PERFORMANCE EVALUATION OF THE UT AUTOMATED ROAD MAINTENANCE MACHINE
This final report mainly focuses on evaluating the overall performance of the University of Texas' (UT's) Automated Road Maintenance Machine (ARMM). First, the ARMM's man-machine-balanced control loop was further developed then rigorously tested and evaluated based on (1) accuracy, (2) time, and (3) quality of the resultant seal. For the efficiency evaluation, thirty pavement crack images, which included longitudinal, transverse, and block cracking, were collected from a UT research campus, and field trials were completed at five locations (Austin, San Antonio, Dallas, Corpus Christi, and Travis County) in the state of Texas. Several additional significant improvements were made to the ARMM during the course of this project. Second, the ARMM's productivity was estimated based on (1) the results of the efficiency evaluation of the man-machine control loop, (2) observations made during the series of field trials, and (3) a productivity model. The mathematical model that predicts the productivity of the ARMM under various work conditions was developed as a means for job estimating and for rating the performance of the ARMM. The ARMM's estimated productivity was then compared with the typical productivity rate associated with conventional crack sealing methods. Evaluation results from the field trials and implementation recommendations are also made in this final project report. It was concluded that the introduction of automated methods to the pavement crack-sealing process will improve productivity and quality and can reduce costs and safety risks. The latter is a direct result of reducing normal crew sizes of seven to eight workers to only three to four workers. The reduction in crew size and the increase in productivity of the sealing process translate directly into significant potential cost savings. By automatically recording work completed, the ARMM should help improve project controls; by its ability to work at night, the ARMM should reduce road user costs.
A laboratory prototype of automatic pavement crack sealing based on a modified 3D printer
ABSTRACT Cracking is a common fault in asphalt and concrete pavements, which causes water damage and further defects if not repaired in timely fashion. Conventional pavement crack sealing methods based on machines and manual operations are generally subjective, labour-intensive, risky, and inefficient. A laboratory prototype of an automatic pavement crack sealing platform is proposed in this paper, which uses a modified three-dimensional (3D) printer and computer vision. A modified 3D printer based on fused deposition modelling (FDM) was combined with an image capturing platform, an image processing algorithm and a path planning method to form the automated pavement crack sealing platform, which can automatically detect pavement cracks and seal them with bitumen emulsion sealant. Specimens of concrete pavement slabs with cracks were produced in the laboratory to test the proposed method, and the cracks were then detected and sealed by the proposed platform. The results show that 3D printing is an effective method for automated pavement crack sealing, which is recommended in the field of automatic road maintenance and repair.
A remote manipulator for forestry operations
A remote manipulator was developed for forestry operations to relocate operators away from hazardous operations. The operations of tree trimming are performed in the vicinity of live electrical distribution lines, generating a hazard for the operator. The remote manipulator has two major subsystems: a three degree-of-freedom (DOF) aerial device acting as the main lifting arm, and a six DOF manipulator mounted at the end of the aerial device. Each arm was rate controlled with the reference rate provided by the displacement of a corresponding hand controller, which was kinematically equivalent to the manipulator. The mechanical design, the control system of the remote manipulator, and the results of field tests are described.<<ETX>>