Robotics Reports
Adaptation of Wheeled Mobile Robots to Highway Maintenance Operations
Kochekali, Homayun, and Steven A. Velinsky, "Adaptation of Wheeled Mobile Robots to Highway Maintenance Operations", UCD-ARR-94-01-05-01, 27 pp, January,1994.
Abstract — This paper reviews the important research and development activities in the subject of Wheeled Mobile Robots (WMRs), in order to evaluate their potential use in highway maintenance and construction tasks. It particularly focuses on mobility as an essential feature for highway maintenance and construction application, which concerns wheel type arrangement, kinematics, dynamics, navigation and control. For each of these areas, aspects related directly to the deployment of WMRs in highway maintenance are discussed.
Applications of Telerobotics to Highway Maintenance
Hsia, Tien C., Andrew A. Frank, Gregory D. Benson, and Robert Cobene, "Applications of Telerobotics to Highway Maintenance", UCD-ARR-93-06-07-01, 130 pp, June, 1993.
Abstract — This report covers telerobotics studies from the perspective of highway maintenance automation conducted in the UC Davis Robotics Research Laboratory over the last fourteen months. Here we document the four project objectives. First, we explore the current field of telerobotics to understand the underlying principles and current technology. Second, we examine the feasibility and benefits of telerobotics application. Third, we survey an array of "off the shelf" products that can be incorporated in a highway maintenance telerobotic system. Finally, we document the design and developement of our telerobotics testbed that demonstrates the utility and feasibility of telerobotics for highway maintenance and to provide practical experience with the development process. The report is concluded with a recommendation of future research and development of a mobile telerobotic system for man-in-the-bucket maintenance operations.
Control System Development for Tethered Mobile Robot for Automating Highway Maintenance Operation
Hong, Daehie, "Control System Development for Tethered Mobile Robot for Automating Highway Maintenance Operation", UCD-ARR-94-09-12-01, 159 pp, September, 1994.
Abstract — A new concept, the use of a self-propelled mobile robot working in close proximity to a support vehicle for purposes of power, materials, etc., has been proposed for highway maintenance operations which require positioning equipment within close proximity to a support vehicle and almost always demand an end-effector to follow a specific path with precise path following requirements. This mobile robot system has been termed the Tethered Mobile Robot (TMR), and such an approach has the potential of use in a wide variety of applications as a positioning module. This report discusses the control system development of the TMR including various tracking control modes and controller hardware for their implementation.
A new non-linear path tracking control algorithm for a 2 DOF differentially steered mobile robot is presented and its exponential stability is proved. There have been no papers that have applied the feedback linearization for non-holonomic mobile robot control problem due to non-square nature of its equations of motion. A new idea is proposed to overcome the inherent problem and an exponentially stable non-linear control law is successfully derived using the feedback linearization.
In the TMR control, the biggest concerns are the non-linear terms due to centrifugal force and routing force that is very hard to estimate. However, the upper and lower bounds of the fluctuating routing force can be determined using an appropriate experimental method. Therefore, the robust control using the sliding mode technique is appropriate to the TMR control problem. The sliding mode control for wheeled mobile robot is formulated and this is a unique control strategy for the TMR and general wheeled mobile robot.
To implement the developed algorithms, a new mobile robot controller is optimally designed using 80486 CPU and the motor controller equipped with the Flexible Servo Controller (FSC). The motor controller board is fabricated with the Printed Circtui Board CAD. This motor controller is the first application of the FSC chip. The TMR controller has unique features utilizing the advantages of the developed servo motor controller.
Description and Operational Instructions of the Demo TMRR
Hong, Daehie, Keith J. Mueller, James M. Stiles, and Steven A. Velinsky, "Description and Operational Instructions of the Demo TMRR", UCD-ARR-97-01-31-01, 43 pp, January 1997.
Abstract — The Tethered Mobile Routing Robot (TMRR) has been developed as a general crack sealing machine that will sense, rout, and seal both longitudinal and transverse cracks in a given workspace located behind a support vehicle. This robot has been developed by the Advanced Highway Maintenance & Construction Technology Research Center at the University of California at Davis. The full sized TMRR weighs approximately 4400 N [1000 1b.] and requires power from a large support vehicle. Due to its size, it was deemed infeasible to transport the large TMRR to trade shows and conferences. A demo TMRR was constructed for the express purpose to demonstrate capabilities and special design features of the larger version. This report describes its mechanical and control structure, and also includes operational instructions.
Development Of A Tethered Mobile Robot (TMR) For Highway Maintenance
Winters, Scott E., and Steven A. Velinsky, "Development Of A Tethered Mobile Robot (TMR) For Highway Maintenance", UCD-ARR-92-11-25-01, 107 pp, November, 1992.
Abstract — Many highway maintenance operations, in addition to tasks in numerous other industries, involve the use of materials and tooling within close proximity to a support vehicle. For example, highway crack sealing operations involve maintenance personnel dispensing sealant from a wand which is attached to a vehicle housing the sealant melter. Other operations involve the use of tools which are powered by a supply on the support vehicle, such as painting equipment, etc. While the use of conventional robots to automate these operations seems at first consistent with many of the positional requirements of maintenance tasks, their use is hindered due to several reasons. First and foremost, commercial robots have a relatively low load carrying capacity relative to their weight. Considering the weight of many road maintenance devices, such as routers, and the forces that occur during their operation, the use of conventional robot/end effectors is not possible. Highway maintenance activities almost always require an end-effector to follow a specific path as opposed to merely moving from one location to another without path-following requirements as in most manufacturing automation applications. Another aspect relates to the fact that most highway maintenance operations require the placement of the device within a specific height relative to the pavement (e.g., paint nozzles, routers, etc.), which additionally complicates the use of conventional robots.
In order to overcome the inherent disadvantages of the use conventional robots for the above tasks, an unique concept has been developed. This concept is the use of a self-propolled robot working in close proximity to a support vehicle for purposes of power, materials, etc., and allowing for the measurement of these robot's position relative to the support vehicle with high accuracy. The purpose of this thesis is to conceptually develop the Tethered Mobile Robot (TMR). In addition to presenting the conceptual TMR system layout, a simple prototype was built and tested to prove validity.
Development of a Tethered Mobile Robot for Highway Maintenance
Velinsky, Steven A., Daehie Hong, and Keith A. Mueller, "Development of a Tethered Mobile Robot for Highway Maintenance", UCD-ARR-94-10-31-01, 121 pp, October, 1994.
Abstract — This document reports on the development of the Tethered Mobile Robot (TMR) at the Advanced Highway Maintenance and Construction Technology (AHMCT) Center at the University of California, Davis. This application of automation has the primary objective of improving the level of safety of a variety of highway maintenance and construction activities.
The TMR system is a self-propelled wheeled mobile robot that works in close proximity to a support vehicle for purposes of power, etc. The robot's position relative to the support vehicle is measured with high accuracy. As such, the support vehicle contains the associated maintenance supplies (sealant, etc.), power supply (hydraulic power supply, electrical generator, etc.), and in many cases, the primary maintenance operation sensing devices (e.g., machine vision for crack sealing operations) and/or path planning components.
The TMR project has involved the following: a detailed literature search, development of global machine specifications, development of system design concepts, and the design and construction of a downsized prototype TMR for the initial development of both the mechanical system and the required controls. This was followed with the evaluation of the first generation prototype, which led to the design and construction of a full-sized prototype TMR and relative position system. This report addresses each of the development aspects, and includes discussions of operational requirements, system configuration, system modeling, downsized system testing, control system architecture and approach, and test results of the full-size unit. Technical drawings are included as are control software listings. Finally, recommendations for further work are discussed.
Development of Tethered Mobile Routing Robot (TMRR)
Hong, Daehie, James M. Stiles, Keith J. Muller, and Steven A. Velinsky, "Development of Tethered Mobile Routing Robot (TMRR)", UCD-ARR-97-02-24-01, 194 pp, February 1997.
Abstract — This report describes the development of a new wheeled mobile robot aimed at automating the crack preparation and sealing process. This robot is a differentially steered wheeled mobile robot with centrally located router and articulated sealant head. Additionally, a laser range sensor is installed from the front of the robot to allow for automated crack following. The sensor is slide mounted to provide the necessary field of view. A support vehicle provides all power and materials through the use of a tether, and also contains a vision based sensing system for crack identification. The robot position relative to the support vehicle is thus necessary, and it is accurately measured through a cable extension transducer based system. This mobile robot is referred to as the Tethered Mobile Routing Robot (TMRR). This report includes the descriptions of this unique mobile robot system and also operational instructions.
Dual-Arm Cam-Lock Manipulator
Meghdari, Ali, "The Dual-Arm Cam-Lock Manipulator", UCD-ARR-94-01-31-02, 38 pp, January, 1994.
Abstract — This report presents the conceptual design and technical specifications of a novel robotics sytem termed the Dual-Arm Cam-Lock Manipulator. It was designed on the basis of variable geometry, rigidity, and workspace. It has the ability to adjust its multi-arm structure in a compact configuration, making it suitable for applications requiring mobility. A telerobotics application of cam-lock manipulators has been proposed for bridge inspection and maintenance. Technical papers prepared on this subject have been accepted for presentation and publication at the 1994 ASCE SPACE Conference on Robotics for Challenging Environments, and the 1994 IEEE International Conference on Robotics and Automation. In addition, an invention patent application has been filed with the Office of Technology Transfer of the University of California.
Dynamic Modeling of Wheeled Mobile Robots
Boyden, Demick, and Steven A. Velinsky, "Dynamic Modeling of Wheeled Mobile Robots", UCD-ARR-93-10-05-01, 80 pp, October, 1993.
Abstract — A significant amount of research is being done and has been published on the subject of wheeled mobile robots (WMR's). A great deal of this work is dedicated toward the development of control strategies for tracking WMR's and for the generation of path planning techniques (mostly for the purposes of collision avoidance). A fundamental part of any research in this area involves some way to track the WMR's position and orientation. Most researchers have used kinematic models to accomplish this task arguing that because of low speeds, low accelerations, and lightly loaded conditions under which WMR's operate, these kinematic models are valid. However, as we advance to the future of WMR's, dynamic modeling of these vehicles becomes increasingly important as wheeled mobile robots are designed to perform heavy duty work and travel at higher speeds.
This research investigates the importance of dynamic modeling of differentially and conventionally steered wheeled mobile robots. The Tethered Mobile Robot (TMR) designed for the purposes of automated crack sealing operations is the vehicle which is modeled and simulated in this work. In this paper, a dynamic model including an accurate tire representation is developed for both differentially and conventionally steered TMR's. In addition to these dynamic models, kinematic and simplified dynamic models are also developed for each of the TMR configurations. The simplified dynamic model utilizes greatly simplified tire representations instead of the complex tire model used by the dynamic model. Through the use of simulation, the limits of validity of each of the models is found for the purposes of determining which model is appropriate for a given application. Additionally, the accuracy of the dead reckoning vehicle tracking process is investigated.
Generalized Telerobotic Hand Controller for Force Reflection
Long, Gregory L., and Curtis L. Collins, "A Generalized Telerobotic Hand Controller for Force Reflection", UCD-ARR-93-03-01-01, 44 pp, March, 1993.
Abstract — Future strategies for environmental clean-up and hazardous waste removal will rely primarily on remote manipulation and sensing. Remote manipulation via a computer controlled elector-mechanical system is known as telerobotics. With increased computational power and sophisticated programming languages, the addition of high-performance generalized hand controllers has expanded the versatility of telerobotic systems.
This report describes various components of a newly developed generalized telerobotic hand controller. The hand controller was designed and fabricated in the Robotics Laboratory at the University of California, Irvine. While these efforts have focused primarily on the feasibility of new telerobotics technology, attention has been given to potential commerical applications.
Modeling and Control of Mobile Manipulators
Chung, Jae H., "Modeling and Control of Mobile Manipulators", UCD-ARR-97-02-15-01, 127 pp, February 1997.
Abstract — A mobile manipulator is a robotic manipulator mounted upon a wheeled mobile platform. In recent years, interest in the area of mobile manipulators has increased significantly because of the mobility combined with the manipulation. Although significant amounts of research and development have been performed in the area of nonholonomic control of mobile robots and in the area of motion control of robotic manipulators, there is only limited literature available on control of mobile manipulators which combine those two functions.
There are several issues that contribute to the uniqueness of the mobile manipulator modeling and control problem. First, a weekend mobile platform is subject to nonholonomic constraints. Therefore, the mobile manipulator which consists of a wheeled mobile platform and a robotic manipulator is also subject to nonholonomic constraints. Second, kinematic redundancy is created when a mobile platform and a multi-link manipulator are combined. Third, the mobile platform and the manipulator dynamically interact with each other.
This report is concerned with the modeling and control of mobile manipulators. The Lagrange-d'Alembert formulation is used to obtain a concise description of the dynamics of the system. Then, the solvability of tracking problems for a non-redundant mobile manipulators is investigated by using static input-output linearization. Then, the complexity of the model is increased by introducing kinematic redundancy which is created when a multi-linked manipulator is used. The kinematic redundancy is resolved by decomposing the mobile manipulator into two subsytems: the mobile platform and the manipulator. Based on the redundancy resolution scheme, the nonlinear interaction control algorithm, in which the suitable controllers are designed for the two subsystems, is developed and applied to the redundant mobile manipulator.
When ideal kinematic constraints are violated due to wheel slip, modeling of wheeled mobile robots using a Lagrange-d'Alembert formulation is not valid. The wheel slip is modeled as a disturbance to the system and the tracking performance of the interaction controller is investigated in the presence of this disturbance.
Teleoperated and Automated Maintenance Equipment Robotics (Phase I)
Sun, Z., Sonja, Jim Mehlschau, Nelson Smith, Keith Kruetzfeldt, Paul Chen, Andrew Frank, and Tsusuan Chang, "Teleoperated and Automated Maintenance Equipment Robotics (Phase I)", UCD-ARR-94-09-30-01, 124 pp, September, 1994.
Abstract — In an attempt to eliminate the operator's exposure to the hazards associated with highway maintenance, University of California at Davis in conjunction with FMC under a grant from California Department of Transportation (CalTrans) has developed a teleoperation system (remote control package) for a front-end loader. The radio remote control system developed enables the front-end loader to be operated remotely by current CalTrans workers performing a full range of functions at a distance up to 300 ft (91 meters). Operating modes can be easily shifted from remote mode to on-board mode or vice versa. The system has proven to be reliable, durable, safe, and sufficiently easy to operate. The performance of the remotely operated loader is equivalent or better than that of the conventional on-board manually operated machine.
The feasibility of teleoperating an unmanned highway maintenance equipment has been well demonstrated. It is concluded that the remote control package is ready for commercialization and can be easily adapted to general purpose heavy equipment and other mobile machinery.
Recommendations for further study include the integration of telepresence technology and other feedback systems into the remote control package along with capability for teachable automatic functions to enhance productivity of the front-end loader for both remote and on-board operation. Study of human factors related to teleoperation of a highway maintenance vehicle equipped with feedback systems is also desired.
Teleoperated and Automated Maintenance Equipment Robotics, Phase II
Kruetzfeldt, Keith, Z. Sonja Sun, Nelson Smith, Jim Mehlschau, Andrew Frank, and Paul Chen, "Teleoperated and Automated Maintenance Equipment Robotics, Phase II", UCD-ARR-95-06-30-01, 47 pp, June, 1994.
Abstract — Sensory feedback has been discovered to be extremely important in teleoperation of highway maintenance vehicles such as a front-end loader, where the vehicle must be navigated over unfamiliar and very rough terrain while simultaneously performing bucket operation. The primary means of feedback in this investigation for control of a remote vehicle is through use of a transmitted three dimensional video image used to duplicate the operator's on-board visual environment. This paper discusses and evaluates audio and video human feedback systems for use in the control of remotely operated heavy highway maintenance equipment. A three dimensional color video/audio feedback system was integrated into the teleoperated front-end loader which was developed during Phase I of the TAMER project. Performance comparisons are made between in-vehicle operations and teleoperations using line-of-sight, two dimensional, and three dimensional video feedback systems coupled with a simple monaural audio feedback system. Camera mounting and control systems, and field of view requirements are also evaluated. Suggestions for improvements to the system are based on field trials of the complete teleoperated front-end loader and audio/visual feedback system.
Telerobotics for Highway Maintenance and Construction
Meghdari, Ali, and Bahram Ravani, "Telerobotics for Highway Maintenance and Construction", UCD-ARR-94-02-10-01, 40 pp, February, 1994.
Abstract — The maintenance and construction activities of the California Department of Transportation (Caltrans) have been thoroughly studied, and a summary of such activities are tabulated and presented in this report. In addition, a brief overview of the Telerobotics concept is presented. The possibilities of applying Telerobotics to highway maintenance and construction tasks have been explored. In particular cases, proper recommendations are made. Finally, as a part of this study, a new class of robot manipulators, termed the "Dual-Arm Cam-Lock Manipulator", were designed on a mobile platform for possible applications in bridge inspection and maintenance.
Theoretical Framework For Design of Robotic Fixtures
Nederbragt, Walter W., "A Theoretical Framework For Design of Robotic Fixtures", UCD-ARR-97-02-01-01, 126 pp, February 1997.
Abstract — The relative location of a robot's end-effector to objects in the robot's workspace is sometimes unknown. Tactile sensing fixtures, when used with a touch probe attached to the robot, can determine the relative location of these objects. Currently, the work on the design of tactile fixtures for this purpose has been limited. This dissertation addresses this issue by creating a theoretical framework for the design of tactile fixtures. In this framework, fixtures are analyzed based on the geometric surfaces that compose them and the contacts that are made to them.
The analysis of fixtures based on their geometric surfaces relies upon the Euclidean group and its subgroups. Using these groups, several propositions are introduced and proven. These propositions form the basis of a new theory that can aid in the design of touch sensing fixtures by analysis of the continuous and finite groups that represent them. Using these propositions, fixtures involving different geometric elements are analyzed for their usefulness in determining the relative position between two bodies.
This analysis is taken one step further by looking at contacts needed to make a "useful" reference fixture. Contacts between spheres, planes, cylinders, points, and lines are studied, and group representations are found for every possible contact that could exist between these geometric elements. Using the group representations, all possible combinations of contacts are studied. During this enumeration, 17,465 "useful" contact combinations are found.
Finally, using the information obtained from the contact analysis, two simple yet novel touch sensing fixtures for referencing are developed. One of those fixtures uses a plane-cylinder geometry to uniquely locate a frame. The other fixture uses a tripod shaped probe and a planar surface (in the final design a digitizer is used) to uniquely locate a reference frame.
Tracking Control Algorithms for the Tethered Mobile Robot
Zhang Yulin, and Steven A. Velinsky, "Tracking Control Algorithms for the Tethered Mobile Robot", UCD-ARR-94-06-30-01, 143 pp, June, 1994.
Abstract — The purpose of this research is to provide a theoretical basis for the tracking control of a Tethered Mobile Robot in highway maintenance applications. The Tethered Mobile Robot is a mobile robot with two independent driven wheels. The tracking control algorithms for this type of mobile robot are thoroughly and systematically studied in this report. The tracking control algorithms are developed both on the basis of kinematic models and dynamic models. The main effort is to develop tracking control algorithms with strong robustness to uncertainties, such as system perturbations and external disturbances.
From a tracking control point of view, the Tethered Mobile Robot is no more than a ground vehicle with two independent driven wheels. As such, the tracking control algorithms presented in this report are valid for any differentially steered wheeled mobile robots or vehicles.
Robotic Maintenance for Automated Highway Systems: Economic Analysis
Alex Stroup and Steven A. Velinsky, "Robotic Maintenance for Automated Highway Systems: Economic Analysis," Advanced Highway Maintenance and Construction Technology Research Center, UCD-ARR-94-09-27-01, September, 1994.
Abstract:
The cost of congestion on major highways has become very high indicating the need for increased highway capacity and resulting in the conceptual development of automated highway systems. Although much research is ongoing concerning the manner in which automated highways should operate and how they should be implemented, there has been minimal investigation concerning construction and maintenance requirements. As the demand and performance of the highway increases, the impact of maintenance and construction operations will in turn be more dramatic. Therefore, the need for improved maintenance and construction techniques is vital to the success of the high capacity AHS.
As existing highway systems deteriorate, labor costs have increased, resulting in the need and development of more efficient and safer highway maintenance techniques using automation and robotics. Automated systems have been successfully developed to perform various maintenance tasks such as crack sealing. Research in the field of automated road maintenance and construction has shown that there is significant potential for cost saving due to increased efficiency, increased safety, and fewer traffic delays.
A model to estimate the cost benefits of robotic construction and maintenance for automated highway systems is developed in this report. The analysis considers the direct costs to the transportation agency or contractor and the user costs to the driving public. Direct costs are associated with equipment, labor, and material costs. User costs are due to increased traffic congestion resulting from highway maintenance operations. The computer model was developed to quantify the benefits associated with the automation of a particular maintenance task. Case studies of magnetic markers installation and pavement repairs were performed and results are given.
