摘要:針對具有控制輸入約束的車隊(duì)系統(tǒng),提出了基于模型預(yù)測控制的分布式一致性算法.考慮車隊(duì)行駛過程 中存在多種通信方式,建立車輛系統(tǒng)二階動(dòng)力學(xué)模型.為了使得整個(gè)車隊(duì)系統(tǒng)實(shí)現(xiàn)協(xié)同控制,建立穩(wěn)定性成本 代價(jià)函數(shù),應(yīng)用模型預(yù)測控制和滾動(dòng)時(shí)域策略確保系統(tǒng)穩(wěn)定性和優(yōu)化問題的可解性,進(jìn)而使得系統(tǒng)滿足一致性 性能.通過仿真驗(yàn)證了本文所提方法的可行性.
關(guān)鍵詞:車隊(duì)系統(tǒng);一致性;穩(wěn)定性;預(yù)測控制
中圖分類號:U495
文獻(xiàn)標(biāo)志碼:A
Vehicle Fleet System Consensus Control Based on Model Predictive Control
LI Zhuang, FANG Zhen-qi, MENG Qiu, XUE Xiang, CHEN Zhang-bao
(School of Electronics and Electrical Engineering, Bengbu College, Bengbu 233030, Anhui, China)
Abstract:For vehicle fleet systems with control input constraints, a distributed consensus algorithm based on model predictive control is proposed in this paper. Considering the existence of various communication modes in the process of convoy driving, the second-order dynamics model of vehicle system is established. In order to realize the cooperative control of the whole fleet system, the optimization problem is established by defining the stability cost function and location constraint, and the model predictive control and the receding horizon strategy are applied to ensure the stability of the system and the solvable optimization problem, so that the system can meet the consistency performance. The feasibility of the proposed method is verified by simulation.
Key words:fleet system; consensus; stability; predictive control
隨著國家經(jīng)濟(jì)發(fā)展,汽車使用量逐漸增加,對道路的容納量造成一定挑戰(zhàn).車輛在行駛過程中,不合理的安全間距也會(huì)降低道路的利用率,阻礙通行.近年來,車輛隊(duì)列協(xié)同控制方式廣泛用于車輛隊(duì)列研究中,該策略可提高車輛控制性能,在確保車隊(duì)安全運(yùn)行的條件下,使得車隊(duì)中的每一輛車達(dá)到期望速度,實(shí)現(xiàn)協(xié)同控制[1-2].
在車輛協(xié)同控制過程中,存在多種物理約束條件,例如速度、加速度等,為了有效解決約束和相關(guān)參數(shù)計(jì)算,眾多學(xué)者應(yīng)用分布式模型預(yù)測控制來研究車輛協(xié)同控制[3-6].文獻(xiàn)[3]在確保安全 性的條件下,基于模型預(yù)測控制策略,設(shè)計(jì)通信延 遲分布式控制器,使得車隊(duì)實(shí)現(xiàn)一致性控制.文獻(xiàn)[4]考慮燃油經(jīng)濟(jì)和協(xié)同穩(wěn)定性問題,設(shè)計(jì)分布式 協(xié)同算法,在確保系統(tǒng)穩(wěn)定性的基礎(chǔ)下,實(shí)現(xiàn)節(jié)能 作用.文獻(xiàn)[5]針對車輛系統(tǒng)中存在的多個(gè)目標(biāo)問 題,設(shè)計(jì)基于模型預(yù)測控制的字典序列算法,求解 多目標(biāo)問題.分布式模型預(yù)測控制在車隊(duì)控制研 究中取得了較多成果,可有效解決車隊(duì)協(xié)同控制 問題[6-8].
除上述工作外,一致性協(xié)同控制在多智能體 中也得到廣泛研究[9-10].文獻(xiàn)[9]考慮線性多智能 體系統(tǒng),在一定條件下忽略時(shí)變參數(shù)影響,研究系 統(tǒng)穩(wěn)定性和控制性能指標(biāo).文獻(xiàn)[11]應(yīng)用圖論描 述系統(tǒng)通信方式,針對一、二階動(dòng)力學(xué)模型,設(shè)計(jì) 分散式控制策略,并采用數(shù)學(xué)幾何方式,實(shí)現(xiàn)系統(tǒng) 的穩(wěn)定性和一致性.同時(shí)一致性算法也用于智能 體的集群和編隊(duì)問題中,使得系統(tǒng)滿足性能要 求[1].在車隊(duì)控制系統(tǒng)中,部分學(xué)者設(shè)計(jì)一致性 協(xié)議來確保車隊(duì)滿足一致性,根據(jù)車輛通信方式 的不同,設(shè)計(jì)不同的分布式協(xié)議.文獻(xiàn)[13]依據(jù)車 輛實(shí)時(shí)速度設(shè)計(jì)一致性算法,使車隊(duì)滿足一致性 要求.文獻(xiàn)[14]用車頭時(shí)距策略,研究車隊(duì)一致性 問題.上述部分工作應(yīng)用線性化方法,忽略了參數(shù) 和系統(tǒng)的非線性,在理論推導(dǎo)和證明過程中更為 方便,但當(dāng)參數(shù)權(quán)重較大時(shí),線性化會(huì)存在約束條 件,在一定程度上影響實(shí)際控制.
在車隊(duì)研究中,眾多學(xué)者應(yīng)用模型預(yù)測控制 算法,在解決車隊(duì)物理約束問題的同時(shí),使得車隊(duì) 滿足良好的控制性能,實(shí)現(xiàn)車隊(duì)穩(wěn)定性和一致性 控制.
本文針對具有控制約束的車隊(duì)系統(tǒng),設(shè)計(jì)了 分布式模型預(yù)測控制一致性策略,使得車隊(duì)系統(tǒng) 在不同通信方式下,滿足系統(tǒng)穩(wěn)定性和車隊(duì)一致 性,實(shí)現(xiàn)車隊(duì)協(xié)同控制.
4.2車輛之間任意通信方式
考慮圖1(b)的通信方式,則成本函數(shù)在公式(4)基礎(chǔ)上,附加與本車之間存在通信的車輛狀態(tài) 信息,仿真結(jié)果如圖4-圖5所示.
由圖4-圖5可知,相對位置偏差收斂到0; 起始時(shí)刻每輛車具有相同速度,并與期望速度相 差1m/s,經(jīng)過一段時(shí)間后,車隊(duì)速度達(dá)到期望速 度,車輛之間滿足安全車間距,車隊(duì)實(shí)現(xiàn)一致性.
5結(jié)語
針對具有控制輸入約束的車隊(duì)系統(tǒng),設(shè)計(jì)了 分布式一致性控制算法,單車子系統(tǒng)的成本函數(shù) 包含與之存在通信的車輛狀態(tài)信息,應(yīng)用模型預(yù) 測控制中三要素法,建立了系統(tǒng)穩(wěn)定性和優(yōu)化問 題可行性的充分條件;通過數(shù)值仿真驗(yàn)證了所提 策略的有效性,車隊(duì)系統(tǒng)實(shí)現(xiàn)跟蹤穩(wěn)定性和一致 性.在未來工作中,將進(jìn)一步研究車隊(duì)系統(tǒng)中多目 標(biāo)問題和通信時(shí)延問題,該課題也值得繼續(xù)學(xué)習(xí).
參考文獻(xiàn):
[1] LI S. Performance enhanced predictive control for adaptive cruise control system considering road elevation information [J]. IEEE Trans Intell Vehicles,2017,2(3):150-160.
[2] DUNBAR W B,CAVENEY D S. Distributed receding horizon control of vehicle platoons: stability and string stability [J]. IEEE Transactions on Automatic Control,2012,57(3):620-633.
[3]朱永薪,李永福,朱浩,等.通信延時(shí)環(huán)境下基于觀測 器的智能網(wǎng)聯(lián)車輛隊(duì)列分層協(xié)同縱向控制[J].自動(dòng)化學(xué)報(bào),2023,49(48):1785-1798.
[4]HE D, QIU T, LUO R. Fuel efficiency - oriented platooning control of connected nonlinear vehicles: a distributed economic MPC approach[J]. Asian Journal of Control,2020,22(4):1628-1638.
[5]趙樹恩,冷姚,邵毅明.車輛多目標(biāo)自適應(yīng)巡航顯式模 型預(yù)測控制[J].交通運(yùn)輸工程學(xué)報(bào),2020,20(3):206-216.
[6] LI H,SHI Y,YANG W.Distributed receding horizon control of constrained nonlinear vehicle formations with guaranteed Y-gain stability [J]. Automatica,2016,68:148-154.
[7] ZHENG Y,LI S, LI K,et al. Distributed model predictive control for heterogeneous vehicle platoons under unidirectional topologies [J]. IEEE Transaction Control Systems Technology,2017,25(3):899-910.
[8]彭利明,孫駿,魏子淳,等.基于模型預(yù)測控制的智能 網(wǎng)聯(lián)車隊(duì)異步避障策略[J].合肥工業(yè)大學(xué)學(xué)報(bào)(自然 科學(xué)版),2023,46(11):1454-1459.
[9] WANG J G,LUO X Y,WONG W C,et al. SpecifiedTime vehicular platoon control with flexible safe distance constraint [J]. IEEE Trans Veh Tech,2019,68(11):10489-10520.
[10] FIROOZNIA A,PLOEG J,WOUW N V,de,et al,Co-Design of controller and communication topology for vehicle platooning [J]. IEEE Trans Intell Transp Syst,2017,18(10):2728-2739.
[11] FERRARI-TRECATE G, GALBUSERA L, MAR-CIANDI M,et al. Model predictive control schemes for consensus n multi-agent systems with single-and double-integrator dynamic [J]. IEEE Trans Autom Control,2009,54(11):2560-2572.
[12] ZHAN J,LI X. Flocking of multi-agents systems via model predictive control based on position-only[J]. IEEE Trans Industrial Informat-measurements ics,2013,9(1):377-385.
[13] ZEGERS J C,KAZEROONI E S,PLOEG J.Consen-sus control for vehicular platooning with velocity constraints [J]. IEEE Transactions on Control Systems Technology,2018,26(5):1592-1605.
[14] SANTINI S,SALVI A, VALENTE A S. A consen-sus-based approach for platooning with intervehicular communications and its validation in realistic scenarios [J]. IEEE Transactions on Vehicles Technol-ogy,2017,66(3):1985-1999.
[15] CHEN H, ALLGOWER F. A quasi-infinite horizon nonlinear model predictive control scheme with guaranteed stability[J]. Automatica,1998,34(10):1205-1217.
蘭州文理學(xué)院學(xué)報(bào)(自然科學(xué)版)2024年3期