A thruster assisted position mooring system includes different control functions for station keeping and motions damping of the horizontal-plane motions. A new nonlinear passivity-based state observer producing the th...
详细信息
A thruster assisted position mooring system includes different control functions for station keeping and motions damping of the horizontal-plane motions. A new nonlinear passivity-based state observer producing the thruster control actions has been implemented and verified in full-scale tests. Even though sophisticated filtering and control techniques are applied in the high-level controlsystems, unforeseen load peaks caused by process disturbances acting on the local actuation system may challenge the power plant stability, if no proper precaution is taken. Both high and low level control aspects concerning integrated positioning and electrical propulsion system are addressed.
We proposed a decentralized control algorithm of multiple robots handling a single object in coordination. The motion command of the object is given to one of the robots, referred to as a leader, and the other robots ...
详细信息
We proposed a decentralized control algorithm of multiple robots handling a single object in coordination. The motion command of the object is given to one of the robots, referred to as a leader, and the other robots referred to as followers estimate the motion of the leader by themselves through the motion of the object and handle the object based on the estimated reference. In this paper, the proposed control algorithm is experimentally applied to three omnidirectional mobile robots with three degrees of freedom of motion, and the results illustrate the validity of the proposed control algorithm.
This paper describes an application of unfalsified control theory to the design of an adaptive controller for a nonlinear robot manipulator. A nonlinear `computed torque' control structure is employed. Four parame...
详细信息
This paper describes an application of unfalsified control theory to the design of an adaptive controller for a nonlinear robot manipulator. A nonlinear `computed torque' control structure is employed. Four parameters representing unknown masses, inertias and other dynamical coefficients are adaptively adjusted in real-time using an linear programming technique to optimally satisfy control-law unfalsification conditions. Simulations show that the method yields significantly more precise and rapid parameter adjustments than conventional continuous parameter update rules, especially when the manipulator arm is subject to sudden random changes in mass or load properties.
The paper investigates improvements in the turbocharged diesel engine transient response that can be attained when a turbocharger power assist system, consisting, for example, of an electric motor and a battery, is co...
详细信息
The paper investigates improvements in the turbocharged diesel engine transient response that can be attained when a turbocharger power assist system, consisting, for example, of an electric motor and a battery, is coupled to the turbocharger shaft. The method of investigation relies on formulating and solving numerically an appropriate minimum time optimal control problem. Comparison with a conventional turbocharged diesel engine response reveals the mechanism by which acceleration improvements are attained while maintaining high fuel efficiency and equivalent smoke emission levels. A feedback controller that generates responses qualitatively similar to the optimal ones is also described.
In this paper we develop a globally stabilizing stability-based switching controller strategy for a three-state lumped parameter centrifugal compressor surge model. The proposed model involves pressure and mass flow c...
详细信息
In this paper we develop a globally stabilizing stability-based switching controller strategy for a three-state lumped parameter centrifugal compressor surge model. The proposed model involves pressure and mass flow compression system dynamics as well as spool dynamics to account for the influence of speed transients on the compression surge dynamics. The proposed nonlinear switching controller architecture involves throttle and compressor torque regulation and is directly applicable to compression systems with actuator amplitude and rate saturation constraints.
Recently, a new version of the TCP mechanism, called TCP Vegas, is proposed, and has potential to achieve better performance than current mechanisms such as TCP Tahoe and Reno. This paper considers a window-based flow...
详细信息
Recently, a new version of the TCP mechanism, called TCP Vegas, is proposed, and has potential to achieve better performance than current mechanisms such as TCP Tahoe and Reno. This paper considers a window-based flow control mechanism based on a slightly modified congestion avoidance mechanism of TCP Vegas, and introduces its mathematical model described by a nonlinear difference equation. We calculate its fixed point, and a stability condition of the fixed point is derived.
This paper proposes a unified power flow approach to the modeling of hybrid electric vehicles, resulting in a highly scalable and reconfigurable modeling tool. Furthermore, this simulation tool is used in conjunction ...
详细信息
This paper proposes a unified power flow approach to the modeling of hybrid electric vehicles, resulting in a highly scalable and reconfigurable modeling tool. Furthermore, this simulation tool is used in conjunction with a fuzzy logic, ruled-based controller to optimize the energy efficiency through the control of the power flows of a parallel HEV configuration. Finally, this modeling and control approach is applied to the design and optimization of a hybrid electric sport-utility vehicle. The results show that this modeling approach provides the required modeling flexibility, and that the model and the control strategy based on this power flow approach can be optimized to yield significant fuel economy gains.
We analyze the problem of real-time thickness estimation for patterned wafers during an etching process using in situ spectroscopic ellipsometry. For that, a two-stage estimation algorithm is proposed. The first stage...
详细信息
We analyze the problem of real-time thickness estimation for patterned wafers during an etching process using in situ spectroscopic ellipsometry. For that, a two-stage estimation algorithm is proposed. The first stage is an automatic model calibration algorithm that uses the data collected during an initial interval. The second stage is a nonlinear state estimation systemdesigned for the tuned model. We study the sensitivity of this estimation strategy to variations in the wafer parameters and the process conditions.
Future jet engines will be more complex with more variables to control to meet increasing demands or functionality. The interaction between the engine and aircraft systems will also increase, with mission-specific con...
详细信息
Future jet engines will be more complex with more variables to control to meet increasing demands or functionality. The interaction between the engine and aircraft systems will also increase, with mission-specific control and with control of thrust direction. To utilize the potential of these engines, it is also necessary to use more advanced control concepts than are conventionally used today. Multivariable controllers are most often at the core of these advanced control concepts. Important parts of multivariable controldesign are to select suitable inputs and outputs and how to configure the control laws. This is referred to as control Structure design (CSD). Some methods to accomplish this have been evaluated at Volvo Aero. A model of a typical jet engine has been used as application in this evaluation. The general impression from this work is that the tested methods are very usable to select between a large number of possible structures. However, it is essential to combine the use of the methods with application knowledge and understanding of the control objectives.
Vibration control has been identified by wood products industry as one of the key technologies for increasing wood recovery in wood machining. This paper presents results of a research project for active vibration con...
详细信息
Vibration control has been identified by wood products industry as one of the key technologies for increasing wood recovery in wood machining. This paper presents results of a research project for active vibration control of circular saws using magnetic actuators. An active controlsystem is developed to increase wood recovery by reducing saw blade vibration. For on-line estimation and control of vibration characteristics, a state-space model is developed based on the finite element model analysis and experimental measurement. The characteristics of different vibration modes is estimated on-line by a Kalman filter based state estimator. A state feedback controller design is then implemented on-line and good damping results have been achieved.
暂无评论