Milad Jalali

Bio: Milad Jalali is an academic researcher from University of Waterloo. The author has contributed to research in topics: Model predictive control & Slip (vehicle dynamics). The author has an hindex of 7, co-authored 8 publications receiving 221 citations. Previous affiliations of Milad Jalali include General Motors.

A combined-slip predictive control of vehicle stability with experimental verification

Abstract: In this paper, a model predictive vehicle stability controller is designed based on a combined-slip LuGre tyre model. Variations in the lateral tyre forces due to changes in tyre slip ratios are considered in the prediction model of the controller. It is observed that the proposed combined-slip controller takes advantage of the more accurate tyre model and can adjust tyre slip ratios based on lateral forces of the front axle. This results in an interesting closed-loop response that challenges the notion of braking only the wheels on one side of the vehicle in differential braking. The performance of the proposed controller is evaluated in software simulations and is compared to a similar pure-slip controller. Furthermore, experimental tests are conducted on a rear-wheel drive electric Chevrolet Equinox equipped with differential brakes to evaluate the closed-loop response of the model predictive control controller.

Vehicle Stability Control: Model Predictive Approach and Combined-Slip Effect

Abstract: This article presents a model predictive vehicle stability controller that considers tire force nonlinearities and the combined-slip effect. Loss of cornering forces caused by increased longitudinal slip and changes in the slip angle due to the vehicle lateral response are considered in the prediction model of the controller. The developed controller adjusts tire slip ratios based on forces of the front and rear axles, monitors tire capacities, and normal forces, and exhibits excellent performance in maintaining lateral responses within a stable region. The performance of the proposed predictive controller is assessed in software simulations as well as road experiments in various pure-slip and combined-slip driving scenarios and under different road friction conditions.

A Motion Planning and Tracking Framework for Autonomous Vehicles Based on Artificial Potential Field Elaborated Resistance Network Approach

Abstract: This paper presents a novel motion planning and tracking framework for automated vehicles based on artificial potential field (APF) elaborated resistance approach. Motion planning is one of the key parts of autonomous driving, which plans a sequence of movement states to help vehicles drive safely, comfortably, economically, human-like, etc. In this paper, the APF method is used to assign different potential functions to different obstacles and road boundaries; while the drivable area is meshed and assigned resistance values in each edge based on the potential functions. A local current comparison method is employed to find a collision-free path. As opposed to a path, the vehicle motion or trajectory should be planned spatiotemporally. Therefore, the entire planning process is divided into two spaces, namely the virtual and actual. In the virtual space, the vehicle trajectory is predicted and executed step by step over a short horizon with the current vehicle speed. Then, the predicted trajectory is evaluated to decide if the speed should be kept or changed. Finally, it will be sent to the actual space, where an experimentally validated Carsim model controlled by a model predictive controller is used to track the planned trajectory. Several case studies are presented to demonstrate the effectiveness of the proposed framework.

A comprehensive review on hybrid electric vehicles: architectures and components

Abstract: The rapid consumption of fossil fuel and increased environmental damage caused by it have given a strong impetus to the growth and development of fuel-efficient vehicles. Hybrid electric vehicles (HEVs) have evolved from their inchoate state and are proving to be a promising solution to the serious existential problem posed to the planet earth. Not only do HEVs provide better fuel economy and lower emissions satisfying environmental legislations, but also they dampen the effect of rising fuel prices on consumers. HEVs combine the drive powers of an internal combustion engine and an electrical machine. The main components of HEVs are energy storage system, motor, bidirectional converter and maximum power point trackers (MPPT, in case of solar-powered HEVs). The performance of HEVs greatly depends on these components and its architecture. This paper presents an extensive review on essential components used in HEVs such as their architectures with advantages and disadvantages, choice of bidirectional converter to obtain high efficiency, combining ultracapacitor with battery to extend the battery life, traction motors’ role and their suitability for a particular application. Inclusion of photovoltaic cell in HEVs is a fairly new concept and has been discussed in detail. Various MPPT techniques used for solar-driven HEVs are also discussed in this paper with their suitability.

The effectivness of electronic stability control in reducing real world crashes: a literature review

Abstract: Electronic stability control (ESC) is an evolution of antilock brake technology designed to help drivers maintain control of their vehicles in high-speed or sudden maneuvers and on slippery roads. Manufacturers first began equipping vehicles with ESC in the mid 1990s in Europe, and the technology appeared in other markets several years later. The wider proliferation of ESC across the vehicle fleet has allowed evaluation of its effects in real world crashes in many countries, including Japan, Germany, Sweden, France, Great Britain, and the United States. Studies have examined crash effects on different roadways, using differing analytic methods, different crash severities, and different make/model vehicles including both cars and SUVs. This paper provides a summary of those findings. Most studies find that ESC is highly effective in reducing single-vehicle crashes in cars and SUVs. Fatal single-vehicle crashes involving cars are reduced by about 30-50 percent and SUVs by 50-70 percent. Fatal rollover crashes are estimated to be about 70-90 percent lower with ESC regardless of vehicle type. A number of studies find improved effectiveness in reducing crashes when road conditions are slippery. There is little or no effect of ESC in all multi-vehicle crashes; however, there is a 17-38 percent reduction in more serious, fatal multi-vehicle crashes. Given the extraordinary benefits of ESC in preventing crashes, the implementation of ESC should be accelerated to include the full range of vehicles in both developed and developing markets.

Model Predictive Control for integrated lateral stability, traction/braking control, and rollover prevention of electric vehicles

Abstract: This study presents an integrated multi-objective controller for electric vehicles ( EVs) to achieve four main control objectives concurrently, i.e. slip control in traction and braking, lateral st...