Development and Experimental Validation of an Adaptive, Piston-Damage-Based Combustion Control System for SI Engines: Part 2—Implementation of Adaptive Strategies

This work focuses on the implementation of innovative adaptive strategies and a closed-loop chain in a piston-damage-based combustion controller. In the previous paper (Part 1), implemented models and the open loop algorithm are described and validated by reproducing some vehicle maneuvers at the engine test cell. Such controller is further improved by implementing self-learning algorithms based on the analytical formulations of knock and the combustion model, to update the fuel Research Octane Number (RON) and the relationship between the combustion phase and the spark timing in real-time. These strategies are based on the availability of an on-board indicating system for the estimation of both the knock intensity and the combustion phase index. The equations used to develop the adaptive strategies are described in detail. A closed-loop chain is then added, and the complete controller is finally implemented in a Rapid Control Prototyping (RCP) device. The controller is validated with specific tests defined to verify the robustness and the accuracy of the adaptive strategies. Results of the online validation process are presented in the last part of the paper and the accuracy of the complete controller is finally demonstrated. Indeed, error between the cyclic and the target combustion phase index is within the range ±0.5 Crank Angle degrees (°CA), while the error between the measured and the calculated maximum in-cylinder pressure is included in the range ±5 bar, even when fuel RON or spark advance map is changing.

Geometric design of rotary retractable plate structures based on parallelogram closed-loop chain linkages

For large-span retractable roof structures, the mechanism should be simple and efficient for the convenience of motion control. The kinematic characteristics of parallelogram closed-loop chain linkages (PCCL) show that a set of the angulated beams of PCCL rotates around the fixed points, which is suitable for retractable structures. This paper focuses on the geometrical design of the rotary retractable plate structures (RRPS), which evolves from PCCL by replacing the rotation angulated beams with cover plates. Each plate of RRPS has a fixed support and all the plates rotate simultaneously with a single DOF. The fixed points used as supports for cover plates to improve the stability and simplify the motion control of the system restrict the open area of the RRPS. By adjusting the contact boundaries of the cover plates, an optimisation method is proposed to increase the open area of the RRPS after fully deployed. The design approach is successfully extended to both symmetrical and asymmetrical RRPS. An example is carried out to demonstrate the feasibility of the approach and a simple physical model is manufactured to validate the design result in the example.

Structural Diversity of Six Coordination Polymers Based on the Designed X-Shaped Ligand 1,1,1,1-Tetrakis[(3-pyridiniourea)methyl]methane

In this study, six coordination polymers (CPs), {[Ag2(L)(CF3SO3)]·CF3SO3·2H2O·DMF}n (1), {[Ag(L)]·SbF6·4DMF·H2O}n (2), {[Zn(L)0.5(I)2]·3.75H2O}n (3), {[Cd2(L)(I)4(H2O)(DMF)]·4H2O·3DMF}n (4), {[Hg2(L)(I)4]·H2O·4DMF}n (5) and {[Hg2(L)(Cl)4]·2H2O·3DMF}n (6), were obtained based on the designed X-shaped urea-based ligand. X-ray single crystal diffraction analysis revealed that complex 1 displayed a 3D (3,4)-connected {6·82}{64·82}-tcj net. Complex 2 featured a 2D 4-connected {43·63} sheet. Complexes 3 and 5 exhibited a 1D polymeric loop chain. Complex 4 displayed a 1D polymeric fishbone chain. Complex 6 showed a 2D 4-connected {44·62}-sql sheet. Structural comparison revealed that not only the metal ions, but also the anions played crucial roles in the control of final structures.

A loop chain and a three-dimensional network assembled from a multi-dentate nitronyl nitroxide radical and M(hfac)2 (M = CoII, CuII)

A unique loop chain and a 3D framework involving multidentate nitronyl nitroxide are reported and a Co complex exhibits slow magnetic relaxation.

THE GOLD AND GARNET CHAIN FROM ISENBÜTTEL, GERMANY: A POSSIBLE PIN SUITE WITH ANGLO-SAXON PARALLELS

The ‘Isenbüttel gold necklace’, now in the Lower Saxony State Museum in Hanover, was found almost a century ago in Lower Saxony, an area with no history of early medieval gold finds or richly furnished burials. As no parallels are known for the object, scholars have long debated the dating, provenance and function of this unique loop-in-loop chain, with its animal-head terminals and garnet cloisonné. Recent excavations of Anglo-Saxon cemeteries dating to the seventh century have, however, added new finds to the small corpus of objects known as ‘pin suites’, consisting of comparatively short pins perhaps designed to fix a veil or a light shawl in the collar area, with ornate pinheads, linked by chains. This paper focuses on Anglo-Saxon pin suites from high-status burials of the second half of the seventh century and seeks to set the finds group in its wider social and historical context, revealing the far-reaching relationships that existed between early medieval elites.

Dynamic Analysis and Simulation of 4R 3-DOF Wrists

In this paper, a systematic algorithm for the dynamic analysis of 4R 3-DOF wrists is presented. Based on the theory of graph, kinematics is completed. Links are divided into primary links and secondary links. The generalized inertia force of the system results from the motions of primary links and secondary links. The concept of virtual 3R 3-DOF open-loop chain and additional link are introduced to describe the primary links. The generalized inertia forces of 3R 3-DOF open-loop chain, additional link and secondary links are derived by Lagrangian formulation, respectively, based on their location in the wrist. Then the dynamic equation of 4R 3-DOF wrists is got by making a combining. A simulation is performed to illustrate the efficiency of the algorithm.

The QuadroG Robot, a Parallel Robot With a Configurable Platform for Haptic Applications

This paper explores the fundamentals of parallel robots with configurable platforms (PRCP), as well as the design and the kinematic analysis of those. The concept behind PRCP is that the rigid (non-configurable) end-effector is replaced by a closed-loop chain, the configurable platform. The use of a closed-loop chain allows the robot to interact with the environment from multiple contact points on the platform, which reflects the presence of multiple end-effectors. This results in a robot that successfully combines motion and grasping capabilities into a structure that provides an inherent high stiffness. This paper aims to introduce the QuadroG robot, a 4 degrees of freedom PRCP which finely merges planar motion together with grasping capabilities.