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Technical Paper

Trajectory-Tracking Control for Autonomous Driving Considering Its Stability with ESP

2018-08-07
2018-01-1639
With rapid increase of vehicles on the road, safety concerns have become increasingly prominent. Since the leading cause of many traffic accidents is known to be by human drivers, developing autonomous vehicles is considered to be an effective approach to solve the problems above. Although trajectory tracking plays one of the most important roles on autonomous driving, handling the coupling between trajectory-tracking control and ESP under certain driving scenarios remains to be challenging. This paper focuses on trajectory-tracking control considering the role of ESP. A vehicle model is developed with two degrees of freedom, including vehicle lateral, and yaw motions. Based on the proposed model, the vehicle trajectory is separated into both longitudinal and lateral motion. The coupling effect of the vehicle and ESP is analyzed in the paper. The lateral trajectory-tracking algorithm is developed based on the preview follower theory.
Technical Paper

Rapid Spherical Near-Field Antenna Measurements for Vehicle Applications

2005-04-11
2005-01-0569
As more wireless services such as satellite radio (SDARS), navigation systems, OnStar, and mobile telephones are installed on GM vehicles, there is a need to make quick and accurate vehicle antenna pattern measurements. The interaction between vehicle and antenna must be included to ensure accurate vehicle antenna measurements. This implies that the size of the effective antenna should include both the antenna and vehicle interaction dimensions. For the frequency range of 500 MHz to 6 GHz, one solution is to use a spherical near-field system. The Satimo rapid probe array technology was selected to develop a vehicle antenna test system (ATS), which minimizes test time and maintains data accuracy. The ATS was designed to operate inside of an existing GM electromagnetic compatibility (EMC) anechoic chamber equipped with a nine-meter turntable.
Technical Paper

Powertrain Mounting Robust Evaluation Methodology Utilizing Minimal Hardware Resources

2017-06-05
2017-01-1823
Powertrain mounting systems design and development involves creating and optimizing a solution using specific mount rates and evaluation over multiple operating conditions. These mount rates become the recommended “nominal” rates in the specifications. The powertrain mounts typically contain natural materials. These properties have variation, resulting in a tolerance around the nominal specification and lead to differences in noise and vibration performance. A powertrain mounting system that is robust to this variation is desired. The design and development process requires evaluation of these mounts, within tolerance, to ensure that the noise and vibration performance is consistently met. During the hardware development of the powertrain mounting system, a library of mounts that include the range of production variation is studied. However, this is time consuming.
Journal Article

Methods and Tools for Calculating the Flexibility of Automotive HW/SW Architectures

2012-04-16
2012-01-0005
To cope with the increasing number of advanced features (e.g., smart-phone integration and side-blind zone alert.) being deployed in vehicles, automotive manufacturers are designing flexible hardware architectures which can accommodate increasing feature content with as fewer as possible hardware changes so as to keep future costs down. In this paper, we propose a formal and quantitative definition of flexibility, a related methodology and a tool flow aimed at maximizing the flexibility of an automotive hardware architecture with respect to the features that are of greater importance to the designer. We define flexibility as the ability of an architecture to accommodate future changes in features with no changes in hardware (no addition/replacement of processors, buses, or memories). We utilize an optimization framework based on mixed integer linear programming (MILP) which computes the flexibility of the architecture while guaranteeing performance and safety requirements.
Technical Paper

Development of an Electronically-Controlled, Limited-Slip Differential (eLSD) for FWD Applications

2007-04-16
2007-01-0925
Limited-slip differentials improve traction and handling when compared to open differentials, but offer no active modulation and can compromise typical driving. A number of passive control systems exist that attempt to reduce this compromise. Electronically controlled limited-slip differentials (eLSD) are being introduced that allow active control of the differential in all driving situations and can be operated as an open differential, a fully locked differential, or at any point between these extremes. Such an eLSD system was implemented in two General Motors front wheel drive cars-one on an automatic transmission and applied by the transmission pump, the other on a manual transmission and applied by an external pump. This eLSD system contains a multi-plate wet clutch connected to the differential carrier and right side half-shaft of an all wheel drive capable transmission.
Technical Paper

Brake Response Time Measurement for a HIL Vehicle Dynamics Simulator

2010-04-12
2010-01-0079
Vehicle dynamics simulation with Hardware In the Loop (HIL) has been demonstrated to reduce development and validation time for dynamic control systems. For dynamic control systems such as Anti-lock Braking System (ABS) and Electronic Stability Control (ESC), an accurate vehicle dynamics performance simulation system requires the Electronic Brake Control Module (EBCM) coupled with the vehicles brake system hardware. This kind of HIL simulation-specific software tool can further increase efficiency by means of automation and optimization of the development and validation process. This paper presents a method for HIL vehicle dynamics simulator optimization through Brake Response Time (BRT) correlation. The paper discusses the differences between the physical vehicle and the HIL vehicle dynamics simulator. The differences between the physical and virtual systems are used as factors in the development of a Design Of Experiment (DOE) quantifying HIL simulator performance.
Technical Paper

An Analytical Control Systems Approach to Steering Shudder

1995-05-01
951254
Historically, power steering shudder, a vibration which occurs while steering a vehicle at low speeds, has been approached with systematic component-swapping experiments. This approach was time consuming and did not necessarily yield satisfactory results. In this paper it is shown that steering shudder can be analytically approached as a control system with a closed-loop limit cycle caused by the interaction of the chassis and the steering system. This approach provides a metric for determining a vehicle's propensity to shudder and allows quick predictions of the results of changing components. The approach is model-based, and incorporates chassis and hydraulic system components. Results obtained from the control systems analysis have been validated by a vehicle study, which showed a strong correlation between subjective evaluations and the stability metric provided by the analysis.
Technical Paper

Active Fuel Management™ Technology: Hardware Development on a 2007 GM 3.9L V-6 OHV SI Engine

2007-04-16
2007-01-1292
In the North American automotive market, cylinder deactivation by means of engine valve deactivation is becoming a significant enabler in reducing the Brake Specific Fuel Consumption (BSFC) of large displacement engines. This allows for the continued market competitiveness of large displacement spark ignition (SI) engines that provide exceptional performance with reduced fuel consumption. As an alternative to a major engine redesign, the Active Fuel Management™ (AFM™) system is a lower cost and effective technology that provides improved fuel economy during part-load conditions. Cylinder deactivation is made possible by utilizing innovative new base engine hardware in conjunction with an advanced control system. In the GM 3.9L V-6 Over Head Valve (OHV) engine, the standard hydraulic roller lifters on the engine's right bank are replaced with deactivating hydraulic roller lifters and a manifold assembly of oil control solenoids.
Technical Paper

Achievements and Exploitation of the AUTOSAR Development Partnership

2006-10-16
2006-21-0019
Reductions of hardware costs as well as implementations of new innovative functions are the main drivers of today's automotive electronics. Indeed more and more resources are spent on adapting existing solutions to different environments. At the same time, due to the increasing number of networked components, a level of complexity has been reached which is difficult to handle using traditional development processes. The automotive industry addresses this problem through a paradigm shift from a hardware-, component-driven to a requirement- and function-driven development process, and a stringent standardization of infrastructure elements. One central standardization initiative is the AUTomotive Open System ARchitecture (AUTOSAR). AUTOSAR was founded in 2003 by major OEMs and Tier1 suppliers and now includes a large number of automotive, electronics, semiconductor, hard- and software companies.
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