Showing 11 results for Braking
E. Esmailzadeh, A. Goodarzii, M. Behmadi,
Volume 1, Issue 1 (1-2011)
Abstract
Improvement in braking performance and vehicle stability can be achieved through the use of braking systems whose brake force distribution is variable. Electronic braking force distribution has an important and serious role in the vehicle stopping distance and stability. In this paper a new approach will be presented to achieve the braking force distribution strategy for articulated vehicles. For this purpose, the mathematical optimization process has been implemented. This strategy, defined as an innovative braking force distribution strategy, is based on the wheel slips. The simulation results illustrate proposed strategy can significantly improve the vehicle stability in curved braking for different levels of vehicle deceleration
M. M. Tehrani, M. R. Hairi-Yazdi, Ba. Haghpanah-Jahromi, V. Esfahanian, M. Amiri, A. R. Jafari,
Volume 1, Issue 2 (6-2011)
Abstract
In this paper, an adaptive rule based controller for an anti-lock regenerative braking system (ARBS) of a series hybrid electric bus (SHEB) has been proposed. The proposed controller integrates the regenerative braking and wheel anti-lock functions by controlling the electric motor of the hybrid vehicle, without using any conventional mechanical anti-lock braking system. The performance of the proposed system is evaluated by a comprehensive vehicle dynamics model in MATLAB/Simulink. Using the designed ARBS, the braking and regenerative performances of SHEB have significantly improved in slippery roads while the slip ratios are kept between 0.15 and 0.20.
M. A. Saeedi, R. Kazemi,
Volume 3, Issue 1 (3-2013)
Abstract
In this study, stability control of a three-wheeled vehicle with two wheels on the front axle, a three-wheeled
vehicle with two wheels on the rear axle, and a standard four-wheeled vehicle are compared. For vehicle
dynamics control systems, the direct yaw moment control is considered as a suitable way of controlling the
lateral motion of a vehicle during a severe driving maneuver. In accordance to the present available
technology, the performance of vehicle dynamics control actuation systems is based on the individual
control of each wheel braking force known as the differential braking. Also, in order to design the vehicle
dynamics control system the linear optimal control theory is used. Then, to investigate the effectiveness of
the proposed linear optimal control system, computer simulations are carried out by using nonlinear twelvedegree-
of-freedom models for three-wheeled cars and a fourteen-degree-of-freedom model for a fourwheeled
car. Simulation results of lane change and J-turn maneuvers are shown with and without control
system. It is shown that for lateral stability, the three wheeled vehicle with single front wheel is more stable
than the four wheeled vehicle, which is in turn more stable than the three wheeled vehicle with single rear
wheel. Considering turning radius which is a kinematic property shows that the front single three-wheeled
car is more under steer than the other cars.
Gh.h Payeganeh, M. Esfahanian, S. Pakdel Bonab,
Volume 4, Issue 2 (6-2014)
Abstract
In the present paper, the idea of braking energy regeneration and reusing that energy during acceleration for a refuse truck is comprehended. According to their driving cycle, the refuse trucks have a good potential for braking energy regeneration. On the other hand, hydraulic hybrid is a powertrain with high power density which is appropriate for energy regeneration. In the primary stage of this issue, the hydraulic hybrid propulsion system is designed with intention of regenerating the maximum possible kinetic energy during the refuse truck braking mode. At this stage, a non-fuzzy rule-based control strategy is applied to manage the energy flow in the hybrid powertrain. After that, the powertrain of the Axor 1828 truck and the elements of the hydraulic powertrain are modeled in MATLAB/Simulink. The modeling is performed considering the efficiencies of the powertrain elements. In the last part of the paper, a fuzzy control strategy is designed and modeled to improve the fuel consumption of the truck with hybrid powertrain. In order to see the usefulness of the designed hybrid powertrain, several simulations are organized on the vehicle model in Simulink. The driving cycle for refuse truck in Tehran is used for performing the simulations. The results state indicated that using the hydraulic hybrid powertrain decreased the fuel consumption of the refuse truck by 7 percent. In addition, this amount of reduction was improved by implementing the fuzzy control strategy. The decrease in fuel consumption was due to the regenerating of the braking energy up to 50 percent.
Prof. Dr. Ataur Rahman, Mr Mohammad Amysar,
Volume 8, Issue 2 (6-2018)
Abstract
ABSTRACT: Deceleration or stopping the vehicle without any diving and lateral acceleration is essential to develop an effective braking system. The hydraulic braking system with intelligent braking called Antilock Braking system (ABS) and Electronic Stability Control (ESC) has been introduced. However, due to the insufficient human effort, the ABS and ESC to some extent, not function well. This has been emphasised to develop a DC motor assist hydraulic braking system by associating the wheel speed and engine fuel flow sensor to stop the vehicle in required braking distance without any diving and lateral movement. This study investigates theoretically by Solid work simulation model and experimentally by product development. The simulation model has shown that a full load passenger car needs 15.7Mpa of braking pressure to stop 50km/h vehicle in 10m. The experimental results of the model show that the pressure develops when the pedal fully applied without and with aids of the DC motor is 910 kPa and 1130 kPa respectively, which contribute to 23.3% of pressure increase.
KEYWORDS: DC motor assist hydraulic braking system; Digital Control System; Braking efficiency.
Mohsen Esfahanian, Mohammad Saadat, Parisa Karami,
Volume 8, Issue 3 (9-2018)
Abstract
Hybrid electric vehicles employ a hydraulic braking system and a regenerative braking system together to provide enhanced braking performance and energy regeneration. In this paper an integrated braking system is proposed for an electric hybrid vehicle that include a hydraulic braking system and a regenerative braking system which is functionally connected to an electric traction motor. In the proposed system, four independent anti-lock fuzzy controllers are developed to adjust the hydraulic braking torque in front and rear wheels. Also, an antiskid controller is applied to adjust the regenerative braking torque dynamically. A supervisory controller, is responsible for the management of this system. The proposed integrated braking system is simulated in different driving cycles. Fuzzy rules and membership functions are optimized considering the objective functions as SoC and slip coefficient in various road conditions. The simulation results show that the fuel consumption and the energy loss in the braking is reduced. In the other hand, this energy is regenerated and stored in the batteries, especially in the urban cycles with high start/stop frequency. The slip ratio remains close to the desired value and the slip will not occur in the whole driving cycle. Therefore, the proposed integrated braking system can be considered as a safe, anti-lock and regenerative braking system.
Mr. Sohrab Pakdel Bonab, Dr. Afshin Kazerooni, Dr. Gholamhassan Payganeh, Dr. Mohsen Esfahanian,
Volume 10, Issue 1 (3-2020)
Abstract
Driving cycle is used to assess fuel consumption, pollutant emissions and performance of the vehicle. The aim of this paper is to extract the driving cycle for refuse collection truck and estimate its braking energy. For this purpose, after selecting the target truck and geographic area, the equipment needed to measure the required variables were prepared and mounted on the truck. Then, the actual data were collected from the performance of the target Truck while performing its mission. Since the amount of braking energy depends on the speed, truck mass and road grade, the speed of the vehicle is measured simultaneously with the truck mass and road grade. The collected data are then processed and subdivided into micro-trips. The micro-trips are clustered according to the number of state spaces using the K-Means algorithm. Next, the representative micro trips are selected from within the clusters and the final driving cycle is generated. The representative driving cycle shows that the truck speed is zero at 47% of the working time. Finally, the amount of braking power and accumulative braking energy in the driving cycle is calculated.
Abbas Harifi, Farzan Rashidi, Fardad Vakilipoor Takaloo ,
Volume 10, Issue 1 (3-2020)
Abstract
The control of Antilock Braking Systems (ABS) is a difficult problem, because of their nonlinearities and uncertainties appearing in their dynamics and parameters. To overcome these issues, this paper proposes a new adaptive controller for the next generation of ABS. After considering a complex vehicle dynamic, a triple adaptive fuzzy control system is presented. Important parameters of the vehicle dynamic include two separated brake torques for front ands rear wheels, as well as longitudinal weight transfer which is caused by the acceleration or deceleration. Because of the nonlinearity of the vehicle dynamic model, three fuzzy-estimators have been suggested to eliminate nonlinear terms of the front and rear wheels’ dynamic. Since the vehicle model parameters change due to variations of road conditions, an adaptive law of the controller is derived based on Lyapunov theory to adapt the fuzzy-estimators and stabilize the entire system. The performance of the proposed controller is evaluated by some simulations on the ABS system. The results demonstrate the effectiveness of the proposed method for ABS under different road conditions.
Mahdi Ajami, Hossein Jannat, Masoud Masih-Tehrani,
Volume 10, Issue 4 (12-2020)
Abstract
Braking test is one of the most important tests of a mechanized technical inspection line. In this study, the effect of tire pressure changes on the accuracy of the braking test results is investigated at technical inspection centers. This study is conducted in three stages. In the first step, the braking efficiency at different tire pressures is examined using a roller brake tester. In the second step, the tests at different pressures and velocities on the road are done. These tests are carried out in terms of stopping distance, to ensure the accuracy and reliability of the first step test results. The results of the first and second steps showed that the effect of tire pressure changes on the braking efficiency is significant. In the third step, the braking test results of a thousand vehicles that received technical inspection certificate are studied. Analysis of these results, considering the results of the first and second steps cleared that about 16% of vehicles that received technical inspection certificate have lower braking efficiency than the minimum acceptable efficiency. The obtained results specified the necessity of adjusting the pressure of tires before the braking test at vehicle technical inspection centers in Iran.
Dr. Silas Okuma, Mr. Chidi Ihe,
Volume 12, Issue 4 (12-2022)
Abstract
Go-karts are popular sport mini-car in western countries, and there are gaining prominence in developing countries such as Nigeria. Its performance is determined by the chassis design and the braking system is its lifeline. Because of the lack of a suspension system and differentials, a good chassis must be able to bend and twist.
This Go-kart is powered by a Yamaha Vino Automatic Petrol 2-stroke Engine that generates approximately 4.1kw of power at 9018rpm. It boasts slick tyres for increased grip and a hydraulic disc brake for smooth and effective braking in both wet and dry conditions. The focus of this paper is on the braking system and material characterization of its structural members
Simulation static study with Autodesk Inventor yielded the following results: Mass Density 281.550 lbmass/ft3 Yield Strength 40.000 ksi Ultimate Tensile Strength 50.000ksi. Design calculations were performed, and the best possible result was obtained. Ergonomics, safety, cost of manufacturing, and reliability are all considered.
Morteza Mollajafari, Javad Marzbanrad, Pooriya Sanaei,
Volume 12, Issue 4 (12-2022)
Abstract
The braking system has always been considered one of the most significant vehicle subsystems since it plays a key role in safety issues. To design such a complex system, modeling can be a helpful tool for designers to save time and costs. In this paper, the hydraulic braking system of a B-Class vehicle was modeled by simulating the relationship between brake components such as pedals, boosters, main cylinders, and wheel cylinders, with the vehicle dynamics by using the existing models of the tire and their dynamic relationships. The performed modeling was compared with the results of a concerning vehicle's direct movement. The results of this comparison showed that our modeling is very close to the experimental data. The braking distance parameter was selected to examine the effects of each braking component on the vehicle dynamics. The results of investigating the effect of different parameters of the braking system on the dynamic behavior of the vehicle indicated that the main cylinder diameter, the diameter of the front and rear wheels’ brake cylinders, the effective diameter of the front disk, and the diameter of the rear drum are the most effective design parameters in vehicle's braking system and optimal results are obtained by applying changes to these parameters.
