IAES Inter national J our nal of Robotics and A utomation (IJRA) V ol. 10, No. 3, September 2021, pp. 261 274 ISSN: 2089-4856, DOI: 10.11591/ijra.v10i3.pp261-274 261 P erf ormance e v aluation of industrial ether net pr otocols f or r eal-time fault detection based adapti v e obser v er in netw ork ed contr ol systems with netw ork communication constraints Samba Aim ´ e Her v ´ e 1 , Y er emou T amtsia A ur elien 2 , Nneme Nneme Leandr e 3 1,2 National Adv anced School of Engineering , Uni v ersity of Douala, Douala, Cameroon 3 Adv anced T eacher is T raining Colle ge for T echnical Education, Uni v ersity of Douala, Douala, Cameroon Article Inf o Article history: Recei v ed Mar 20, 2020 Re vised May 16, 2021 Accepted Jul 23, 2021 K eyw ords: Adapti v e sliding mode observ er F ault detection Industrial ethernet P ack et losses Netw ork ed control systems ABSTRA CT In this paper , the performance e v aluation of industrial ethernet (EtherNet/IP , Ether - CA T and PR OFINET IR T) netw orks has been studi ed for choosing the right protocol in real-time f ault detection based adapti v e sliding mode observ er in netw ork ed control systems (NCSs) under time netw ork-induced delays, stochastic pack et losses, access constraints and bounded disturbances. An adapti v e sliding-mode observ er based f ault detection is presented. The dynamic h ydroelectric po wer plant model is used to v erify the ef fecti v eness of the proposed method based on T rueT ime and Matlab/ Simulink, corroborated our predictions that an ethernet for control automation technology (Ether - CA T) protocol w ould be more appropriate to reduce the f alse alarm rate and increasing the ef cienc y of the remote control of industrial h ydroelectric po wer plant. This is an open access article under the CC BY -SA license . Corresponding A uthor: Samba Aim ´ e Herv ´ e National Adv anced School of Engineering Uni v ersity of Douala, Douala, Cameroon Email: aimeherv esamba@yahoo.fr 1. INTR ODUCTION The concept of netw ork ed control systems (NCSs) ha v e been mentioned by man y scientists in t heir w orks as early as the end of the twentieth century . Because the lo w maintenance cost and con v enient installa- tion, NCSs ha v e aroused widely concerned. Due to the introduction of shared netw ork, ne w constraints occur when the plant outputs and control inputs are transmitted through communication netw orks: quantization errors in the signals transmitted through the netw ork, pack et dropouts, netw ork-induced delay , access constraints and po wer consumption mainly in wireless netw ork ed control systems [1]-[5], thus increasing the comple xity of the system. These f actors will af fect the reliability of the system, and cause the system performance decline. In order to impro v e the reliability and security of the NCSs, f ault diagnosis has been widely used in engineer - ing systems such as aero engines, dynamic v ehicle systems, chemical processes, and po wer systems [6]-[8]. F ault detection (FD) has recei v ed widespread attention as one of the most considerable parts of f ault diagnosis. F ailure is the phenomenon that the state of the system de viates from the normal w orking range due to satura- tion, stuck or de gradation of actuators, sensors and other components, which has a ne g ati v e inuence on the system performance. As a result, it is v ery signicant to detect the system f aults as s oon as possible to ensure the safety of systems. There are man y researching results on FD for kinds of systems with v arious methods J ournal homepage: http://ijr a.iaescor e .com Evaluation Warning : The document was created with Spire.PDF for Python.
262 ISSN: 2089-4856 [9]-[12]. P an and Y ang [11], H FD lter is proposed for NCS with lar ge transfer del ays. An adapti v e Kalman lter for NCSs is proposed in [12] to minimize the ef fects of delay on the residual signal. The f ault detection system for NCSs with pack et losses w as been designed by modelling the NC Ss as a Mark o v jumping linear system [13], [14]. F or research w ork of FD problem of NCSs, construct appropriat e lters and state observ ers as residual generators to generate residual signals [15]-[17]. The problem of FD of a NCSs under communica- tion constraints limited is considered [18]. The practical guideline for selecting the right protocol in industrial netw ork ed control systems (NCSs) is pro vided in [12], [19]. The e v aluated the performance of MPOLSR pro- tocol and MD AR T protocol using NS-2 based on the success deli v ery rate and pack et loss bas been studied in [20]. Inspired by the abo v e discussions, the main goal of this paper is to de v oted to FD of NCS subject to both random communication delays, stochastic pack et losses, limited communication and access constraints. The main contrib utions of this w ork can be highlighted as follo ws: - The f ault detection problem is e xtended for a class of netw ork ed control systems (NCSs) with random pack et losses, time-v arying delays and limited communication to reect more realistic en vironment, - Adapti v e Sliding mode observ er approach is utilized to deal with the f ault detection, - Residuals generator is designed, reducing the f alse alarm rate. Then, the residual signals are e v aluated and compared with a threshold to detect the f aults occurrences. - Application to a Hydro-turbine go v erning system [21], [22] sho ws that the proposed method achie v es better f ault detection. - T rue-T ime toolbox is used to reect a more realistic numerical netw ork communication and v alidity of the proposed design method. - The control performance of the proposed method is e v aluated for se v eral industrial protocols: EtherNet/IP protocol, PR OFINET IR T protocol and EtherCA T protocol of the standard IEEE 802.3, the right protocol for a NCS is pro vided . The remainder of this paper is or g anized as follo ws: section 2 introduces the problem statement and preliminaries, our step of adapti v e observ er synthesis is gi v en in section 3. The simulation results based on T rue-T ime toolbox and Matlab/Simulink will be gi v en in section 4 to v erify the ef cienc y of proposed method. Finally , a conclusion is pro vided, including some perspecti v es of this w ork. 2. PR OBLEM FORMULA TION AND PRELIMIN ARIES In this paper , the discrete linear system with output delay is structured as Figure 1; the st ate-space model of the linear plant dynamics (1). x ( k + 1) = Ax ( k ) + A τ k x ( k τ k ) + B u ( k ) + Γ d ( k ) + F Υ( k ) y ( k ) = C x ( k ) (1) Where x ( k ) R n denotes the state v ector , x ( k τ k ) R n denotes the state delay v ector , u ( k ) R m denotes the control input v ector Υ( k ) R q is the f ault v ector , y ( k ) R p denotes the measured output v ector and d ( k ) R m the noise v ector , A , A τ k , B , C and F are matrices of appropriate dimensions. Assumption 1 [13]: It is supposed that random pack et losses e xists in output channel. It is modelled in the system as Bernoulli process. W e dene ˜ y ( k ) the output of the system (with internal noise) and y ( k ) the data used with a probability ¯ β ( r { β k = 1 } = ¯ β ) . If the data is not a v ailable, we will use the preceding data y ( k 1) with probability 1 ¯ β ( r { β k = 0 } = 1 ¯ β ) . The follo wing equations describe this phenomenon. y ( k ) = ¯ β ˜ y ( k ) + (1 ¯ β ) y ( k 1) (2) Where β k { 0 , 1 } obe ys the Bernoulli distrib ution. Assumption 2 [23]: In this paper we will consider that the band-width of the communication netw ork connecting the sensors and the f ault detection module which generates a residue is limited capacity , ϖ ς sensors among p can reach these channels to communicate with the residues generator while the others remain on standby . Similarly , ϖ ϱ from p actuators recei v e their command from controller at each sampling period. Int J Rob & Autom, V ol. 10, No. 3, September 2021 : 261 274 Evaluation Warning : The document was created with Spire.PDF for Python.
Int J Rob & Autom ISSN: 2089-4856 263 where 1 ϖ ϱ m 1 ϖ ς p (3) T aking the phenomenon of sensor and actuator saturation, the functions of saturation ς ( · ) : R m R m and ϱ ( · ) : R m R m are dened as (4). ς ( k ) = ς T 1 ( k ) , ς T 2 ( k ) , · · · , ς T m ( k ) T (4) ϱ ( k ) = ϱ T 1 ( k ) , ϱ T 2 ( k ) , · · · , ϱ T m ( k ) T If we denote by ¯ y ( k ) denotes measurement v ector a v ailable to controller and f ault detecti on module and ¯ u ( k ) denote the control signals generated by controller at discrete time k . Based on the abo v e communi- cation sequence, W e get the relations in (5). ¯ y ( k ) = M ς ( k ) .y ( k ) , M ς diag ( ς i ( k )) (5) u ( k ) = M ϱ ( k ) . ¯ u ( k ) , M ϱ diag ( ϱ i ( k )) From (1), (2), (3), (4) and (5), the dynamics of the netw ork ed control system via a shared communi- cation medium can be described as (6). x ( k + 1) = Ax ( k ) + A τ k x ( k τ k ) + B M ϱ ( t ) ¯ u ( k ) + Γ d ( k ) + F Υ( k ) , y ( k ) = ¯ β ˜ y ( k ) + (1 ¯ β ) y ( k 1) (6) ¯ y ( k ) = M ς ( t ) C x ( k ) Lemma 1 [24] (Schur complement). Gi v en constant matrices of appropriate dimensions B 11 , B 12 and B 22 R n × n , where B 11 = B T 11 , B 22 = B T 22 , then B 12 > 0 , B 11 B 12 B 1 22 B T 12 > 0 if and only if B 11 B 1 22 B T 12 B 22 > 0 . Lemma 2 [25] Gi v en matrices of appropriate dimensions Ξ 11 = Ξ T 11 , Ξ 12 and Ξ 22 . F a function which s atises F = F T I , where is an identity matrix. Then the inequality Ξ 11 + Ξ 12 F Ξ 22 + Ξ T 22 F T Ξ T 12 < 0 . Is not true that, if and only if there e xists a scalar Z such as the inequality is check ed: Ξ 11 + Z Ξ 12 Ξ T 12 + Z 1 Ξ 22 Ξ T 22 < 0 . or equi v alently Ξ 11 Z Ξ 12 Ξ T 22 Z Ξ 12 0 Z Ξ 12 < 0 . where the symbols ( ) denote the symmetric terms. The remote FD dynamic beha viour of NCSs is illustrated in Figure 1. Notably , y ( k ) denotes the ac- tual output signal and ˜ y ( k ) denotes the output signal used by controller , u ( k ) is the control signal produced by controller and ¯ u ( k ) is the actual control input. In this structure the f ault information is not af fected by the communication delay between the sensor and the node of FD unit and communication delay between controller and the node of FD unit. P erformance e valuation of industrial ethernet pr otocols for r eal-time fault detection ... (Samba Aim ´ e Herv ´ e ) Evaluation Warning : The document was created with Spire.PDF for Python.
264 ISSN: 2089-4856 Figure 1. The proposed block diagram of remote FD in netw ork ed control systems with time delays, pack et losses and access constraints 3. RESIDU AL D YN AMIC SYSTEMS In this section, we aim to design an f ault observ er based on discrete-time adapti v e sliding mode for considered netw ork ed system with pack et losses, communication delays and access constraints. The structure of the adapti v e f ault observ er proposed is gi v en by (7). ˆ x ( k + 1) = A ˆ x ( k ) + A τ k ˆ x ( k τ k ) + B M ϱ ( k ) ¯ u ( k ) + L [ y ( k ) ˆ y ( k )] ˆ Υ ( k + 1) = Λ 1 ˆ Υ( k ) + Λ 2 ( y ( k ) ˆ y ( k )) (7) ˆ y ( k ) = ( 1 ¯ β ) M ς ( k ) C ˆ x ( k ) Where ˆ x R n and ˆ y ( k ) R p denote the state estimation for the f ault observ er and estimation of the measurement output respecti v ely; L R n × p is the the observ er g ain matrix and ˆ Υ( k ) is the estimation o f the f ault v ector . This adapti v e sliding mode observ er allo ws to generate a residue which will be analyzed to detect the f aults. It is signicant to note that in the conte xt considered in this paper , Λ 1 , Λ 2 are the f ault detection parameters. Let ε x ( k ) = x ( k ) ˆ x ( k ) and ε y ( k ) = y ( k ) ˆ y ( k ) . According to (1) and (7), we get the estimaror dynamics by (8). ε x ( k + 1) = A (1 ¯ β ) M ς LC ε ( k ) + 1 ¯ β LC x ( k ) + Γ d ( k ) (8) + F ˇ Υ( k ) + A τ k ε x ( k τ k ) ε y ( k ) = (1 ¯ β ) M ς ( k ) C ε x ( k ) (9) where ˘ Υ( k ) = Υ( k ) ˆ Υ( k ) F or the f ault observ er , the logic of f ault detection considered in this w ork is gi v en by (10). J ( k ) > J th Alarm, f ault is detected (10) J ( k ) J th No alarm, f ault is no detected Where J ( k ) is the residual e v aluation function of the residual generator and J th is the threshold are selected as (11). J ( k ) = " n X k =1 r ( k ) T r ( k ) # 1 2 J th = sup d ( k ) I 2 Υ( k )=0 E { J ( k ) } (11) where n is the length of the e v aluation windo w and r ( k )) = ε y ( k ) denotes the residual signal of the system. Int J Rob & Autom, V ol. 10, No. 3, September 2021 : 261 274 Evaluation Warning : The document was created with Spire.PDF for Python.
Int J Rob & Autom ISSN: 2089-4856 265 4. ST ABILITY AN AL YSIS Theor em 1. Consider the system (7) with the gi v en scalar γ > 0 , if there e xist matrices P 1 > 0 , Λ 1 , Λ 2 > 0 and L , such that the follo wing matrix inequality holds. H = Σ 11 γ Σ 12 Σ T 22 γ Σ 12 0 γ Σ 12 < 0 (12) where Σ 11 = P 1 + γ I 0 0 I + γ I , Σ 22 = P 1 0 0 I Σ 21 = ˜ Σ 11 ˜ Σ 12 ˜ Σ 21 ˜ Σ 22 ˜ Σ 12 = Λ 2 (1 ¯ β ) M ς C T ˜ Σ 21 = F T P 1 ˜ Σ 22 = Λ T 1 Then the residual dynamic system (7) is asymptotically stable. Pr oof 1. Choose a L yapuno v functional candidate as (13). V ( k ) = ε T x ( k ) P 1 ε x ( k ) + ˘ Υ T ( k ) ˘ Υ( k ) (13) Then , it can be obtained as (14). E { V ( k + 1) V ( k ) } = E { ε x ( k ) T A (1 ¯ β ) M ς LC T P 1 A (1 ¯ β ) M ς LC ε x ( k ) + 2 ε x ( k ) A (1 ¯ β ) M ς LC T P 1 F ˘ Υ( k ) + ˘ Υ T ( k ) F T P 1 F ˘ Υ( k ) + ˘ Υ T ( k + 1) ˘ Υ( k + 1) ε x ( k τ k ) T A T τ k P 1 A τ k ε x ( k τ k ) + 2 e x ( k ) T ( A (1 ¯ β ) M ς LC ) T P 1 A τ k × e x ( k τ k ) (14) + 2 ε T x ( k )( A (1 ¯ β ) M ς LC ) T ( A (1 ¯ β ) M ς LC ) T P 1 × Γ d ( k ) + 2 e ( k τ k ) T A τ k P 1 Γ d ( k ) + d ( k )] T P 1 d ( k )] + Γ d ( k ) ε x ( k ) T P 1 ε x ( k ) ˘ Υ T ( k ) ˘ Υ( k ) where E n ˘ Υ( k + 1) o = Λ 1 ˜ Υ( k ) Λ 2 ε x ( k ) + Φ ( k ) Φ ( k ) = Λ 1 Υ( k ) + Υ( k + 1) (15) T aking d ( k ) ¯ d , where ¯ d is kno w positi v e constants, it is deri v ed that d ( k )] T P 1 d ( k )] Γ d ( k ) 2 P 1 Γ ¯ d 2 P 1 (16) A (1 ¯ β ) M ς LC T P 1 d ( k )] A (1 ¯ β ) M ς LC T P 1 Γ d ( k ) (17) 2 ε x ( k τ k ) T A T τ k P 1 d ( k )] 2 ε x ( k τ k ) T A T τ k P 1 Γ ¯ d (18) P erformance e valuation of industrial ethernet pr otocols for r eal-time fault detection ... (Samba Aim ´ e Herv ´ e ) Evaluation Warning : The document was created with Spire.PDF for Python.
266 ISSN: 2089-4856 According to (15), (16), (17) and (18). It can be further obtained (19). E { V ( k + 1) V ( k ) } ε x ( k ) T ( A (1 ¯ β ) M ς LC ) T P 1 ( A (1 ¯ β ) M ς LC ) P 1 × ε x ( k ) + 2 ε x ( k )( A (1 ¯ β ) M ς LC ) T P 1 F ˘ Υ( k ) + ˘ Υ T ( k ) × ( F T P 1 Υ( k ) I ) ˘ Υ( k ) + 2 ( A (1 ¯ β ) M ς LC ) T P 1 × ε x ( k ) T Γ ¯ d + 2 ε x ( k τ k ) T A T τ k P 1 (19) × Γ ¯ d + ε x ( k ) T ( A (1 ¯ β ) M ς LC ) T P 1 × ( A (1 ¯ β ) M ς LC ) ε x ( k ) + 2 λ 2 ε x ( k ) T P 1 ε x ( k ) + M T Θ T + Φ ( k ) M T Θ + Φ ( k ) P 1 + Γ ¯ d 2 where, M T = ε x ( k ) T ˘ Υ T ( k ) Θ T = Λ 2 (1 ¯ β ) M ς C T Λ 1 According to the Lemma 2 and (19), it easy to obtain (20). E { V ( k + 1) V ( k ) } M T H M + 2 M T Θ T Φ ( k ) + Φ ( k ) T Φ ( k ) (20) F or the matrix H , it can be obtained by Lemma 1: H = Σ 11 γ Σ 12 Σ T 22 γ Σ 12 0 γ Σ 12 < 0 (21) where Σ 11 = P 1 + γ I 0 0 I + γ I , Σ 22 = P 1 0 0 I , Σ 21 = ˜ Σ 11 ˜ Σ 12 ˜ Σ 21 ˜ Σ 22 , ˜ Σ 11 = A (1 ¯ β ) M ς LC T P 1 , ˜ Σ 12 = Λ 2 (1 ¯ β ) M ς C T , ˜ Σ 21 = F T P 1 , ˜ Σ 22 = Λ T 1 , The proof is completed. Theor em 2. Consider the dynamic system (8). If there e xist matrices L R n × m and η 2 < 1 satisfying the condition. ¯ 11 ¯ 12 ¯ 22 < 0 (22) Where ¯ 11 = η 2 (1 ¯ β ) M ς ( k ) C T (1 ¯ β ) M ς ( k ) C , ¯ 12 = 2 A (1 ¯ β ) M ς LC T , ¯ 22 = 1 2 (1 ¯ β ) M ς ( k ) C T (1 ¯ β ) M ς ( k ) C , then system motion gets into the sliding surf ace in nite time. Int J Rob & Autom, V ol. 10, No. 3, September 2021 : 261 274 Evaluation Warning : The document was created with Spire.PDF for Python.
Int J Rob & Autom ISSN: 2089-4856 267 Pr oof 2. According to [22], the system motion gets into the sliding surf ace in ni te time, then s ( k ) satises. s ( k + 1) s ( k ) (23) the condition (23) can then be reformulated in (24). s ( k + 1) T s ( k + 1) η 2 s ( k ) T s ( k ) = ε T y ( k + 1) ε y ( k + 1) η 2 ε T y ( k ) ε y ( k ) (24) According to (8), then we ha v e s ( k + 1) T s ( k + 1) η 2 s ( k ) T s ( k ) = ε T x ( k + 1)((1 ¯ β ) M ς ( k ) C ) T ((1 ¯ β ) M ς ( k ) C ) × ε x ( k + 1) η 2 ε T x ( k )((1 ¯ β ) M ς ( k ) C ) T (25) × ((1 ¯ β ) M ς ( k ) C ) ε x ( k ) < 0 where η 2 < 1 , then substituting (8) into (26), we can obtain (26). s ( k + 1) T s ( k + 1) η 2 s ( k ) T s ( k ) = ε T x ( k )[( A (1 ¯ β ) M ς LC ) T ((1 ¯ β ) M ς ( k ) C ) T × ((1 ¯ β ) M ς ( k ) C )( A (1 ¯ β ) M ς LC ) η 2 ((1 ¯ β ) M ς ( k ) C ) T ((1 ¯ β ) M ς ( k ) C )] × ε T x ( k ) + ε x ( k τ k ) T A T τ k ((1 ¯ β ) M ς ( k ) C ) T × ((1 ¯ β ) M ς ( k ) C ) ε x ( k τ k ) + d ( k )] T (26) × ((1 ¯ β ) M ς ( k ) C ) T ((1 ¯ β ) M ς ( k ) C ) × Γ d ( k ) + 2 ε T x ( k ) × ( A (1 ¯ β ) M ς LC ) T × ((1 ¯ β ) M ς ( k ) C ) T ((1 ¯ β ) M ς ( k ) C ) A τ k × ε x ( k τ k ) + 2 ε T x ( k ) A (1 ¯ β ) M ς LC T × ((1 ¯ β ) M ς ( k ) C ) T ((1 ¯ β ) M ς ( k ) C d ( k ) + 2 ε T x ( k ) A (1 ¯ β ) M ς LC T A T τ k × ((1 ¯ β ) M ς ( k ) C ) T ((1 ¯ β ) M ς ( k ) C d ( k ) Simolarly , (24) can be obtained (27). s ( k + 1) T s ( k + 1) η 2 s ( k ) T s ( k ) ε T x ( k )[( A (1 ¯ β ) M ς LC ) T ((1 ¯ β ) M ς ( k ) C ) T η 2 ((1 ¯ β ) M ς ( k ) C ) T ((1 ¯ β ) M ς ( k ) C × ( A (1 ¯ β ) M ς LC )((1 ¯ β ) M ς ( k ) C )] ε x ( k )) + 2 ε T x ( k )( A (1 ¯ β ) M ς LC ) T ((1 ¯ β ) M ς ( k ) C ) T × ((1 ¯ β ) M ς ( k ) C ) A τ k ε x ( k τ k ) 2 ε T x ( k ) × ( A (1 ¯ β ) M ς LC ) T ((1 ¯ β ) M ς ( k ) C ) T × ((1 ¯ β ) M ς ( k ) C ) Λ 2 ( k ) 2 ε x ( k τ k ) T (27) × ((1 ¯ β ) M ς ( k ) C ) T ((1 ¯ β ) M ς ( k ) C ) Λ ( k ) One can further get (28). s ( k + 1) T s ( k + 1) η 2 s ( k ) T s ( k ) ε T x ( k )[2( A (1 ¯ β ) M ς LC ) T ((1 ¯ β ) M ς ( k ) C ) T × ((1 ¯ β ) M ς ( k ) C )( A (1 ¯ β ) M ς LC ) (28) η 2 ((1 ¯ β ) M ς ( k ) C ) T ((1 ¯ β ) M ς ( k ) C )] × ε x ( k ) < 0 P erformance e valuation of industrial ethernet pr otocols for r eal-time fault detection ... (Samba Aim ´ e Herv ´ e ) Evaluation Warning : The document was created with Spire.PDF for Python.
268 ISSN: 2089-4856 According to the Lemma 2, we obtain (29). s ( k + 1) T s ( k + 1) η 2 s ( k ) T s ( k ) ε T x ( k ) ¯ Ξ ε x ( k ) < 0 (29) Where ¯ Ξ = ¯ ¯ Ξ 11 ¯ ¯ Ξ 12 ¯ ¯ Ξ 22 , ¯ ¯ Ξ 11 = η 2 ((1 ¯ β ) M ς ( k ) C ) T × ((1 ¯ β ) M ς ( k ) C ) ¯ ¯ Ξ 12 = 2( A (1 ¯ β ) M ς LC ) T ¯ ¯ Ξ 22 = 1 2 ((1 ¯ β ) M ς ( k ) C ) T ((1 ¯ β ) M ς ( k ) C ) This completes the proof. 5. SIMULA TION RESUL TS In this section, we will propose a numerical e xample of simulation to illustrate the ef fecti v eness of the methods presented in this w ork. Let us consider the model of netw ork ed control h ydroelectric po wer plant [20]. The o wchart of the winno wing de vice control and communication netw ork is represented on Figure 2. Figure 2. Schematic diagram of netw ork ed control h ydroelectric po wer plant This s y s tem is been used in [21], [25], for the design A Netw ork ed iterati v e learning f ault Diagnosis algorithm for systems with sensor random pack et losses, time-v arying delays, limited communication and actuator f ailure. The state representation of dynamic model is described as (30). x ( k + 1) = 1 . 1840 0 . 4046 0 0 . 5000 0 0 0 0 . 5000 0 x ( k ) + 1 0 0 u ( k ) y ( k ) = h 0 . 2943 0 . 3382 0 . 0001 i x ( k ) (30) Dene A τ k = 0 . 034 0 0 . 01 0 . 031 0 . 03 0 0 . 04 0 . 05 0 . 01 According to the time scale, we dene the time-v arying communication delays as τ i ( k )( i = 0 , 1 , 2) . Int J Rob & Autom, V ol. 10, No. 3, September 2021 : 261 274 Evaluation Warning : The document was created with Spire.PDF for Python.
Int J Rob & Autom ISSN: 2089-4856 269 Let the f ault signal Υ( k ) be gi v en as (31). Υ( k ) = ( 0 . 5 + 0 . 2 sin ( k ) 122 k 142 0 , others (31) And F = 1 1 1 T The communication constraints is x ed to one channel ( ϖ ς = ϖ ϱ = 1) so the follo wing 3-periodic sequence can be proposed. ς (0) , ς (1) , ς (2) , · · · = 1 0 0 , 0 1 0 , 0 0 1 , 1 0 0 , · · · ϱ (0) , ϱ (1) , ϱ (2) , · · · = 1 0 0 , 0 1 0 , 0 0 1 , 1 0 0 , · · · The random v ariable ¯ β satises the Bernoulli distrib ution, let ¯ β = 0 . 65 . Applying Theorem 1 and 2, we can obtain according to the Matlab LMI toolbox, the desi red P 1 , the observ er g ain L , the scalar η and parameters Λ 1 and Λ 1 as follo ws: P 1 = 0 . 231 0 . 005 0 . 002 0 0 . 0012 0 . 0021 0 0 . 0321 0 . 0063 , L = 0 . 0352 0 . 000011 0 . 0142 , Λ 1 = 0 . 03621 , Λ 2 = 0 . 0073 and η = 1 . 0173 e 3 . W e obtain the Simulink/ true time models of netw ork ed control h ydroelectric po wer plant Figure 3. The true-time netw ork block simulates the access to the medium and allo ws the transmission and the reception of data through the netw ork. T able 1 sho ws the simulation parameter for wireless netw ork block. T able 1. Simulation parameter for netw ork block P arameter V alues Netw ork type 802.15 (LAN) Data rate 200 Mps Minimum frame size 544 bits T ransmit po wer 200 dbm Recei v er signal threshold -48 dbm P ath loss e xponent 33.5 In order to sho w the ef fecti v eness of the approach proposed, the noise signal d ( k ) is a white noise Gaussian of an amplitude of 0.025 (sample time T s = 1 s ). The f ault signal Υ( k ) occurs between the moments 122 th at 157 th steps. The results comprise a pack ets loss at the moments: steps 11 at steps 19 steps, steps 41 at steps 52, steps 63 at steps 68, steps 84 at steps 86, steps 89, steps 101 at steps 108, steps 128, steps 133 at steps 139 and steps 194 at steps 196 Figure 4. Figure 5 sho w the e v olution in real t ime of the actual speed of h ydroturbine and the estimated speed by adapti v e sliding mode observ er with EtherNet/IP protocol, PR OFINET IR T protocol and EtherCA T protocol. The generated residue is illustrated by the Figure 6, which sho ws that the residual signal con v er ges to zero without f aults Figure 7 , then , changes rapidly when the f aults occurre d this for the three communications protocols. Figure 8 illustrate the residual e v aluation function J ( k ) . Figure 9 sho ws that the same f aults is detected at steps 125 with switched ethernet protocol. Figure 10 sho ws the occurrence of f ault can detect the f ault at steps 124 with EtherCA T protocol. P erformance e valuation of industrial ethernet pr otocols for r eal-time fault detection ... (Samba Aim ´ e Herv ´ e ) Evaluation Warning : The document was created with Spire.PDF for Python.
270 ISSN: 2089-4856 Figure 3. Simulink/true-time model of remote FD in netw ork ed control h ydroelectric po wer plant Figure 4. The distrib ution of pack et losses ”1” means pack et recei v ed, ”0” means pack et lost Figure 5. Actual and estimated speed of h ydroturbine Int J Rob & Autom, V ol. 10, No. 3, September 2021 : 261 274 Evaluation Warning : The document was created with Spire.PDF for Python.