Automated mixed traffic transit vehicle microprocessor controller

An improved Automated Mixed Traffic Vehicle (AMTV) speed control system employing a microprocessor and transistor chopper motor current controller is described and its performance is presented in terms of velocity versus time curves. The on board computer hardware and software systems are described as is the software development system. All of the programming used in this controller was implemented using FORTRAN. This microprocessor controller made possible a number of safety features and improved the comfort associated with starting and shopping. In addition, most of the vehicle's performance characteristics can be altered by simple program parameter changes. A failure analysis of the microprocessor controller was generated and the results are included. Flow diagrams for the speed control algorithms and complete FORTRAN code listings are also included

An automated stall-speed warning system

The development and testing of a stall-speed warning system for the OV-1C was examined. NASA designed and built an automated stall-speed warning system which presents both airspeed and stall speed to the pilot. The airspeed and stall speed are computed in real time by monitoring the basic aerodynamic parameters (dynamic pressure, horizontal and vertical accelerations, and pressure altitude) and other parameters (elevator and flap positions, engine torques, and fuel flow). In addition, an aural warning at predetermined stall margins is presented to the pilot through a voice synthesizer. Once the system was designed and installed in the aircraft, a flight-test program of less than 20 hrs was anticipated to determine the stall-speed software coefficients. These coefficients would then be inserted in the system's software and then test flown over a period of about 10 hr for the purpose of evaluation

Advanced CO2 removal process control and monitor instrumentation development

A progam to evaluate, design and demonstrate major advances in control and monitor instrumentation was undertaken. A carbon dioxide removal process, one whose maturity level makes it a prime candidate for early flight demonstration was investigated. The instrumentation design incorporates features which are compatible with anticipated flight requirements. Current electronics technology and projected advances are included. In addition, the program established commonality of components for all advanced life support subsystems. It was concluded from the studies and design activities conducted under this program that the next generation of instrumentation will be greatly smaller than the prior one. Not only physical size but weight, power and heat rejection requirements were reduced in the range of 80 to 85% from the former level of research and development instrumentation. Using a microprocessor based computer, a standard computer bus structure and nonvolatile memory, improved fabrication techniques and aerospace packaging this instrumentation will greatly enhance overall reliability and total system availability

An improved artificial dendrite cell algorithm for abnormal signal detection

In dendrite cell algorithm (DCA), the abnormality of a data point is determined by comparing the multi-context antigen value (MCAV) with anomaly threshold. The limitation of the existing threshold is that the value needs to be determined before mining based on previous information and the existing MCAV is inefficient when exposed to extreme values. This causes the DCA fails to detect new data points if the pattern has distinct behavior from previous information and affects detection accuracy. This paper proposed an improved anomaly threshold solution for DCA using the statistical cumulative sum (CUSUM) with the aim to improve its detection capability. In the proposed approach, the MCAV were normalized with upper CUSUM and the new anomaly threshold was calculated during run time by considering the acceptance value and min MCAV. From the experiments towards 12 benchmark and two outbreak datasets, the improved DCA is proven to have a better detection result than its previous version in terms of sensitivity, specificity, false detection rate and accuracy

Fault diagnostic instrumentation design for environmental control and life support systems

As a development phase moves toward flight hardware, the system availability becomes an important design aspect which requires high reliability and maintainability. As part of continous development efforts, a program to evaluate, design, and demonstrate advanced instrumentation fault diagnostics was successfully completed. Fault tolerance designs for reliability and other instrumenation capabilities to increase maintainability were evaluated and studied

Automatic control of base cutter height on sugar cane harvesters

This thesis studies height estimation techniques necessary to achieve automatic control of the base cutter height on sugar cane harvesters and, in particular, those techniques analysing the hydraulic oil pressure drop across the base cutter hydraulic motor. Signal processing of pressure information leads to the proposal of pressure variance as a height quantifier. As harvesting conditions are non-stationary, an asymptotically unbiased variance estimator using an exponential data window and possessing adjustable tracking and noise smoothing characteristics is devised, implemented in a real-time microprocessor system and tested

Automated Plasma Spray (APS) process feasibility study: Plasma spray process development and evaluation

An automated plasma spray (APS) process was developed to apply two layer (NiCrAlY and ZrO2-12Y2O3) thermal-barrier coatings to aircraft gas turbine engine blade airfoils. The APS process hardware consists of four subsystems: a mechanical blade positioner incorporating two interlaced six-degree-of-freedom assemblies; a noncoherent optical metrology subsystem; a microprocessor-based adaptive system controller; and commercial plasma spray equipment. Over fifty JT9D first stage turbine blades specimens were coated with the APS process in preliminary checkout and evaluation studies. The best of the preliminary specimens achieved an overall coating thickness uniformity of + or - 53 micrometers, much better than is achievable manually. Factors limiting this performance were identified and process modifications were initiated accordingly. Comparative evaluations of coating thickness uniformity for manually sprayed and APS coated specimens were initiated. One of the preliminary evaluation specimens was subjected to a torch test and metallographic evaluation

Real-time fuzzy inference based robot path planning

This project addresses the problem of adaptive trajectory generation for a robot arm. Conventional trajectory generation involves computing a path in real time to minimize a performance measure such as expended energy. This method can be computationally intensive, and it may yield poor results if the trajectory is weakly constrained. Typically some implicit constraints are known, but cannot be encoded analytically. The alternative approach used here is to formulate domain-specific knowledge, including implicit and ill-defined constraints, in terms of fuzzy rules. These rules utilize linguistic terms to relate input variables to output variables. Since the fuzzy rulebase is determined off-line, only high-level, computationally light processing is required in real time. Potential applications for adaptive trajectory generation include missile guidance and various sophisticated robot control tasks, such as automotive assembly, high speed electrical parts insertion, stepper alignment, and motion control for high speed parcel transfer systems

Development of a programmable time-domain speech-synthesis system

ThesisSPEECH-SYNTHESIS - the artificial generation of that series of sounds known as 'speech' - has advanced beyond the novelty stage to become a real alternative to the simple audible and visible indicators and displays common to so much of modern society. There is very little that can be done with a light or buzzer that can't be done better with a 'spoken' word. 'Toys' such as Texas Instruments Speak and Spell have been recognized as effective learning tools. Through the electronic mouths of those machines, children are exposed to new words in an exciting and interactive way. Talking calculators (Williams, 1994: 67) and timepieces have expanded the horizons of the blind. Pilots and drivers are relieved of the need to watch their meters and gauges continuously as alarms can be given with instructions as to what actions should be taken. Speechsynthesis devices are finding a myriad of uses in communications, appliances, automotive applications, clocks, instrumentation, language translators etc. (Savon, 1982: 62). Despite the obvious advantages speech-synthesis provide, many systems are limited in their application possibilities due to one or more of the following disadvantages: • expensive • inflexible • difficult to program • limited to an Anglo-Saxon language • resultant speech is unnatural and 'mechanical' in nature • speech synthesizer is difficult to control and require a microprocessor . a thorough phonetic knowledge is a prerequisite for programming the syste

The Development of Synthetic Speech Aids for Patients With Acquired Disability

Patients suffering from a variety of speech disorders can benefit from synthetic speech. This study concentrates on the dysarthric patients with acquired speech loss as these patients have intact intellect and are more likely to benefit from synthetic speech. The physical skills of these patients vary enormously and their needs and situations are different. The main part of this work is concerned with the design, development and evaluation of a range of speech aids to meet these varying needs and skills. Three methods of speech synthesis are used and their performance has been investigated by using a Diagnostic Rhyme Test to measure the intelligibility of individual words. The results of this trial showed Adaptive Differential Pulse Code Modulation (ADPCM) to be more intelligible than Linear Predictive Coding (LPC), both these methods being more intelligible than constructive synthesis. A further trial was conducted to measure the speech quality of phrases produced by the synthesisers. This showed listeners preferred listening to phrases constructed of LPC words than to phrases generated using Phoneme based synthesisers. Phrases with mixed LPC and constructed words were preferred to phrases of constructed words. The devices that were developed use different methods of synthesis and the choice of method was guided by these trials. The Pocket Speech Aid is a rapid access limited vocabulary communication aid which uses ADPCM synthesis. Direct selection is the method used to give users access to eight phrases. The Pocket Speech Aid has been very successful in practice. When used as a telephone aid eight out of ten patients increased their communication ability and when used as a conversation prompter ten out of fourteen patients were able to steer the direction of real time conversations. This device has generated a great deal of interest from other centres and the demand for the device which is currently being manufactured confirms that it has a role to play in assisting those with communication difficulties. The Macleod Unit was named after a remarkable patient suffering from Motor Neurone Disease who realised his speech would soon be lost and had the foresight to select a vocabulary and record the words on a cassette recorder. His 625 word vocabulary was transferred to the speech aid which uses an encoding method of word selection. Clinical feedback showed the device to be of benefit for this highly motivated individual but was less successful for other patients in this group who found the cognitive effort to select codes too great. An unlimited vocabulary device based on the commercially available VOTRAX which uses constructive synthesis was developed but this device was rejected because of the robotic sounding voice. A further unlimited vocabulary device prototype, the Uvocom, was designed to improve the speech quality and to investigate if there is a need for an unlimited vocabulary. The Uvocom uses a core vocabulary of 1000 LPC words and uses Phoneme back-up for words not stored in the core vocabulary. Trials with the Uvocom have indicated that quality speech in an unlimited vocabulary device is likely to benefit a small number of patients who have the physical skills to operate such a device. Finally, some indication is given of the directions in which future work could progress based on the proven success of the Pocket Speech Aid