Fault tolerant control of feedback linearizable systems with stuck actuators

Abstract

An ordinary Petri-net (PN) based approach is proposed to design the programmable logical controller (PLC) for preventing collisions between vehicles in an automated guided vehicles (AGV) system. First, method is proposed to model an AGV system as an ordinary PN, called the plant PN. Second, for collision prevention in an AGV system, module control methods are proposed to design the PN supervisor (the closed-loop PN) by augmenting the plant PN. In detail, three modules are defined the line, divide, and merge modules, in the plant PN, and the control module methods are presented for each of these three modules. As a result, the closed-loop PN of an AGV system is obtained and can be analyzed using the PN theory. Finally, method is proposed to translate a closed-loop PN into a ladder diagram. Consequently, the PN supervisor is implemented by a PLC using these proposed methods. A laboratory AGV system is used to illustrate this approach.

Prescribed-performance fault-tolerant control for feedback linearisable systems with an aircraft application

“…Different from Tang et al (1990), Liang et al (2004) and Tao et al (2010), addressing the fault patterns of loss of effectiveness and extra disturbance, and by exploiting the residual control authority, the actuator redundancy is avoided in this paper in order to exclude the technical difficulties and high prices (Fiorentini and Serrani 2012). Compared with the closed-loop stability analysis in Ma and Tao (2000) and the degraded performances in Dardinier-Maron et al (1999) and Wang and Zhou (2008), the more demanding tracking error performance, i.e., the prescribed transient and steady-state behaviors, are desirable to be maintained during the actuator failures.…”

“…It is obvious that, besides stuck or completed loss of an actuator (Dardinier-Maron et al 1999;Tang et al 1990; Wang and Zhou 2008;Tao et al 2010), there are some other important patterns of actuator failures, such as loss of effectiveness and input disturbance (Fan and Song 2012). For example, as a result of the hydraulic or pneumatic leakage, increased resistance or fall in the supply voltage and so on, partially failed actuator produces only a part of the normal actuation, thus the actuator is affected by loss of effectiveness, where a minimum control authority is left during the actuator fault (Boskovic and Mehra 2010;Li et al 2010;Fan and Song 2012).…”

“…More specifically, in the presence of actuator uncertainties, to improve the reliability of the feedback linearization technique and the system performance, the study of FTC for FLS is of theoretical and practical value, which is the main purpose of this paper. Considering stuck or complete loss of the actuators, this issue has been investigated with (Tang et al 1990;Tao et al 2010) or without actuator redundancy (Dardinier-Maron et al 1999;Wang and Zhou 2008). Despite the actuator failures, employing adaptive compensation schemes, the researches Tang et al (1990) and Tao, Chen, Tang, and Joshi (2010) ensure asymptotic output tracking and boundedness of the closed-loop signals.…”

“…Despite the actuator failures, employing adaptive compensation schemes, the researches Tang et al (1990) and Tao, Chen, Tang, and Joshi (2010) ensure asymptotic output tracking and boundedness of the closed-loop signals. Without actuator redundancy, the optimization technique exploited in Dardinier-Maron et al (1999) results in a large loss of the nominal performance, while the study Wang and Zhou (2008) ensures only boundedness of the closed-loop signals and satisfactory performance for the output with reduced dimension. Parallel to these developments, when the actuators are affected by nonsmooth nonlinearities or input disturbances, the control of FLS has been studied in Ma and Tao (2000) and Liang et al (2004).…”

“…For example, the research Ma and Tao (2000) is limited to stability analysis for the FLS under actuator failures, where no further system performance such as output tracking is involved. Without actuator redundancy, the fault patterns in Dardinier-Maron et al (1999), Wang and Zhou (2008) are restricted to stuck or complete loss of the actuators, where the nominal performance is significantly degraded during the actuator faults. Although actuator redundancy has been proved as an effective strategy to achieve increased fault tolerance (Tang et al 1990;Liang et al 2004;Tao et al 2010), owing to the technical difficulties and high prices, duplicating actuators in the system is often not a good option (Fiorentini and Serrani 2012).…”