SYMar 23, 2017
Hybrid control strategy for a semi active suspension system using fuzzy logic and bio-inspired chaotic fruit fly algorithmVikram Bhattacharjee, Debanjan Chatterjee, Orkun Karabasoglu
This study proposes a control strategy for the efficient semi active suspension systems utilizing a novel hybrid PID-fuzzy logic control scheme .In the control architecture, we employ the Chaotic Fruit Fly Algorithm for PID tuning since it can avoid local minima by chaotic search. A novel linguistic rule based fuzzy logic controller is developed to aid the PID.A quarter car model with a non-linear spring system is used to test the performance of the proposed control approach. A road terrain is chosen where the comfort and handling parameters are tested specifically in the regions of abrupt changes. The results suggest that the suspension systems controlled by the hybrid strategy has the potential to offer more comfort and handling by reducing the peak acceleration and suspension distortion by 83.3 % and 28.57% respectively when compared to the active suspension systems. Also, compared to the performance of similar suspension control strategies optimized by stochastic algorithms such as Genetic Algorithms (GA), Particle Swarm Optimization (PSO) and Bacterial Foraging Optimization (BFO), reductions in peak acceleration and suspension distortion are found to be 25%, 32.3%, 54.6% and 23.35 %, 22.5%, 5.4 % respectively.The details of the solution methodology have been presented in the paper.
1.3CRApr 17
Polynomial Multiproofs for Scalable Data Availability Sampling in Blockchain Light ClientsRachit Anand Srivastava, Vikram Bhattacharjee, Will Arnold et al.
Light clients are essential for scalable blockchain systems because they verify data availability without downloading full blocks. In data availability sampling based systems, sampled cells are retrieved from a peer-to-peer network and verified against cryptographic commitments. A common deployment pattern associates each sampled cell with an independent Kate-Zaverucha-Goldberg (KZG) proof, creating substantial cumulative bandwidth, storage, and verification overhead. This paper studies polynomial multiproofs (PMP) as a mechanism for reducing these costs in blockchain light clients. We present a design in which multiple sampled cell evaluations are verified using a single aggregated proof over a shared evaluation micro-domain and describe the corresponding changes to proof generation, dissemination, retrieval, and verification in a peer-to-peer light-client stack. We instantiate and evaluate the design in Avail, a modular data availability layer for blockchains, as a case study. The results show lower proof bytes, lower verifier CPU and memory usage, and deployment-level infrastructure cost reductions of up to 45% relative to a per-cell baseline, while also clarifying the trade-offs introduced by grouped retrieval.