Ryerson University

About: Ryerson University is a education organization based out in Toronto, Ontario, Canada. It is known for research contribution in the topics: Computer science & Population. The organization has 7671 authors who have published 20164 publications receiving 394976 citations. The organization is also known as: Ryerson Polytechnical Institute & Ryerson Institute of Technology.

An Optimal Frequency Control Method Through a Dynamic Load Frequency Control (LFC) Model Incorporating Wind Farm

Abstract: In a high penetrated wind farm power system, wind farms can collaborate to control the power system frequency as like as conventional units. This paper presents a novel model to control the frequency of the wind farm connected to conventional units. Throughout the proposed frequency control, the integral controller, washout filter, and the PID controller could determine the active power variation value in different situations. In fact, a PID controller makes the wind farm aware of power variations. To improve the efficiency of the model, the defined frequency control parameters (i.e., PID coefficients) are optimized based on a multiobjective function using particle swarm optimization algorithm. This study has a unique perspective based on the wind farm collaboration through inertia control, primary frequency control, and supplementary frequency control of the system. A swift power reserve in a stable condition is needed in which wind farm can ameliorate the system frequency response. It is worth saying that the wind farm consists of variable speed turbines, such as a doubly fed induction generator, or a permanent magnet synchronous generator. To assess the performance of the proposed model, it is applied to a typical two-area system and the results are compared.

Foot-terrain interaction mechanics for legged robots: Modeling and experimental validation

Abstract: Contact mechanics plays an important role in the design, performance analysis, simulation, and control of legged robots. The Hunt-Crossley model and the Coulomb friction model are often used as black-box models with limited consideration of the properties of the terrain and the feet. This paper analyzes the foot-terrain interaction based on the knowledge of terramechanics and reveals the relationship between the parameters of the conventional models and the terramechanics models. The proposed models are derived in three categories: deformable foot on hard terrain, hard foot on deformable terrain, and deformable foot on deformable terrain. A novel model of tangential forces as the function of displacement is proposed on the basis of an in-depth understanding of the terrain properties. Methods for identifying the model parameters are also developed. Extensive foot-soil interaction experiments have been carried out, and the experimental results validate the high fidelity of the derived models.

Effects of uncertainty on a tire closed-loop supply chain network

Abstract: In a closed-loop supply chain (CLSC) network, there are both forward and reverse supply chains. In this research, a tire remanufacturing CLSC network is designed and optimized based on tire recovery options. The objective of the optimization model is to maximize the total profit. The optimization model includes multiple products, suppliers, plants, retailers, demand markets, and drop-off depots. The application of the model is discussed based on a realistic network in Toronto, Canada using map. In addition, a new decision tree-based methodology is provided to calculate the net present value of the problem in multiple periods under different sources of uncertainty such as demand and returns. Furthermore, the discount cash flow is considered in the methodology as a novel innovative approach. This methodology can be applied in comparing the profitability of different design options for CLSCs.