS. We present projects built by different design teams to be integrated in the CPS environment to help the elderly live independent lives and age in place. Finally, we describe a case study for the use of a mobile robot within the CPS to detect and respond in case an elderly person falls at home.

Human-centered design of a cyber-physical system for advanced response to Ebola (CARE).

We describe the process towards the design of a safe, reliable, and intuitive emergency treatment unit to facilitate a higher degree of safety and situational awareness for medical staff, leading to an increased level of patient care during an epidemic outbreak in an unprepared, underdeveloped, or disaster stricken area. We start with a human-centered design process to understand the design challenge of working with Ebola treatment units in Western Africa in the latest Ebola outbreak, and show preliminary work towards cyber-physical technologies applicable to potentially helping during the next outbreak.

Realization of vision-based navigation and object recognition algorithms for the sample return challenge

We present the improvements to AERO, the Autonomous Exploration Rover, developed for the 2014 NASA Sample Return Robot competition with the intent of enabling more robust and reliable autonomous operation for sample return rovers. The competition requires the robot to navigate a large outdoor area, find and collect various geologic samples, and return to the starting platform all autonomously and utilizing only space compatible technologies. We highlight improvements made in the implementation and deployment of the vision, navigation, and planning systems. We describe the process of modifying the software to be closer aligned with ROS standard practices, resulting in more predictable and stable operation. We conclude by providing a roadmap for the integration of multiple heterogeneous systems in a shared control framework to enable efficient exploration of large unknown environments.