A Unified Framework for Robust Parameter Varying Control with Applications to Engine Control Problems

这项研究项目涉及分析、设计和实现非线性系统的鲁棒控制器，例如在可变条件下运行的内燃机。现代车用内燃机的运行必须满足经济、环境、社会和市场因素施加的各种相互冲突的限制，例如：将尾气排放控制在接近零的水平以满足政府标准，提供与消费者接受的一致的更高的燃油经济性，在各种运行条件下保持令人满意的车辆性能，以及在车辆的整个使用寿命内安全可靠地运行。目前还没有统一的控制方法来为具有时滞、饱和约束和大运行参数变化的非线性系统提供鲁棒控制器。此外，由于现代控制器是在数字微处理器中实现的，与这些控制器的可实现性相关的问题是必不可少的，但往往被忽视。硬件的限制和实时计算的限制要求低阶数字控制器的实现。这项研究项目解决了现代控制理论的重要和具有挑战性的缺陷和局限性。基于最近发展的鲁棒增益调度控制、定阶控制采样数据系统、交替投影算法和线性矩阵不等式法，开发了新的工具。以康明斯发动机公司提供的柴油机模型为设计范例，验证了所开发技术的适用性。康明斯已同意通过提供行业专业知识、模拟模型、测试数据和访问他们的实验测试设施来与调查人员密切合作。研究结果为以统一高效的计算方式控制发动机、机器人和制造过程等一大类实际控制工程问题提供了有价值的见解和优化设计方法。

This research project deals with the analysis, design,and implementation of robust controllers for nonlinear systems such as operating under variable conditions such as internal combustion IC engines. The operation of modern IC engines for automotive use must satisfy a diverse range on conflicting constraints imposed by economical, environmental , societal and marketing factors, such as; regulating exhaust emissions to near zero levels to meet government standards, providing increased fuel economy consistent with consumer acceptance, maintaining satisfactory vehicle performance over a wide range of operating conditions, and performing safely and reliably over the life of the vehicle. At the present time there exists no unified control methodology to provide robust controllers for nonlinear systems with time-delays, saturation constraints and large operating parameter variations. In addition, since modern controllers are to be implemented in a digital microprocessor, issues related to the implementability of these controllers are essential, but are often ignored. Hardware limitations and real-time computational constraints require the implementation of low-order digital controllers. This research project addresses the important and challenging short comings and limitations of modern control theory. Novel tools based on recently developed robust gain-scheduled control, fixed-order control sampled-data systems, alternating projection algorithms and linear matrix inequality methods are developed. The model of a diesel engine, provided by Cummins Engine Company, is used as a design paradigm to demonstrate the applicability of the developed techniques. Cummins has agreed to collaborate closely with the investigators by providing industrial expertise, simulation models, test data, and access to their experimental test facilities. The research results provide valuable insight and optimized design methodologies to control a large class of practical control engineering problems,such as engines, robots and manufacturing processes in a unified and computationally efficient manner.