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| 2. |
- Olsson, Tomas, et al.
(författare)
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Force/Vision Based Active Damping Control of Contact Transition in Dynamic Environments
- 2007
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Ingår i: Dynamical Vision. - 9783540709312 ; 4358, s. 299-313
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- When a manipulator interacts with objects with poorly damped oscillatory modes, undesired oscillations and bouncing may result. In this paper, we present a method for observer-based control of a rigid manipulator interacting with an environment with linear dynamics.The controller injects a desired damping into the environment dynamics, using both visual-and force sensing for stable control of the contact transition.Stability of the system is shown using an observer-based backstepping design method, and simulations are performed in order to validate the chosen approach.
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| 3. |
- Tunestål, Per, et al.
(författare)
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Closed-Loop Combustion Control of HCCI Engines
- 2003
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Ingår i: Nonlinear and Hybrid Systems in Automotive Control. ; , s. 321-334
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The HCCI engine, with its excellent potential for high efficiency and low NOx emissions, is investigated from a control perspective. Combustion timing, i.e., where in the thermodynamic cycle combustion takes place, is identified as the most challenging problem with HCCI engine control. A number of different means for controlling combustion timing are suggested, and results using a dual-fuel solution are presented. This solution uses two fuels with different ignition characteristics to control the time of autoignition. Cylinder pressure measurement is suggested for feedback of combustion timing. A simple net-heat release algorithm is applied to the measurements, and the crank angle of 50% burnt is extracted. Open-loop instability is detected in some high-load regions of the operating range. This phenomenon is explained by positive feedback between the cylinder wall heating and ignition timing processes. Closed-loop performance is hampered by time delays and model uncertainties. This problem is particularly pronounced at operating points that are open-loop unstable.
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