An Active Suspension Strategy Using State Reconstruction

1990 ◽  
Author(s):  
P. K. Warner ◽  
M. J. Vanderploeg ◽  
J. E. Shannan
Keyword(s):  
Kalman Filter ◽  
State Feedback ◽  
Active Suspension ◽  
Response Surfaces ◽  
State Variables ◽  
Ground Vehicles ◽  
Suspension Systems ◽  
Full State ◽  
Full State Feedback ◽  
The Ideal

Abstract Many studies have shown that active suspensions using full state feedback can significantly improve the ride performance of ground vehicles. Using a seven degree of freedom vehicle model and a Kalman filter, this paper investigates the effects of reduced state feedback on active and semi-active suspension systems. Particular attention is given to control of pitch motion, which is usually considered to be the most uncomfortable of rigid body motions. The effects of phase differences between the tires is presented using frequency response surfaces. The Kalman filter, which reconstructs the state variables from a reduced set of observed variables, yields improvements in ride which compare well with the ideal active suspension without the need to measure all states. The Kalman filter system with active dampers instead of ideal actuators also yields ride improvements approaching the ideal systems.

Active Vehicle Suspension Control Using Full State-Feedback Controller

2015 ◽  
Vol 1115 ◽  
pp. 440-445 ◽  
Author(s):  
Musa Mohammed Bello ◽  
Amir Akramin Shafie ◽  
Raisuddin Khan
Keyword(s):  
State Feedback ◽  
Ride Comfort ◽  
Active Suspension ◽  
Suspension System ◽  
Feedback Controller ◽  
Vehicle Suspension ◽  
Passive Suspension ◽  
Full State ◽  
Full State Feedback ◽  
Passive Suspension System

The main purpose of vehicle suspension system is to isolate the vehicle main body from any road geometrical irregularity in order to improve the passengers ride comfort and to maintain good handling stability. The present work aim at designing a control system for an active suspension system to be applied in today’s automotive industries. The design implementation involves construction of a state space model for quarter car with two degree of freedom and a development of full state-feedback controller. The performance of the active suspension system was assessed by comparing it response with that of the passive suspension system. Simulation using Matlab/Simulink environment shows that, even at resonant frequency the active suspension system produces a good dynamic response and a better ride comfort when compared to the passive suspension system.

Reduced Order Design of Active Suspension Control

1990 ◽  
Vol 112 (4) ◽  
pp. 604-610 ◽  
Author(s):  
M. A. Salman ◽  
A. Y. Lee ◽  
N. M. Boustany
Keyword(s):  
Control Strategies ◽  
Local Level ◽  
Hierarchical Control ◽  
Active Suspension ◽  
Reduced Order ◽  
Suspension Systems ◽  
Suspension Control ◽  
Full State ◽  
Full State Feedback ◽  
Fast Control

The presence of fast and slow modes in suspension systems is utilized in the design of two reduced-order active suspension control strategies. The first strategy is obtained by combining the solutions of slow and fast control sub-problems. The second strategy is based on a two-level hierarchical control design. The local level requires measurements of local fast variables, namely the unsprung mass velocities. The coordinating level relies on measurements of slow variables, namely, suspension deflections, sprung mass velocity, and mass pitch rate. Neither strategy requires tire deflection measurements. In spite of their simplified structure, simulation results indicate that their performance is comparable to that of the full-state feedback design.

Theoretical Analysis of Active Suspension Performance Using a Four-Wheel Vehicle Model

1989 ◽  
Vol 203 (2) ◽  
pp. 125-135 ◽  
Author(s):  
M B A Abdel Hady ◽  
D A Crolla
Keyword(s):  
Measurement Errors ◽  
State Feedback ◽  
Load Transfer ◽  
Feedback System ◽  
Active Suspension ◽  
Lateral Acceleration ◽  
Practical Implementation ◽  
Control Laws ◽  
Full State ◽  
Full State Feedback

Techniques for obtaining control laws for an active suspension implemented at all four wheel stations of a vehicle are outlined. It is shown that the classical optimal control law based on full state feedback can be replaced by one that involves limited state feedback—omitting, in particular, the ground input information—and that may involve measurement errors. Performance of this system is almost as good as that of the full state feedback system and is much more attractive in terms of its practical implementation. Previous work, much of which has been based on the quarter car model, is extended so that the performance indices may include body roll, body pitch, seat lateral acceleration and lateral and fore/aft dynamic load transfer.

Study of Sliding Mode Control in Self-Balancing Two-Wheeled Inverted Car

2012 ◽  
Vol 241-244 ◽  
pp. 2000-2003 ◽  
Author(s):  
De Yong Gao ◽  
Peng Wu Han ◽  
Dai Sheng Zhang ◽  
Yong Jie Lu
Keyword(s):  
State Feedback ◽  
Sliding Mode ◽  
Balance Control ◽  
State Feedback Control ◽  
The Self ◽  
Sliding Mode Controller ◽  
Modeling Process ◽  
Full State ◽  
Full State Feedback ◽  
The Ideal

Using the method of Newtonian mechanics, the paper analyzes balance control problems of the self-balanced two wheeled cars, describes the detailed modeling process and simplifies it necessarily according to the needs of the control rate. It designs the full state feedback controller (LQR) and sliding-mode controller respectively, carries out the simulation and gets the ideal simulation curve. The comparisons of the simulation results show that the sliding-mode controller can get better performance than the full state feedback control in the control of the self-balanced two wheeled car.

scholarly journals An LQR-Based Controller Design for an LCL-Filtered Grid-Connected Inverter in Discrete-Time State-Space under Distorted Grid Environment

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2062 ◽  
Author(s):  
Thuy Tran ◽  
Seung-Jin Yoon ◽  
Kyeong-Hwa Kim
Keyword(s):  
State Feedback ◽  
System State ◽  
State Variables ◽  
Linear Quadratic ◽  
Control Approach ◽  
Distorted Grid ◽  
Control Scheme ◽  
Full State ◽  
Full State Feedback ◽  
Grid Connected Inverter

In order to alleviate the negative impacts of harmonically distorted grid conditions on inverters, this paper presents a linear quadratic regulator (LQR)-based current control design for an inductive-capacitive-inductive (LCL)-filtered grid-connected inverter. The proposed control scheme is constructed based on the internal model (IM) principle in which a full-state feedback controller is used for the purpose of stabilization and the integral terms as well as resonant terms are augmented into a control structure for the reference tracking and harmonic compensation, respectively. Additionally, the proposed scheme is implemented in the synchronous reference frame (SRF) to take advantage of the simultaneous compensation for both the negative and positive sequence harmonics by one resonant term. Since this leads to the decrease of necessary resonant terms by half, the computation effort of the controller can be reduced. With regard to the full-state feedback control approach for the LCL-filtered grid connected inverter, additional sensing devices are normally required to measure all of the system state variables. However, this causes a complexity in hardware and high implementation cost for measurement devices. To overcome this challenge, this paper presents a discrete-time current full-state observer that uses only the information from the control input, grid-side current sensor, and grid voltage sensor to estimate all of the system state variables with a high precision. Finally, an optimal linear quadratic control approach is introduced for the purpose of choosing optimal feedback gains, systematically, for both the controller and full-state observer. The simulation and experimental results are presented to prove the effectiveness and validity of the proposed control scheme.

Flexible-Joint Humanoid Balancing Augmentation via Full-State Feedback Variable Impedance Control

2021 ◽  
Vol 13 (2) ◽  
Author(s):  
Emmanouil Spyrakos-Papastavridis ◽  
Jian S. Dai
Keyword(s):  
State Feedback ◽  
Position Control ◽  
Impedance Control ◽  
Humanoid Robots ◽  
Flexible Joint ◽  
Model Free ◽  
Floating Base ◽  
Full State ◽  
Full State Feedback ◽  
Series Elastic Actuators

Abstract This paper attempts to address the quandary of flexible-joint humanoid balancing performance augmentation, via the introduction of the Full-State Feedback Variable Impedance Control (FSFVIC), and Model-Free Compliant Floating-base VIC (MCFVIC) schemes. In comparison to rigid-joint humanoid robots, efficient balancing control of compliant bipeds, powered by Series Elastic Actuators (or harmonic drives), requires the design of more sophisticated controllers encapsulating both the motor and underactuated link dynamics. It has been demonstrated that Variable Impedance Control (VIC) can improve robotic interaction performance, albeit by introducing energy-injecting elements that may jeopardize closed-loop stability. To this end, the novel FSFVIC and MCFVIC schemes are proposed, which amalgamate both collocated and non-collocated feedback gains, with power-shaping signals that are capable of preserving the system's stability/passivity during VIC. The FSFVIC and MCFVIC stably modulate the system's collocated state gains to augment balancing performance, in addition to the non-collocated state gains that dictate the position control accuracy. Utilization of arbitrarily low-impedance gains is permitted by both the FSFVIC and MCFVIC schemes propounded herein. An array of experiments involving the COmpliant huMANoid reveals that significant balancing performance amelioration is achievable through online modulation of the full-state feedback gains (VIC), as compared to utilization of invariant impedance control.

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