Jared Giesbrecht

A vision-based robotic follower vehicle

This paper presents the development of a vision-based robotic follower system with the eventual goal of autonomous convoying. The follower vehicle, trained at run-time, tracks an arbitrary lead vehicle and estimates the leaders position from the sequence of video images. Pan, tilt and zoom keep the leader in the followers field of view as it drives the leaders path. The system was demonstrated following vehicles in an on-road scenario, as well as dismounted human leaders off-road.

Software Systems for Robotics An Applied Research Perspective

Over the past 20 years, Defence Research and Development Canada has developed numerous tele-operated unmanned ground vehicles (UGV), many founded on the ANCÆUS command and control system. This paper relates how long experience with tele-operated UGVs influenced DRDCs shift in focus from tele-operated to autonomous unmanned vehicles (UV), the forces that guided DRDCs development approach and DRDCs experience adapting a specific tool set, MIRO, to a UGV implementation.

Architecture for autonomy

In 2002 Defence R&D Canada changed research direction from pure tele-operated land vehicles to general autonomy for land, air, and sea craft. The unique constraints of the military environment coupled with the complexity of autonomous systems drove DRDC to carefully plan a research and development infrastructure that would provide state of the art tools without restricting research scope. DRDCs long term objectives for its autonomy program address disparate unmanned ground vehicle (UGV), unattended ground sensor (UGS), air (UAV), and subsea and surface (UUV and USV) vehicles operating together with minimal human oversight. Individually, these systems will range in complexity from simple reconnaissance mini-UAVs streaming video to sophisticated autonomous combat UGVs exploiting embedded and remote sensing. Together, these systems can provide low risk, long endurance, battlefield services assuming they can communicate and cooperate with manned and unmanned systems. A key enabling technology for this new research is a software architecture capable of meeting both DRDCs current and future requirements. DRDC built upon recent advances in the computing science field while developing its software architecture know as the Architecture for Autonomy (AFA). Although a well established practice in computing science, frameworks have only recently entered common use by unmanned vehicles. For industry and government, the complexity, cost, and time to re-implement stable systems often exceeds the perceived benefits of adopting a modern software infrastructure. Thus, most persevere with legacy software, adapting and modifying software when and wherever possible or necessary -- adopting strategic software frameworks only when no justifiable legacy exists. Conversely, academic programs with short one or two year projects frequently exploit strategic software frameworks but with little enduring impact. The open-source movement radically changes this picture. Academic frameworks, open to public scrutiny and modification, now rival commercial frameworks in both quality and economic impact. Further, industry now realizes that open source frameworks can reduce cost and risk of systems engineering. This paper describes the Architecture for Autonomy implemented by DRDC and how this architecture meets DRDCs current needs. It also presents an argument for why this architecture should also satisfy DRDCs future requirements as well.

Integration of a high degree of freedom robotic manipulator on a large unmanned ground vehicle

The Multi-Agent Tactical Sentry Unmanned Ground Vehicle, developed at Defence R&D Canada - Suffield, has been in service with the Canadian Forces for five years. This tele-operated wheeled vehicle provides a capability for point detection of chemical, biological, radiological, and nuclear agents. Based on user experience, it is obvious that a manipulator capability would greatly enhance the vehicles utility and increase its mobility in urban terrain. This paper details technical components of this development, and describes a number of trials undertaken to perform tasks with a manipulator arm such as picking up objects, opening vehicle and building doors, recording video, and creating 3D models of the environment. The lessons learned from these trials will guide further development of the technology.

Vision-Based Vehicle Trajectory Following with Constant Time Delay

A convoy problem is formulated and solved for two four-wheeled vehicles. The task is for the second vehicle to follow the leader’s trajectory with a constant time delay. This delayed trajectory can be viewed as the trajectory of a delayed leader. This novel constant-time-delay concept allows for the estimation of the delayed leader’s speed and heading using the vehicle kinematics. Decoupled longitudinal and lateral controllers are developed based on the constant-time-delay approach. The lateral controller includes a look-ahead feature to compensate for steering delays. Successful field trials were conducted with full-sized military vehicles on a 1.3-kilometre test track. The tracking errors from differential global positioning system (DGPS) ground truth covering 13 kilometres are presented.

A Concept for Docking a UUV With a Slowly Moving Submarine Under Waves

Docking an unmanned underwater vehicle (UUV) with a submerged submarine in littoral waters in high sea states requires more dexterity than either the submarine or streamlined UUV possess. The proposed solution uses an automated active dock to correct for transverse relative motion between the vehicles. Acoustic, electromagnetic, and optical sensors provide position sensing redundancy in unpredictable conditions. The concept is being evaluated by building and testing individual components to characterize their performance, errors, and limitations, and then simulating the system to establish its viability at low cost.

The ALS project: lessons learned

In support of Canadian Forces transformation, Defence R&D Canada (DRDC) has established an ongoing program to develop machine intelligence for semi-autonomous vehicles and systems. Focussing on mine clearance and remote scouting for over a decade, DRDC Suffield has developed numerous UGVs controlled remotely over point-to-point radio links. Though this strategy removes personnel from potential danger, DRDC recognized that human factors and communications bandwidth limit teleoperation and that only networked, autonomous unmanned systems can conserve these valuable resources. This paper describes the outcome of the first autonomy project, Autonomous Land Systems (ALS), designed to demonstrate basic autonomous multivehicle land capabilities.

Safeguarding autonomy through intelligent shared control

This paper overviews the development and operator testing of a shared autonomy system for small unmanned ground vehicles operating in indoor environments. The project focused on creating driving assistance technologies to reduce the burden of performing low-level tasks when operating in cluttered or difficult areas by sharing control between the operator and the autonomous software. The system also provides a safety layer to prevent the robot from becoming disabled due to operator error or environmental hazards. Examples of developed behaviours include obstacle proximity warning, centering the vehicle through narrow doorways, wall following during long traversals, tip-over indicator, stair climbing aid, and retreat from communications loss. The hardware and software were integrated on a QinetiQ Talon IV robot and tested by military operators in a relevant environment.

Safeguarding teleoperation using automotive radar sensors

The Multi-Agent Tactical Sentry Unmanned Ground Vehicle, developed at Defence R&D Canada - Suffield, has been in service with the Canadian Forces for six years. This tele-operated wheeled vehicle provides a capability for point detection of chemical, biological, radiological, and nuclear agents. During the service life of this system, it has become apparent that a means of automatically detecting obstacles in tele-operated and semi-autonomous modes would greatly increase the safety and reliability of the vehicle in cluttered or human occupied operating environments. This paper documents the design of such a system based on a 24 GHz automotive radar.

Towards Framework-Based U×V Software Systems: An Applied Research Perspective

Defence R&D Canada changed research direction in 2002 from pure tele-operated land vehicles to general autonomy for land, air, and sea craft (U×V). The unique constraints of the military environment coupled with the complexity of autonomous systems drove DRDC to carefully plan a research and development infrastructure that would provide state of the art tools without restricting research scope.