MB-CVT电液控制系统智能优化设计

为了提高配有金属带式无级变速器车型燃油经济性,提出基于滑模极值搜索理论的控制算法和基于滑模极值搜索控制与传统夹紧力控制相结合的一体化式联合控制方法;设计了滑模极值搜索控制和传统液压控制合为一体化的联合控制系统。建立具有非线性、离散性的数学模型;分析无级变速器传动效率和金属带滑差率在一定速比下存在特殊曲线关系;测试主/从动轮夹紧力比值系数,完成了速比跟踪控制器及变化率控制流程设计。依据滑模极值搜索算法原理,完成了滑模极值搜索控制器设计。在具有环境仓的转鼓试验台上进行整车试验,试验结果表明:采用一体化式控制的金属带式无级变速器车型油耗为7.18L/100km,比传统控制系统的油耗降低约5.64%;主、从动压力安全系数倒数指标均小于1。满足整车提高燃油经济需求的可靠性、稳定性及优化性能。

Intelligent optimization design for MB-CVT electro-hydraulic control system

Purpose:to improve the fuel economy of vehicles with MB-CVT,a control algorithm based on sliding mode extremum seeking (SMES) theory and an integrated control method based on combination of SMES control and traditional clamping force control were put forward.Method:designed the integrated control system based on a combination of SMES control and traditional hydraulic control,and established a mathematical model with nonlinearity and discreteness;analyzed the special curvilinear relationship between the efficiency of continuously variable transmission (CVT) and slip ratio of metal band (MB);tested the clamping force ratio coefficient of drive/driven wheel,and achieved the design for speed ratio tracking controller and changed ratio flow;completed the SMES controller design based on principle of the SMES algorithm,and carried out whole vehicle testing in the running drum tester with environment chamber.Conclusion:the test results show that fuel consumption for vehicle with MB-CVT which adopts the integrated control is 7.18L/100km,5.64％ lower than fuel consumption of traditional control system,and inverse indicator for pressure safety index of both the drive wheel and driven wheel is lower than 1,which meets the reliability,stability and optimal performance for improvement of whole-vehicle fuel economy.