tailieunhanh - Petri nets applications Part 16

Tham khảo tài liệu 'petri nets applications part 16', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 592 Petri Nets Applications Discrete part Continuous part m0 1 0 1 0 mc T0 C0 v V1 v2 p1 is 0 md 1 0 1 0 mc T1 0 v P P1 b t6 fires md 1 0 0 1 mc t2 0 v2 V1 0 Fig. 2. Phase diagram of Hybrid Petri Net model Fig. 3. Behavior of Hybrid Petri Net model t n Pd or c t t n Pc. Similar notation may be used for presets and postsets of places. The function C and D specify the firing speeds associated to the continuous transitions and the timing associated to the timed discrete transitions. For any continuous transition ti we let C ti Vi Vi where Vi and Vi represent the minimum and maximum firing speed of transition ti. We associate to the timed discrete transition its firing delay where the firing delay is short enough and the state is preserved until next sampling instant. The acquisition of firing sequence of the discrete transition at every sampling instant is applied to a variety of scheduling and control problems. The marking M Me I Md has both continuous m dimension and discrete n dimension parts. Consider a simple example of First-Order Hybrid Petri Net model where the control switch is represented with two discrete transitions and two discrete places connected to the continuous transition. In P1 is the continuous place with the initial marking mc T0 mp1 C0 and P2 P3 P4 and P5 are the discrete places with the initial marking md ĩ0 mp2 mp3 mp4 mp5 1 0 1 0 . We assume V1 a V2b where V1 and V2 are firing speed of t1 and Traffic Network Control Based on Hybrid System Modeling 593 Section 1 Section 2 Section 3 Section 4 Section 5 Fig. 4. Traffic network Fig. 5. Hybrid Petri Net model of traffic network t2 respectively a and b are the arc weights given by the incidence relationship. The behavior is illustrated in and . Figure 5 shows the HPN model for the road of . In each section i of li-meters long constitutes the straight road and two traffic lights are installed at the point of crosswalk. pc Pc represents each section of the road and .