Static WCET Analysis of Real-Time Task-Oriented Code in Vehicle Control Systems

At present, the commercially available tire monitoring systems are not equipped to sense and transmit high speed dynamic variables used for real-time active safety control systems. Hence, today’s vehicle control systems are limited by the lack of knowledge of critical tire-road states (i.e. the kinematic conditions of the tire to its dynamic properties). From aforementioned discussion, it is clear that some method of estimating tire-road contact parameters would be greatly desirable. Existing tire-road friction estimation approaches often require certain levels of vehicle longitudinal and/or lateral motion to satisfy the persistence of excitation condition for reliable estimations. Such excitations may undesirably interfere with vehicle motion controls. This paper presents a novel development and implementation of a real-time tire-road contact parameter estimation methodology using acceleration signals from a smart tire. The proposed method characterizes the terrain using the measured frequency response of the tire vibrations and provides the capability to estimate the tire road friction coefficient under extremely lower levels of force utilization. Under higher levels of force excitation (high slip conditions), the increased vibration levels due to the stick/slip phenomenon linked to the tread block vibration modes make the proposed tire vibrations based method unsuitable. Therefore for high slip conditions, a tire-road friction model-based parameter estimation approach is proposed. Hence an integrated approach using the smart tire based friction estimator and the model based estimator gives us the capability to reliably estimate friction for a wider range of excitations. Considering the strong interdependence between the operating road surface condition and the instantaneous forces and moments generated; this real time estimate of the tire-road friction coefficient is expected to play a pivotal role in improving the performance of a number of vehicle control systems. In particular, this paper focuses on the possibility of enhancing the performance of collision mitigation braking systems.

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Network Traffic Lights with Telemetry and Wireless Connectivity Perimeter

MATEC Web of Conferences ◽

10.1051/matecconf/201925605002 ◽

2019 ◽

Vol 256 ◽

pp. 05002

Author(s):

España Víctor ◽

Chuchon Eddy ◽

Caytuiro David ◽

Iván Advincula ◽

Mario Chauca

Keyword(s):

Control Systems ◽

Real Time ◽

Network Traffic ◽

Traffic Congestion ◽

Vehicle Control ◽

Traffic Light ◽

Traffic Lights ◽

The Creation ◽

Research Document ◽

Smart Traffic

The following research document seeks to show an alternative to vehicle control systems using existing technologies to develop a system that is efficient and reliable. The creation and operation of a traffic light network will be presented, which will be located in an area where there is traffic congestion. The following network will reorganize, optimize, and measure the vehicular flow in real time. In some countries, intelligent traffic lights have been implemented, with which they have obtained satisfactory benefits by improving the vehicular flow of the places where these systems are located; for this reason we consider it necessary to use smart traffic lights in our country.

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A real-time task-oriented scheduling algorithm for distributed multi-robot systems

IEEE International Conference on Robotics and Automation, 2004. Proceedings. ICRA '04. 2004 ◽

10.1109/robot.2004.1307447 ◽

2004 ◽

Cited By ~ 5

Author(s):

P. Yuan ◽

M. Moallem ◽

R.V. Patel

Keyword(s):

Real Time ◽

Scheduling Algorithm ◽

Time Task ◽

Robot Systems ◽

Task Oriented ◽

Multi Robot

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Real-Time Vehicle Dynamics Parameter Estimation

Dynamic Systems and Control, Parts A and B ◽

10.1115/imece2005-79224 ◽

2005 ◽

Cited By ~ 1

Author(s):

Kwang-Keun Shin

Keyword(s):

Parameter Estimation ◽

Control Systems ◽

Real Time ◽

Vehicle Dynamics ◽

Estimation Method ◽

Vehicle Control ◽

Simulation Software ◽

Tire Pressure ◽

Vehicle Simulation ◽

The Stability

Vehicle dynamics parameters such as understeer coefficient are very important factors to determine the stability and dynamic handling behavior of a vehicle. These parameters vary during the lifetime of a vehicle according to different loading, tire pressure/wear or vehicle-to-vehicle variations of suspension characteristics, etc. The parameter deviations from nominal values may cause performance degradation of chassis/vehicle control systems, which is often designed based on the nominal values. Therefore, if the vehicle dynamics parameters can be estimated and monitored in real-time, the performance of chassis/vehicle control systems could be further enhanced. This paper presents a real-time vehicle dynamics parameter estimation method that estimates vehicle understeer coefficient and front/rear cornering compliances. The algorithm is implemented using Simulink, and analyzed, and validated using VehSim, which is a PC windows-based vehicle simulation software for vehicle dynamics controls and integration. The simulation results show that the developed algorithm is well capable of estimating vehicle dynamics parameters of VehSim, and, therefore, is highly feasible for in-vehicle applications.

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