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An idle speed engine model has been proposed and applied for the development of an idle speed controller for a 125 cc two wheeler spark ignition engine. The procedure uses the measured Indicated Mean Effective Pressure (IMEP) at different speeds at a constant fuel rate and throttle position obtained by varying the spark timing. At idling conditions, IMEP corresponds to the friction mean effective pressure. A retardation test was conducted to determine the moment of inertia of the engine. Using these data, a model for simulating the idle speed fluctuations, when there are unknown torque disturbances, was developed. This model was successfully applied to the development of a closed loop idle speed controller based on spark timing. The controller was then implemented on a dSPACE Micro Autobox on the actual engine. The Proportional Derivative Integral (PID) controller parameters obtained from the model were found to match fairly well with the experimental values, indicating the usefulness of the developed idle speed model. Finally, the optimized idle speed control algorithm was embedded in and successfully demonstrated with an in-house built, low cost engine management system (EMS) specifically designed for two-wheeler applications. � 2011 The Korean Society of Automotive Engineers and Springer-Verlag Berlin Heidelberg.

Reliable decentralised proportional-integral-derivative controller synthesis methods are presented for closed-loop stabilisation of linear time-invariant plants with two multi-input, multi-output (MIMO) channels subject to time delays. The finite-dimensional part of plants in the classes considered here are either stable or they have at most two poles in the unstable region. Closed-loop stability is maintained with only one of the two controllers when the other controller is turned off and taken out of service.

In this paper, a novel two-input two-output current-mode (CM) circuit for providing proportional-integral-derivative (PID) controller and instrumentation amplifier (IA) responses, depending on the passive component selection, is presented. The developed circuit uses only grounded capacitors (PID controller selection) and only grounded resistors (IA choice); accordingly, it is convenient for integrated circuit (IC) fabrication. The proposed new configuration can simultaneously realize both gain variable non-inverting and inverting responses without requiring extra additional components. The proposed topology for providing high output impedance currents can be easily cascaded with other CM structures. Finally, some time domain and frequency domain analysis with SPICE simulation program and experimental results are included to show workability and effectiveness of the proposed circuit. Crown Copyright © 2010.

This work presents a novel predictive model-based proportional integral derivative (PID) tuning and control approach for unknown nonlinear systems. For this purpose, an NARX model of the plant to be controlled is obtained and then it used for both PID tuning and correction of the control action. In this study, for comparison, neural networks (NNs) and support vector machines (SVMs) have been used for modeling. The proposed structure has been tested on two highly nonlinear systems via simulations by comparing control and convergence performances of SVM-and NN-Based PID controllers. The simulation results have shown that when used in the proposed scheme, both NN and SVM approaches provide rapid parameter convergence and considerably high control performance by yielding very small transient-and steady-state tracking errors. Moreover, they can maintain their control performances under noisy conditions, while convergence properties are deteriorated to some extent due to the measurement noises. Copyright © 2009 John Wiley & Sons, Ltd.

The problem of trajectory tracking control of an underactuated autonomous underwater robot (AUR) in a three-dimensional (3-D) space is investigated in this paper. The control of an underactuated robot is different from fully actuated robots in many aspects. In particular, these robot systems do not satisfy Brockett's necessary condition for feedback stabilization and no continuous time-invariant state feedback control law exists that makes a specified equilibrium of the closed-loop system asymptotically stable. The uncertainty of hydrodynamic parameters, along with the coupled, nonlinear dynamics of the underwater robot, also makes the navigation and tracking control a difficult task. The proposed hybrid control law is developed by combining sliding mode control (SMC) and classical proportional-integral-derivative (PID) control methods to reduce the tracking errors arising out of disturbances, as well as variations in vehicle parameters like buoyancy. Here, a trajectory planner computes the body-fixed linear and angular velocities, as well as vehicle orientations corresponding to a given 3-D inertial trajectory, which yields a feasible 6-d.o.f. trajectory. This trajectory is used to compute the control signals for the three available controllable inputs by the hybrid controller. A supervisory controller is used to switch between the SMC and PID control as per a predefined switching law. The switching function parameters are optimized using Taguchi design techniques. The effectiveness and performance of the proposed controller is investigated by comparing numerically with classical SMC and traditional linear control systems in the presence of disturbances. Numerical simulations using the full set of nonlinear equations of motion show that the controller does quite well in dealing with the plant nonlinearity and parameter uncertainties for trajectory tracking. The proposed controller response shows less tracking error without the usually present control chattering. Some practical features of this control law are also discussed. � 2010 Koninklijke Brill NV, Leiden and The Robotics Society of Japan.

Using the direct synthesis method, a PID controller in series with a lead/lag compensator is designed for control of open loop integrating processes with time delay. Set-point weighting is considered for reducing the undesirable overshoot. Guidelines are provided for selection of the desired closed loop tuning parameter in the direct synthesis method and set point weighting parameter. The method gives significant load disturbance rejection performances. Illustrative examples are considered to show the performances of the proposed method. Significant improvement is obtained when compared to recently reported methods. � 2008 The Franklin Institute.

A strong increase in gas inflow due to gas coning and the resulting bean-back because of Gas to Oil Ratio (GOR) constraints can severely limit oil production and reservoir drive energy. In this paper we will use a coupled reservoir-well model to demonstrate that oil production can be increased by using controlled inflow from a gas cone as a natural lift. This model was developed in the knowledge centre Integrated System Approach Petroleum Production (ISAPP) of TNO, TU Delft and Shell, and is based on a commercially available dynamic multiphase well simulation tool (OLGA) and a dynamic multi-phase reservoir simulator (MoReS). In order to give a proof of principle we have implemented a PID feedback controller, which controls the gas fraction in a well by changing its wellhead choke or inflow control valve (ICV) settings, on a realistic test case. We introduce a strategy to find an optimal production set point for this controller and the benefits of using downhole ICVs in comparison to the wellhead choke are investigated. Simulation experiments show that a PID controller is an effective means to prevent a full gas breakthrough and, moreover, can be used to increase the produced oil rate by tuning ICV settings to achieve an optimal well gas fraction. Results show that the coupled simulations could be significantly more accurate in comparison to stand-alone well or reservoir simulations. In current operations ICVs are mostly used to completely shut down well segments that experience gas coning. We show that by keeping these ICVs open in a controlled way the - otherwise undesirable - phenomenon of gas coning can be used to increase oil production.

A strong increase in gas inflow due to gas coning and the resulting bean-back because of Gas to Oil Ratio (GOR) constraints can severely limit oil production and reservoir drive energy. In this paper we will use a coupled reservoir-well model to demonstrate that oil production can be increased by using controlled inflow from a gas cone as a natural lift. This model was developed in the knowledge centre Integrated System Approach Petroleum Production (ISAPP) of TNO, TU Delft and Shell, and is based on a commercially available dynamic multiphase well simulation tool (OLGA) and a dynamic multi-phase reservoir simulator (MoReS). In order to give a proof of principle we have implemented a PID feedback controller, which controls the gas fraction in a well by changing its wellhead choke or inflow control valve (ICV) settings, on a realistic test case. We introduce a strategy to find an optimal production set point for this controller and the benefits of using downhole ICVs in comparison to the wellhead choke are investigated. Simulation experiments show that a PID controller is an effective means to prevent a full gas breakthrough and, moreover, can be used to increase the produced oil rate by tuning ICV settings to achieve an optimal well gas fraction. Results show that the coupled simulations could be significantly more accurate in comparison to stand-alone well or reservoir simulations. In current operations ICVs are mostly used to completely shut down well segments that experience gas coning. We show that by keeping these ICVs open in a controlled way the - otherwise undesirable - phenomenon of gas coning can be used to increase oil production. Copyright 2008, Society of Petroleum Engineers.

Date of Conference: 27-29 June 2007 Conference name: 2007 Mediterranean Conference on Control & Automation In this paper we give an algorithm that determines the set of all stabilizing proportional-integral-derivative (PID) controllers that places the poles of the closed loop system in a desired stability region S. The algorithm is applicable to linear, time invariant, single-input single-output plants. The solution is based on a generalization of the Hermite-Biehler theorem applicable to polynomials with complex coefficients and the the application of a stabilizing gain algorithm to three auxiliary plants. ©2007 IEEE.

In this paper we present a new queue length based Internet congestion control protocol which is shown through simulations to work effectively. The control objective is to regulate the queue size at each link so that it tracks a reference queue size chosen by the designer. To achieve the latter, the protocol implements at each link a certainty equivalent proportional controller which utilizes estimates of the effective number of users utilizing the link. These estimates are generated online using a novel estimation algorithm which is based on online parameter identification techniques. The protocol utilizes an explicit multi-bit feedback scheme and does not require maintenance of per flow states within the network. Extensive simulations indicate that the protocol is able to guide the network to a stable equilibrium which is characterized by max-min fairness, high utilization, queue sizes close to the reference value and no observable packet drops. In addition, it is found to be scalable with respect to changing bandwidths, delays and number of users utilizing the network. The protocol also exhibits nice transient properties such as smooth responses with no oscillations and fast convergence. © 2007 IEEE. 584 589 Sponsors: IEEE Systems, Man and Cybernetics Society Conference code: 70274 Cited By :4

Conference name: 6th IFAC Workshop on Time Delay Systems, 2006 Date of Conference: 10-12 July, 2006 Conditions are presented for closed-loop stabilizability of linear time-invariant (LTI) multi-input, multi-output (MIMO) plants with I/O delays (time delays in the input and/or output channels) using PID (Proportional + Integral + Derivative) controllers. We show that systems with at most two unstable poles can be stabilized by PID controllers provided a small gain condition is satisfied. For systems with only one unstable pole, this condition is equivalent to having sufficiently small delay-unstable pole product. Our method of synthesis of such controllers identify some free parameters that can be used to satisfy further design criteria than stability. Copyright © 2006 IFAC.

The classical multivariable Smith predictor is extended to multivariable nonsquare systems with multiple time delays where the number of process inputs is higher than the process outputs. Pairing for input and output variables is carried out using the block relative gain technique. Simplified decoupling method is applied to design the decouplers. The decoupled processes are modeled as first-order plus time-delay model or second-order plus time-delay model with positive/negative zero. The controllers are designed individually based on the identified models. For the delay-compensated system, decentralized multivariable proportional-integral controllers are designed by internal model control method for FOPTD models. To show the improvement, PI controllers for the uncompensated system are also designed by simplified internal model control method. For SOPTD models, a method similar to Chien et al. [Simple PID controller tuning method for processes with inverse response plus dead time or large overshoot response plus dead time, Ind. Eng. Chem. Res., 42, 4461-4477 (2003)] is proposed for controller design in the delay compensator. The proposed method is applied to shell standard control problem (3 input and 2 output), hot oil fractionator (4 input and 2 output) and mixing tank (3 input and 2 output). Simulation studies were carried out for both servo and regulatory problems. Robustness studies were carried out for uncertainty in all the process model parameters. It is shown that the performance of the multivariable delay-compensated system with decentralized PI controllers is significantly better than that of the multivariable control system without any delay compensator. � Indian Institute of Science.

The control of large segmented telescopes is a challenging one due to the complexity and high order of the system. The high order dynamics lead to high order controllers that require more memory and faster computations for implementation. While this may not pose a serious problem for a small number of segments, as the number of segments increases the computational requirements are becoming enormous. A test-bed that simulates in real-time a large segmented telescope is used to test the performance and computational requirements of several control designs. Three decentralized control designs were selected for implementation. These include a decentralized state feedback proportional plus integral (DSFPI) controller, a decentralized output feedback proportional plus integral (DOPFI) controller, and a decentralized direct adaptive output feedback (DDAOF) controller. The DSFPI controller requires more memory space and computational power than the DOFPI and DDAOF controllers. The DOFPI requires less memory space and computational operations but it performs worst than the other two controllers. The DDAOF requires an acceptable amount of memory space and computational operations and has better performance than the other two controllers. 1 762 767 Sponsors: Honeywell laboratories XEROX National Instruments the Mathworks Conference code: 62450 Cited By :3

Experimental identification of a delay plus first-order transfer function model for a liquid level system is carried out by using the closed-loop method proposed by Yuwana and Seborg (AIChE J., 28 (1982) 434-440), Jutan and Rodrigues (Can. J. Chem. Eng., 62 (1984) 802-807), Lee (AIChE J., 35 (1989) 329-331) and Chen (AIChE J., 35 (1989) 2037-2039). Based on the identified model, conventional proportional-integral (PI) controllers are designed and implemented experimentally to compare the closed-loop responses.

The design of a model reference parallel cascade nonlinear controller is analyzed for an unstable continuous stirred tank bioreactor (CSTBR) which is represented by a nonlinear system x = f(x) + g(x,d) u, y = cx. Integral and derivative control actions are incorporated into the control law. A theoretical analysis of the robustness of the proposed control scheme under process model parameter uncertainty is provided. The method is applied theoretically to the substrate concentration control of a CSTBR which has severe nonlinearity and steady-state multiplicity.

The method proposed by Rojas et al.1 for the design of sliding mode controllers (SMC) for unstable first order plus time delay systems, is extended for delay-time constant ratio (?) up to 1.8. The SMC settings obtained for various ? are fitted by simple equations. Up to ? = 1.2, the method is found to be more robust than that of latest PID Controller proposed by Padmasree et al. 2 There is no method available in literature to stabilize unstable systems using PID controller for ? > 1.2. Simulation results are also given for a nonlinear bioreactor control problem.

The present paper describes the design of a hybrid actuation control concept, a fuzzy logic proportional-integral-derivative plus a conventional on-off controller, for a new morphing mechanism using smart materials as actuators, which were made from shape memory alloys (SMA). The research work described here was developed for the open loop phase of a morphing wing system, whose primary goal was to reduce the wing drag by delaying the transition (from laminar to fully turbulent flows) position toward the wing trailing edge. The designed controller drives the actuation system equipped with SMA actuators to modify the flexible upper wing skin surface. The designed controller was also included, as an internal loop, in the closed loop architecture of the morphing wing system, based on the pressure information received from the flexible skin mounted pressure sensors and on the estimation of the transition location.The controller’s purposes were established following a comprehensive presentation of the morphing wing system architecture and requirements. The strong nonlinearities of the SMA actuators’ characteristics and the system requirements led to the choice of a hybrid controller architecture as a combination of a bi-positional on-off controller and a fuzzy logic controller (FLC). In the chosen architecture, the controller would behave as a switch between the SMA cooling and heating phases, situations where the output current is 0A or is controlled by the FLC.In the design phase, a proportional-integral-derivative scheme was chosen for the FLC. The input-output mapping of the fuzzy model was designed, taking account of the system’s error and its change in error, and a final architecture for the hybrid controller was obtained. The shapes chosen for the inputs’ membership functions were s -function, π-function, and z -function, and product fuzzy inference and the center average defuzzifier were applied (Sugeno).