{"title":"Skid control enhancement for small electric vehicle by using sliding mode control strategy","authors":"S. M. Asyraf, P. M. Heerwan, M. I. Ishak","doi":"10.23919/SICEISCS.2018.8330169","DOIUrl":"https://doi.org/10.23919/SICEISCS.2018.8330169","url":null,"abstract":"Small electric vehicle (EV) with two in-wheel motors employed hydraulic brake system at the front tires and mechanical brake system at the rear tires. The mechanical brake system is installed at the rear tire due to the space limitation for the hydraulic brake system. Although mechanical brake system is compact, the response performance of mechanical brake system is lower than hydraulic brake system. During braking in slippery condition, the stability and safety of small EV will be lost. In this study, to enhance the braking performance of small EV, the sliding mode control (SMC) approach is proposed. The slip ratio is used in the SMC control method to determine the sliding condition of the vehicle. If the slip ratio is not in the optimum range, the SMC will be activated to control the valve in the hydraulic control unit. Based on the signal from the SMC, the valve will open or close to increase, decrease or hold the brake pressure. The analysis has been done in the Matlab Simulink and the result shows that by using SMC, the tires were not lockup and the slip ratio is in the optimum range.","PeriodicalId":122301,"journal":{"name":"2018 SICE International Symposium on Control Systems (SICE ISCS)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131467144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"H2 state-feedback synthesis for discrete-time systems under positivity constraint","authors":"Y. Ebihara, Patrizio Colanoli, J. Geromel","doi":"10.23919/SICEISCS.2018.8330154","DOIUrl":"https://doi.org/10.23919/SICEISCS.2018.8330154","url":null,"abstract":"This paper is concerned with the H2 state-feedback synthesis problem for discrete-time systems under positivity constraint on the closed-loop systems. This problem is believed to be a non-convex problem and hence exact treatment is not known to this date. With this difficulty in mind, in this paper, we first derive semidefinite programs (SDPs) for the computation of the upper bounds of the achievable H2 performance as well as suboptimal gains. However, if we merely rely on the upper bound computation, we cannot draw any definite conclusion on the quality of the computed suboptimal gains. Thus the main issue of the present paper is the lower bound computation, and to this end we derive an SDP for that computation via specific treatment of the finite impulse resonse (FIR) with the idea of time-varying gain synthesis. We show that the lower bounds become tighter as we increase the length of the FIR. By numerical examples we show the soundness of the proposed strategy with upper and lower bounds computation.","PeriodicalId":122301,"journal":{"name":"2018 SICE International Symposium on Control Systems (SICE ISCS)","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133448572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}