11.1 Introduction
As previously discussed, the methods developed in this dissertation allowed the execution of telerobotic manipulation tasks by the combination of visual information using simple sensors and haptic force feedback to calculate assistive functions in real- time. In the current version of the telerobotic control system, the calculation of the assistive force for guiding the user's motion and the determination of the position and orientation of an object of interest as "seen" by the sensors (eye-in-hand camera and laser range finder) is based on a fixed reference frame located at the Puma 560 base. Having this system controlling a robot on a mobile platform with sensor-based assist functions such as the Wheelchair Mounted Robotic Arm (WMRA) may increase the flexibility of such system as an assistive device. This chapter describes potential research problems that the development of a real-time telerobotic control system with sensor-based assist functions for a robot-mobile platform would entail.
11.2 Combined Mobility and Manipulation with Time-dependant Sensory
Calibration Functions in Real-time
The idea is to design a real-time control scheme which combines the control strategies required for maximizing the combined mobility and manipulation capabilities as implemented in [72], and, at the same time, implement the time-dependent sensory
calibration functions required to calculate the sensor-based assist functions (SAF's) as described in this dissertation. The integration of a real-time telerobotic control system with sensor-based assist functions and the "Wheelchair Mounted Robotic Arm", WMRA, entails the implementation of optimized numerical approaches to deal with the redundancy of the WMRA system as well as the online calibration functions to determine the feedback force to guide the user's motion based on the sensor readings. Such development would benefit users who are vision-impaired and also forced to use a wheelchair.
11.3 Autonomous Navigation
The implementation of navigational technologies with advanced perception through the use of sensor fusion, autonomy and learning techniques might benefit from the development of a Hybrid-Deliberative Architecture (HDA). HDA techniques might provide a suitable solution when the environment can not be altered to accommodate the robot‟s needs. Behavior-based robotics and Neuro-Fuzzy techniques for inference and learning might be combined. In this scenario, Neural Networks (NN) might be extended to automatically extract fuzzy rules from sensory information (or numerical data) while Fuzzy Logic (FL) techniques might be used to resolve conflicts and control of primitive behaviors. Hybrid-Deliberative systems and methods are not commonplace and correspond to efforts of current research. Such implementation will require highly responsive and stable computer and software architectures. The multithreading framework developed for this work has the capabilities to perform in real-time and implements a high-level communication protocol to deal with different sensory input
formats (RS232, RS485, parallel, USB, IEEE1392, among others). These capabilities could serve as the foundation of the Hybrid-Deliberative approach.
11.4 Remote Assistance
As already implemented, the system provides force assistance based on the visual feedback and laser readings. A similar setup can be implemented with the added capability for monitoring of the WMRA from a remote location using communication channels over the Internet-based protocol. The sensory suite can be mounted at the end- effector of the wheelchair-mounted robot arm, similar to the current version of the Puma 560 testbed. The present user interface will have to be modified to accommodate the visual information from the optical sensors and the haptic graphical display interfaces to be available online to the remote assistant. This way the remote human user will be able to observe the environment around the WMRA. Using a haptic device as an input, the remote assistant can specify the desired motion to assist the disable person remotely. Several of the methods described in this thesis will be useful for this application.
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