1、PDF外文：http:/ of Voice Recognition for Control of a Robotic Welding Workcell ABSTRACT: This paper describes work underway to evaluate the effectiveness of voice recognition systems as an element in the control of a robotic welding workcell. Factors being considered for control include program e
2、ditor access security,Preoperation checklist requirements, welding process variable control,and robot manipulator motion overrides. In the latter two categories, manual vocal control is being compared against manual tactile control and fully automatic control in terms of speed of response, accuracy,
3、 stability, reliability. And safety. Introduction Voice recognition technology is now recognized as a potential means for easing the workload of operators of complex systems. Numerous applications have already been implemented, are in various stages of development, or are under conside
4、ration. These include data entry,control of aircraft systems, and voice identification and verification for security purposes. Voice control has also been proposed for use aboard the space station. One prime area for application would be control of some functions of robots used for intraand extraveh
5、icular inspection, assembly, repair,satellite retrieval, and satellite maintenance when a crewmember is serving in a supervisory capacity or the system is operating in a teleoperation mode. Voice control of sensors and process variables would free the crewmembers hands for other tasks, such as direc
6、t control or override of the manipulator motion. Similarly, the workload associated with control of many onboard experiments could be eased through the use of this technology. This paper describes the application of voice recognition for control of a robotic welding workcell. This is a complex syste
7、m involving inputs from multiple sensors and control of a wide variety of robot manipulator motions and process variables. While many functions are automated, a human operator serves in a supervisory capacity, ready to override functions when necessary. In the present investigation, a commercially a
8、vailable voice recognition system is being integrated with a robotic welding workcell at NASA Marshall Space Flight Center, which is used as a test bed for evaluation and development of advanced technologies for use in fabrication of the Space Shuttle Main Engine. In the system under development, so
9、me functions do not yet have automatic closedloop control, thus requiring continuous monitoring and real-time adjustment by the human operator. Presently, these ovemdes are input to the system through tactile commands (；.e. pushing buttons. turning knobs for potentiometers, or adjusting mechanical d
10、evices). Since the operator monitors the process primarily visually, he must either look away from the process to find the proper button or knob or rely on“muscular memory”much as a touch-typist does. In the first case, the time of response to a deviant condition may be excessive. In the second case
11、, there is an increased probability of a secondary error being introduced by the operator. A voice recognition system could reduce the response time required from the operator.The probability of pushing the wrong button should similarly be reduced. Also, operator fatigue should be minimized. Since t
12、he operator can continuously monitor the process during override input, the effect of the change can be observed more quickly. Thus, if the desired value is exceeded and reverse correction is required, it should be accomplished more quickly, allowing less overshoot. This reduction in oscillation abo
13、ut the desired value makes the system more stable. Another factor that can be improved is operator safety. In a safety-critical situation,the robots operation can be halted immediately by use of the “emergency stop, or E-stop, mode, which is initiated, conventionally, by depressing a large button. I
14、f an operator inadvertently finds himself in a hazardous situation, it may be necessary for him to initiate the E-stop sequence. Should the operator not be within reach of the button,however, he may be unable to take the necessary action, and, as a result, could suffer serious injury. Having the cap
15、ability of stopping the robot by issuing a voice command could significantly improve the operators safety by enabling him to stop the robot even when not within reach of the E-stop button. Manual corrections are occasionally required to adjust the location at which the weld filler wire enters the weld pool. Proper entry location is absolutely critical to sound weld quality. Adjustments are made either by manually adjusting mechanisms that hold the
