Self-tuning algorithm for dsp-based motion control in cnc applications

This thesis describes the development of an adaptive control algorithm for Computerized Numerical Control (CNC) machines implemented in a multi-axis motion control board based on the TMS320C31 DSP chip. The adaptive process involves two stages: Plant Modeling and Inverse Control Application. The first stage builds a non-recursive model of the CNC system (plant) using the Least-Mean-Square (LMS) algorithm. The second stage consists of the definition of a recursive structure (the controller) that implements an inverse model of the plant by using the coefficients of the model in an algorithm called Forward-Time Calculation (FTC). In this way, when the inverse controller is implemented in series with the plant, it will pre-compensate for the modification that the original plant introduces in the input signal. The performance of this solution was verified at three different levels: Software simulation, implementation in a set of isolated motor-encoder pairs and implementation in a real CNC machine. The use of the adaptive inverse controller effectively improved the step response of the system in all three levels. In the simulation, an ideal response was obtained. In the motor-encoder test, the rise time was reduced by as much as 80%, without overshoot, in some cases. Even with the larger mass of the actual CNC machine, decrease of the rise time and elimination of the overshoot were obtained in most cases. These results lead to the conclusion that the adaptive inverse controller is a viable approach to position control in CNC machinery.

Casino Drink Policies: Limiting Third-Party Liability

In their efforts to provide an atmosphere or hospitality to their casino customers, many operators will provide complimentary alcoholic beverage service. This practice is fraught with liability, particularly in venues outside of Nevada. Conscientious operators must take every precaution to mitigate the possibility of lawsuit.

Adult Alternatives for Social Drinking: A Direction

In their survey/study - Adult Alternatives for Social Drinking: A Direction - by John Dienhart and Sandra Strick, Assistant Professors, Department of Restaurant, Hotel and Institutional Management, Purdue University, Dienhart and Strick begin with: “Changes in consumer habits have brought about a change in the business of selling alcoholic drinks and have impacted upon hotel food and beverage operations. The authors surveyed a sample of hotel corporate food and beverage directors to ascertain how they are handling this challenge.” Dienhart and Strick declare that the alcoholic beverage market, sale and consumption thereof, has taken a bit of a hit in contemporary society. “Even to the casual observer, it's obvious that the bar and beverage industry has undergone a great deal of change in the past few years,” say the authors. “Observations include a change in the types of drinks people are ordering, as well as a decrease in the number of drinks being sold,” they qualify. Dienhart and Strick allude to an increase in the federal excise tax, attacks from alcohol awareness groups, the diminished capacity of bars and restaurants to offer happy hours, increased liability insurance premiums as well as third-party liability issues, and people’s awareness of their own mortality as some of the reasons for the change. To quantify some empirical data on beverage consumption the Restaurant, Hotel, and Institutional Management Department of Purdue University conducted a study “… to determine if observed trends could be documented with hard data.” In regards to the subject, the study asks and answers a lot of interesting questions with the results presented to concerned followers via percentages. Typical of the results are: “When asked whether the corporation experienced a change in alcoholic sales in the past year, 67 percent reported a decrease in the amount of alcohol sold.” “Sixty-two percent of the respondents reported an increase in non-alcoholic sales over the past year. The average size of the increase was 8 percent. What Dienhart and Strick observe is that the decrease in alcoholic beverage consumption has resulted in a net increase for non-alcoholic beverage consumption. What are termed specialty drinks are gaining a foothold in the market, say the authors. “These include traditional cocktails made with alcohol-free products, as well as creative new juice based drinks, cream based drinks, carbonated beverages, and heated drinks,” say Dienhart and Strick by way of citation . Another result of the non-alcoholic consumption trend is the emergence of some novel marketing approaches by beer, wine, and spirits producers, including price increases on their alcohol based beverages as well as the introduction of faux alcoholic drinks like non-alcoholic beer and wine. Who or what is the big winner in all of this? That distinction might go to bottled water!

Beverage Ethics: Education for Alcohol Responsibility

The study looked at the processes in the development of an alcohol responsibility program for post-secondary students in the service management major at the University of Tennessee: he program has been certified by the State of Tennessee to satisfy the Alcohol Beverage Commission requirement for server training related to the handling and service of alcoholic beverages. A managerial viewpoint was adopted so as to provide the greatest benefit to service management graduate.