Optimal cam design and system control for an electromechanical engine valve drive

Nonlinear System Modeling, Optimal Cam Design, and Advanced System Control for an Electromechanical Engine Valve Drive

“…9. For a given NMT function, the cam slot surface slope, ) tan(α , and its variation, ) cos(α , are derived in [21] and [22], which turn out to be nonlinear functions with respect to position.…”

“…Therefore, in order to identify system parameters and predict system performance, we have to rely heavily on numerical simulation owing to the inherent nonlinearity of the whole system. The setup of the numerical simulation, experimental apparatus, extraction of friction coefficients, and validation of the proposed nonlinear friction model by comparing simulation to experimental results is discussed in [21and [22]. Further investigation shows that the nonlinear friction force portion in the θ -domain is a dominant part compared to the linear friction portions both in the θ -domain and in the z-domain.…”

A custom-designed limited-angle actuator for an electromechanical engine valve drive. Part I: Conceptual design

“…When the motor swings back and forth within the angle range limited by the cam slot design, the roller follower moves back and forth within the slotted cam, allowing the valve to move up and down between fully open and fully closed positions. In order to achieve soft landing at the end of transitions, a low torque requirement during transitions, and zero power consumption between transitions, the mechanical transformer was designed with an intentionally nonlinear characteristic, as discussed previously [17]- [22]. This EMV system is referred to hereafter as the NMT EMV system.…”

“…3, the test stand consists of a computer-controlled digital signal processor (DSP) board (the DS1104 from dSPACE, Novi, MI), a motor drive, a shear-force motor with an optical shaft angle encoder, a valve-spring assembly, and a disk cam and roller follower to implement the NMT. More details on the experimental design can be found in [17]- [22]. Two commercial motors, shown in Fig.…”

A Novel Design Concept of Electromagnetic Valve Actuator with High Starting Force

“…Namely, finding the appropriate solution for the independent valve actuation system would significantly contribute to the improvement of the performance, energy conversion and utilization of the existing conventional ICE (gasoline and diesel engines) and facilitate the fulfilment of the requirements defined by new environmental regulations [6]. In addition, it would enable further development and the introduction to the market of novel ICE engine operation mode, such as pneumatic hybrid [7], homogeneous charge compression ignition (HCCI) combustion [8,9], and 2/4 stroke operation mode [10], which have already been scientifically evaluated.…”