NSF

The presentations and scientific discussion demonstrated that control engineering design and practice based on VSS and Sliding Mode may improve system performance in many critical applications, such as robotics, electric drives, automotive control, and machine tools. VSS is recognized as one of the important research directions in modern control theory. As the previous workshops VSS'98 was sucsessful in providing a forum for theoreticians and practicing engineers in automatic control to exchange ideas and share their perspectives, and for the young research investigators, particularly in US institutions, to have the opportunity to engage with the international VSS community. As for application aspects VSS'98 workshop was focused on automotive and engine control , electric drive and power converter systems which we considered to be of particular interests and great potential.

The program consisted of a plenary lecture and seven sessions:
Plenary presentation 'Sliding Sector for Variable Structure System' by K. Furuta and Yaodong Pan
Session 1. Discrete Time and Sampled Data Systems
Session 2. Nonlinear Systems
Session 3. Observers and Disturbance Estimators
Session 4. Applications
Session 5. Optimization and Computational Aspects
Session 6. Output Feedback Control
Session 7. Sliding Mode - Alternative Perspectives

Program Committee accepted the invitation of Professor Xinghuo Yu to organize the 6th International Workshop on Variable Structure Systems (VSS'00) in Australia prior to CDC'00 to be held there.

The main contributions of the workshop may be formulated as follows.

1. Design principles for the systems operating under uncertainties conditions.
New methods of designing nonlinear VSS were developed and reported:
second-order sliding mode control, disturbance estimation and their rejection,
combination of neural and fuzzy control with sliding mode approach, control of the systems with delay.

2. Discrete-time sliding mode control:
The major attention was paid to further development of 'sliding sector' method initiated by Professor K. Furuta and reported in his plenary presentation.

3. Chattering alleviation methods:
The main obstacle for sliding mode control implementation is high frequency oscillations called chattering. The efficient tools for chattering suppression based on nonlinear state observers and disturbance and parameter estimations were reported at the workshop.

4. Application results. New control strategies were developed for control of

- Electric drives and power converter,
- Flexible mechanical structures and robots,
- Variable geometry turbo-charged diesel engines,
- Chemical processes

The Workshop presentations were available in a Proceedings. Expanded versions of selected papers from VSS'99 have been published in the book