https://www.fossen.biz/home/papers/JohansenFossen%20Automatica%202013.pdf

Control allocation—A survey

Multivariable adaptive control

This paper is concerned with the fault detection (FD) problem in finite frequency domain for continuous-time Takagi-Sugeno fuzzy systems with sensor faults. Some finite-frequency performance indices are initially introduced to measure the fault/reference input sensitivity and disturbance robustness. Based on these performance indices, an effective FD scheme is then presented such that the generated residual is designed to be sensitive to both fault and reference input for faulty cases, while robust against the reference input for fault-free case. As the additional reference input sensitivity for faulty cases is considered, it is shown that the proposed method improves the existing FD techniques and achieves a better FD performance. The theory is supported by simulation results related to the detection of sensor faults in a tunnel-diode circuit.

Fault detection in finite frequency domain for Takagi-Sugeno fuzzy systems with sensor faults.

This paper presents a recent study to investigate flight dynamics and adaptive control methods for stability and control recovery of a damaged generic transport aircraft. Aerodynamic modeling of damage effects is performed using an aerodynamic code to assess changes in the stability and control derivatives of the damaged aircraft. Flight dynamics for a general aircraft are developed to account for changes in aerodynamics, mass properties, and the center of gravity that can compromise the stability of the damaged aircraft An iterative trim analysis is developed to compute incremental trim states. A neural network hybrid direct-indirect adaptive flight control is developed for the stability augmentation control of the damaged aircraft. The proposed method performs an online estimation of damaged plant dynamics to improve the command tracking performance in conjunction with a direct adaptive controller. The plant estimation is based on two approaches: 1) an indirect adaptive law derived from the Lyapunov stability theory to ensure that the tracking error is bounded, and 2) a recursive least-squares method that minimizes the modeling error. Simulations show that the hybrid adaptive controller can provide a significant improvement in the tracking performance over a direct adaptive controller working alone.

Flight Dynamics and Hybrid Adaptive Control of Damaged Aircraft

An adaptive disturbance rejection algorithm is developed for the standard control problem The multiple input-multiple output (MIMO) system and controller are represented as ARMARKOV/Toeplitz models, and the parameter matrix of the compensator is updated online by means of a gradient algorithm The algorithm requires minimal knowledge of the plant, specifically, the numerator of the ARMARKOV model of the transfer function from the control inputs to the performance variables is required No knowledge about the spectrum of the disturbance is needed Experimental results demonstrating tonal and broadband disturbance rejection in an acoustic duct are presented

Adaptive disturbance rejection using ARMARKOV/Toeplitz models

Aircraft damage causes large uncertain system parametric and structural changes which lead to unknown deviations of the aircraft equilibrium points and unknown coupling of the aircraft dynamics. To deal with such unknown changes, we use a sequential linear model with a dynamics offset to represent a linearized aircraft system before and after damage. A state feedback multivariable model reference adaptive control (MRAC) scheme is developed for such a linear model, with adaptive compensation of the uncertain dynamics offset as well as system parametric uncertainties. Desired closed-loop signal boundedness and asymptotic output tracking are established. Numerical values of linearized models from the NASA GTM were used in the simulation study and its results verified the desired system performance despite uncertain damage.

A multivariable MRAC design using state feedback for linearized aircraft models with damage

This paper presents an adaptive scheme to adjust the gains of multiple actuating signals, as combined with an adaptive state feedback control law, for linear time-invariant single-output systems. Adaptation of multiple actuating signals makes it possible to relax some critical design conditions for desired system performance. A controller parametrization and a plant-model matching structure are derived. As an illustrative example, a simulation study is carried out for adaptive cooperative control of aircraft ailerons and rudder for desired lateral motion of tracking a reference trajectory.

A study of adaptation of multiple actuating signals for LTI systems

This paper studies the multivariable model reference adaptive control (MRAC) design for aircraft systems under simultaneous actuator failures and airframe damage. A modeling study of the aircraft under failure and damage conditions is conducted, which captures the key characteristics of the aircraft dynamics under such hazardous conditions. The key design conditions for the multivariable MRAC design are studied for nominal and post-hazard aircraft systems, and the invariance of these essential conditions is concluded under realistic failure and damage conditions. A multivariable MRAC scheme is developed to ensure stability and asymptotic output tracking for the aircraft in the presence of uncertain actuator failures and airframe damage. Simulation results are presented to demonstrate the application of the proposed adaptive control scheme to the NASA Generic Transport Model (GTM).

/pdf/a-multivariable-mrac-design-for-aircraft-systems-under-4486bjd8h8.pdf

A multivariable MRAC design for aircraft systems under failure and damage conditions

A vapor compression heat pump (VCHP) system for an electrified vehicle and a method for de-icing the VCHP system is provided. The electrified vehicle may include a vehicle cabin, the VCHP system, and a controller. The VCHP system may be in thermal communication with the cabin and include an outside heat exchanger and a compressor. The controller may be configured to, in response to detection of a predefined ice condition associated with the outside heat exchanger, output commands to adjust a speed of the compressor to influence a temperature of refrigerant flowing through the compressor such that the refrigerant carries an amount of heat sufficient to eliminate the predefined ice condition within a preselected time period. The predefined ice condition may be a condition in which the heat exchanger has accumulated ice or is likely to accumulate ice.

De-Icing Control in a Vapor Compression Heat Pump System

A hybrid electric power-split vehicle, equipped with a continuously variable transmission coupling an electric motor/generator (EM) with a combustion engine (CE), includes systems and methods that reduce possible resonant noise and vibration during CE startup, by improved EM control, to generate compensating EM torque to counter act such possible resonant noise and vibration. The systems and methods include predetermined baseline CE operating condition (OC) cranking torque profiles stored as OC grids (SOCGs). A start profile is generated from selected cranking torque SOCGs, and also from selected historical start OCGs (HOCGs) of prior engine and/or CE starts, which include prior start noise and vibration metrics along with prior start OCs and related parameters. The start profile is calibrated using a blend factor that is generated from comparisons of SOCGs, and utilized to generate a feed-forward torque signal that adjusts EM torque to reduce the startup noise and vibration resonances.

Yu Liu

Papers

A multivariable MRAC design using state feedback for linearized aircraft models with damage

A study of adaptation of multiple actuating signals for LTI systems

A multivariable MRAC design for aircraft systems under failure and damage conditions

De-Icing Control in a Vapor Compression Heat Pump System

HEV engine start vibration reduction system