Using fully variable valve control for cylinder-individual reference tracking with emission-optimal internal exhaust gas recirculation

A fully variable valve train significantly increases the degree of freedom of the control of internal combustion engines. Cylinder deactivation, thermal management, alternative combustion strategies, and minimized pumping losses are just a few examples enabled by freely adaptable intake and exhaust valve timings. This paper presents a method to achieve the accurate tracking of load trajectories under stoichiometric conditions. A feedback controller is designed with a mixed-sensitivity H∞ synthesis method. The underlying system plant is modeled by a combination of a mean-value model of the cylinder-internal processes and a neural network to map the correlation between valve timings and cylinder charge. All experiments are conducted on a test bench with a spark-ignited engine equipped with an internally developed fully variable valve train called FlexWork. With this method, a mean absolute error of 0.07bar in indicated mean pressure and of 0.009 in air–fuel equivalence ratio is achieved for the tracking of the reference trajectory. Furthermore, a cost function dependent online optimization of the internal exhaust gas recirculation is conducted without affecting the tracking performance of the load and stoichiometry. Depending on the parametrization of the cost function, nitrogen oxide or hydrocarbon pollutants can be reduced by up to 46% or 17%, respectively.ISSN:0967-0661ISSN:1873-693

Feasibility Analysis of a Self-Reinforcing Electroadhesive Rotational Clutch 2021

Building upon recent advancements in linear electroadhesive clutch materials and performance, this paper examines the feasibility of a self-reinforcing electroadhesive rotational clutch using a simple model. The design aims to deliver improvements in applications where performance is limited by the torque-to-power and torque-to-mass ratios offered by conventional electromagnetic or magnetorheological clutches. The performance of the self-reinforcing design is related to the device's geometric parameters and hence the robustness of clutch configurations is examined by modeling the system parameters as having stochastic properties. A design example based on the clutch requirements of a gyroscopic balance assistance device is analyzed. The analysis predicts that substantial improvements in torque-to-power and torque-to-mass ratios are possible with the presented design compared to industry-leading rotational clutches

Feasibility analysis of a self-reinforcing electroadhesive rotational clutch

Building upon recent advancements in linear electroadhesive clutch materials and performance, this paper examines the feasibility of a self-reinforcing electroadhesive rotational clutch using a simple model. The design aims to deliver improvements in applications where performance is limited by the torque-to-power and torque-to-mass ratios offered by conventional electromagnetic or magnetorheological clutches. The performance of the self-reinforcing design is related to the device's geometric parameters and hence the robustness of clutch configurations is examined by modeling the system parameters as having stochastic properties. A design example based on the clutch requirements of a gyroscopic balance assistance device is analyzed. The analysis predicts that substantial improvements in torque-to-power and torque-to-mass ratios are possible with the presented design compared to industry-leading rotational clutches.Accepted Author ManuscriptBiomechatronics & Human-Machine Contro