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Integration of torque blending and slip control using real-time nonlinear model predictive control
Published in Johannes Edelmann, Manfred Plöchl, Peter E. Pfeffer, Advanced Vehicle Control AVEC’16, 2017
M. Sofian Basrah, E. Siampis, E. Velenis, D. Cao, S. Longo
Vehicle electrification is part of the major initiative by automotive manufacturers as solution to emission issues and the diminishment of the fossil fuel resources (Chan 2007). Electrified vehicles are equipped with redundant braking actuators, namely hydraulic brakes and a regenerative braking system using electric motors (EMs). This creates the opportunity for research into brake torque blending for Anti-lock Braking System (ABS) in a hybrid braking system. The existence of the new actuator creates the opportunity not only to increase energy efficiency but to enhance the performance of the safety aspect of the vehicle (Crolla & Cao 2012). ABS is an important feature of active vehicle safety to avoid wheel locking while maintaining vehicle steerability and stability during panic braking. The ABS controls the braking torque when the system identifies incipient wheel lock, since the driver will be unable to steer the vehicle as it continues to slide if the front wheels are locked, while the vehicle is prone to spin out of control when the rear wheels lock. Regenerative braking can be deployed to support hydraulic friction braking system during braking event to recuperate energy for future use and also during emergency situation such as to avoid wheel locking. Presently, only conservative strategies have been applied for the deployment of EM during braking, which is disabled if any risk of emergency situation emerges and the friction brakes are prioritised (Bayar et al. 2012, Crolla & Cao 2012).
Augment control
Published in Michael Wiklund, Kimmy Ansems, Rachel Aronchick, Cory Costantino, Alix Dorfman, Brenda van Geel, Jonathan Kendler, Valerie Ng, Ruben Post, Jon Tilliss, Designing for Safe Use, 2019
Michael Wiklund, Kimmy Ansems, Rachel Aronchick, Cory Costantino, Alix Dorfman, Brenda van Geel, Jonathan Kendler, Valerie Ng, Ruben Post, Jon Tilliss
Having proved its worth, ABS was required in new automobiles in the European Union countries starting in 2004.1 Although the United States had mandated ABS on trucks and buses in 1999,2 the US government was slow to adopt a mandate requiring ABS in cars. Finally, in 2011, cars sold in the US were required to incorporate an Electronic Stability Control (ESC) system, which uses automatic computer-controlled braking.3 Now, some cars can even detect hazards (e.g., an object in the road) and automatically apply the brakes to avoid a collision (see Principle 18 – Predict hazardous situations).
Chassis systems
Published in Tom Denton, Automobile Mechanical and Electrical Systems, 2018
If the ABS control unit detects that one or more wheels tend to lock, it intervenes within milliseconds by modulating the braking pressure at each individual wheel. In doing so, ABS prevents the wheels from locking and ensures safe braking because the vehicle remains steerable and stable. Generally, the stopping distance is also reduced.
A 3-phase combined wheel slip and acceleration threshold algorithm for anti-lock braking in heavy commercial road vehicles
Published in Vehicle System Dynamics, 2022
Akhil Challa, Karthik Ramakrushnan, Pavel Vijay Gaurkar, Shankar C. Subramanian, Gunasekaran Vivekanandan, Sriram Sivaram
ABS prevents wheel lock during emergency braking and braking on low friction surfaces. The algorithm used in ABS can be broadly classified into two categories. First, Model-Based Algorithms (MBAs) that are based typically on a first principles model of the system. Second, Rule-Based Algorithms (RBAs) that are typically empirical and based on a set of predefined thresholds for the controlled parameters. MBAs use mathematical models and require information pertaining to vehicle and tyre parameters, which are generally difficult to obtain on-line. Nonetheless, MBAs provide accurate tracking of the control variable owing to the availability of more information and consideration of comprehensive mathematical models. On the other hand, RBAs utilise set rules based on relevant variables for control action. Although RBAs may not capture the system dynamics to the level of detail as MBAs, they are simpler and tractable for implementation. RBAs are more prevalent in the commercial space due to their lower data requirement, while most laboratory research has focused on the utilisation of MBAs for WSR. In this work, a commercially viable RBA is being proposed.
Motorcycle active safety systems: Assessment of the function and applicability using a population-based crash data set
Published in Traffic Injury Prevention, 2019
Giovanni Savino, Marco Pierini, Michael Fitzharris
ABS prevents wheel lock under abrupt or intense braking and/or in conditions of low adherence between the tires and the road surface. MAEB scans the frontal surroundings of the host motorcycle and anticipates possible collisions with other vehicles or obstacles. As soon as the system identifies an inevitable collision event, a mild, autonomous deceleration of the host vehicle is deployed. At that point, if the rider has already started braking, the system deploys enhanced braking, assisting the rider in achieving the highest deceleration. Collision warning scans the frontal surroundings of the vehicle, issuing a warning to the rider when computed risk for collision exceeds a given threshold. Curve warning estimates the real-time state of the host PTW to compute the control actions required to safely maintain the vehicle on the road and in the correct lane. As soon as the gap between the computed maneuver and the actual maneuver performed by the rider exceeds given thresholds, warnings are issued to the rider. Curve assistance monitors the host vehicle dynamics and intervenes with a series of adjustments on the engine torque/brakes when a potential loss of control is detected, thus contributing to keeping the vehicle under control along the rider’s intended direction.
Motorcycle antilock braking systems and fatal crash rates: updated results
Published in Traffic Injury Prevention, 2022
Antilock braking systems (ABS) were developed to help vehicle operators avoid wheel lock during hard braking. ABS functions by monitoring wheel speed precisely during braking events and, when wheel lock is imminent, begins a cycle of reducing brake line pressure and increasing it again; this cycle repeats many times per second until the risk of wheel lock is no longer detected. Motorcycles equipped with ABS allow riders to confidently apply larger braking inputs in an emergency without fear of wheel lock. Some newer systems have been coupled with a lean angle sensor and complex algorithms to allow stronger braking inputs while cornering (Lich et al. 2016).