A Classification and regression trees (CART) model of parallel structure and long-term prediction prognosis of machine condition

This paper presents a combined prediction model involving the parallel of classification and regression trees (CART) model, namely p-CART, and a long-term direct prediction methodology of time series techniques to predict the future stages of the machine’s operating conditions. p-CART model consists of multiple CART models which are connected in parallel. Each sub-model in the p-CART is trained independently. Based on the observations, these sub-models are subsequently used to predict the future values of the machine’s operating conditions separately with the same embedding dimension but the different observations’ indices. Finally, the predicted results of sub-models are combined to produce the final results of the predicting process. Real trending data acquired from condition monitoring routine of low methane compressor are employed for evaluating the proposed method. A comparative study of the predicted results obtained from traditional CART and p-CART models is also carried out to appraise the prediction capability of proposed model. In addition, a further improvement in predicting capability of p-CART is proposed to ameliorate the accuracy and efficiency of this method

Generic transition management for reconfigurable hybrid control systems

Complex control systems often contain numerous controllers (or control laws) for a given plant, where the controller having authority at any given time depends on the current operating condition of the plant. For example, a plant operating in the nominal condition generally uses one controller, while a plant with a fault uses a different controller. Even in nominal operation, there may be several controllers that are designed for different steady-state operating points (for example, a helicopter may have one controller for hover and a different one for take-off). These types of systems can be modeled as hybrid systems, that is, systems that have both continuous and discrete states. In this case, the plant and the controllers can be modeled using differential or difference equations, which have continuously-varying states. The higher-level logic that determines which controller to use can be modeled using discrete states that evolve according to a finite state automaton. The implementation of hybrid controllers can be facilitated by using component-based software architectures [1], [2], which reduce software development and validation costs. Component-based architectures encourage code reuse across applications. For example, there are many algorithmic methods that are applicable to many different systems – neural networks

A pattern for gradual transitioning during dynamic component replacement in extreme performance UAV hybrid control systems

A common strategy for control systems is to design a set of controllers for a given plant (i.e., the system to be controlled). The controller that is chosen to be implemented at any given time depends on the current operating condition of the plant. For example, a plant operating in nominal condition generally uses one controller, while a plant with a fault uses a different controller. The predefined controllers are usuall

A hierarchical controller for the subscale thermal control system of the space station

Issued as User manual, Project no. E-21-651User manual has title: A hierarchical controller for the subscale thermal control system of the space stationUser manual has co-authors: Lewis, Frank; Davey, Kent; Cheng, Jim, and Shyy, Dong-Jy

Rapid prototyping of transition management code for reconfigurable control systems

This paper presents a rapid prototyping technique that focuses on transition management in hybrid systems. In particular, it integrates hybrid modeling and simulation (for specifying and validating transition strategies) with a generic transition management pattern built on a Real-Time CORBA-based platform for reconfigurable control systems. Code generation is performed from the hybrid models to transition management code. This allows hybrid systems and their reconfiguration strategies to be prototyped and validated at an early stage in development and for the strategies to be directly transferred into the control system software without a separate, manual reimplementation step. The application of this work is found in most complex control systems, including the control of unmanned aerial vehicle (UAVs) performing extreme maneuvers, which is our driving application area.