Variable Interval Sampling Based Time Varying Tracking Control With Application to Camless Engine

2014 ◽  
Author(s):  
Meng Yang ◽  
Zongxuan Sun
Keyword(s):  
Tracking Control ◽  
Variable Interval ◽  
Sampling Interval ◽  
Tracking Performance ◽  
Time Varying ◽  
Rotational Angle ◽  
Actuation System ◽  
Sampling Points ◽  
Camless Engine ◽  
Interval Sampling

This paper investigates the variable interval sampling based time-varying tracking control in the rotational angle domain. It is found that more sampling points per revolution provide better tracking performance but increase the computational burden. To solve the problem, a varying interval sampling approach is presented to optimize the angular sampling interval for the reference profile, while maintaining the same total number of sampling points. The tracking performance is improved by considering the tracking errors between the sampling points in selecting the optimal sampling intervals. Experimental results from a time-varying internal model based camless engine valve actuation system demonstrate the effectiveness of the proposed method. A quantitative analysis helps to highlight the strength of the variable interval sampling on less computational complexity and better tracking performance.

scholarly journals Design and Experimental Investigation of Rotational Angle-Based Tracking Control

2016 ◽  
Vol 138 (7) ◽  
Author(s):  
Meng Yang ◽  
Xingyong Song ◽  
Zongxuan Sun
Keyword(s):  
Tracking Control ◽  
Internal Model ◽  
Angular Displacement ◽  
Tracking Error ◽  
Sampling Interval ◽  
Linear Matrix ◽  
Computationally Efficient ◽  
Rotational Angle ◽  
Internal Model Principle ◽  
Actuation System

This paper investigates tracking control in the rotational angle domain based on the time-varying internal model principle. The objective is to enable precise, reliable, and computationally efficient output tracking of signals that are dependent on angular displacement. To achieve desired performance, existing approaches based on internal model principle require a large number of samples per revolution, which significantly increases the controller order and also poses challenges for the transient performance. To address those issues, a varying sampling interval approach is proposed, where the angular sampling locations are not fixed but optimized based on tracking errors between sampling points so that desired performance can be achieved without increasing the number of samples. Meanwhile, to improve the convergence rate of the tracking error, additional linear matrix inequalities (LMI) constraints are added to the existing stabilizer synthesis. Through experimental study on a camless engine valve actuation system, the effectiveness of the proposed approaches is demonstrated. It is shown that, compared with the fixed interval sampling, the varying sampling approach can reduce the tracking error by over 50%.

Transient Control of a Camless Valve Actuation System Using a Time-Varying Repetitive Controller

2010 ◽  
Author(s):  
Pradeep Gillella ◽  
Zongxuan Sun
Keyword(s):  
Engine Speed ◽  
Combustion Engine ◽  
Sampling Rate ◽  
Control Design ◽  
Time Varying ◽  
Rotational Angle ◽  
Actuation System ◽  
Valve Motion ◽  
Actuation Systems ◽  
Valve Actuation

Camless valve actuation systems, also referred to as Fully Flexible Valve Actuation systems, use electronically controlled actuators to replace the camshaft in an internal combustion engine. This paper presents the control design for such an actuation system to enable the precise valve motion control during engine speed transients. The desired valve motion (reference) remains periodic in the crank angle domain, but becomes cyclic and aperiodic in the time domain when the engine speed changes in real-time. This phenomenon motivates the control design in the rotational angle domain. However, this approach results in a time-varying model for the plant. A systematic method for obtaining the discrete time-varying Input/Output representation of higher order systems is developed to enable the application of the newly developed time-varying repetitive control to plants with complex dynamics. The use of a variable sampling rate helps accurately represent complex reference signals using low dimensional models. The implementation of the simulations on a rapid control prototyping system helps identify and address potential issues that influence the controller execution time which directly affects the maximum engine speed at which it can be used.

scholarly journals Formation Tracking Control and Obstacle Avoidance of Unicycle-Type Robots Guaranteeing Continuous Velocities

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4374
Author(s):  
Jose Bernardo Martinez ◽  
Hector M. Becerra ◽  
David Gomez-Gutierrez
Keyword(s):  
Obstacle Avoidance ◽  
Tracking Control ◽  
Global Coordinate System ◽  
Avoidance Task ◽  
Time Varying ◽  
Control Laws ◽  
Formation Tracking ◽  
Control Scheme ◽  
First Time ◽  
Hierarchical Scheme

In this paper, we addressed the problem of controlling the position of a group of unicycle-type robots to follow in formation a time-varying reference avoiding obstacles when needed. We propose a kinematic control scheme that, unlike existing methods, is able to simultaneously solve the both tasks involved in the problem, effectively combining control laws devoted to achieve formation tracking and obstacle avoidance. The main contributions of the paper are twofold: first, the advantages of the proposed approach are not all integrated in existing schemes, ours is fully distributed since the formulation is based on consensus including the leader as part of the formation, scalable for a large number of robots, generic to define a desired formation, and it does not require a global coordinate system or a map of the environment. Second, to the authors’ knowledge, it is the first time that a distributed formation tracking control is combined with obstacle avoidance to solve both tasks simultaneously using a hierarchical scheme, thus guaranteeing continuous robots velocities in spite of activation/deactivation of the obstacle avoidance task, and stability is proven even in the transition of tasks. The effectiveness of the approach is shown through simulations and experiments with real robots.

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