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Minimizing Disturbance Detection Time in Hydraulic Systems

General Motors LLC-Paul Otanez, Ramadityanand Bhogadi
  • Technical Paper
  • 2020-01-0263
To be published on 2020-04-14 by SAE International in United States
In a hydraulic system, parameter variation, contamination, and/or operating conditions can lead to instabilities in the pressure response. The resultant erratic pressure profile reduces performance and can lead to hardware damage. Specifically, in a transmission control system, the inability to track pressure commands can result in clutch or variator slip which can cause driveline disturbance and/or hardware damage. A variator is highly sensitive to slip and therefore, it is advantageous to identify such pressure events quickly and take remedial actions. The challenge is to detect the condition in the least amount of time while minimizing false alarms. A Neyman-Pearson and an energy detector (based on auto-correlation) are evaluated for the detection of pressure disturbances. The performance of the detectors is measured in terms of speed of detection and robustness to measurement noise. The implications in terms of computations and memory utilization of implementing the detectors in real-time embedded systems are also discussed. Both simulation and hardware examples are presented. The hardware experiment is performed in a hydraulic system with low damping composed of a solenoid…
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Bench-marking Computational Performance of Dynamic Programming For Speed Profiling and Fuel Efficiency of Autonomous-capable HEV

Ohio State University-Wilson Perez, Amit Ruhela, Punit Tulpule
  • Technical Paper
  • 2020-01-0968
To be published on 2020-04-14 by SAE International in United States
Dynamic programming has been used for optimal control of hybrid powertrain and vehicle speed optimization particularly in design phase for over a couple of decades. With the advent of autonomous and connected vehicle technologies, automotive industry is getting closer to implementing predictive optimal control strategies in real time applications. The biggest challenge in implementation of optimal controls is the limitation on hardware which includes processor speed, IO speed, and random access memory. Due to the use of autonomous features, modern vehicles are equipped with better onboard computational resources. In this paper we present a comparison between multiple hardware options for dynamic programming. The optimal control problem considered, is the optimization of travel time and fuel economy by tuning the torque split ratio and vehicle speed while maintaining charge sustaining operation. The system has two states - battery state of charge and vehicle speed, and two inputs namely, total torque and torque split ratio. First, we develop a Matlab® based program to solve the optimal control problem. The Matlab® code is optimized for performance and memory…
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Routing methods considering security and real-time of vehicle gateway system

FESCARO-Daehyun Kim
Infineon Technologies AG-Karel Heurtefeux
  • Technical Paper
  • 2020-01-1294
To be published on 2020-04-14 by SAE International in United States
Recently, vehicle networks have increased complexity due to the demand for autonomous driving or connected devices and require high bandwidth. And vehicle manufacturers have begun applying Ethernet protocols, a new network that can replace existing vehicle network protocols. However, it is difficult to replace the entire CAN protocols with Ethernet protocols completely due to safety and reliability issues. Therefore, the vehicle manufacturer introduced a vehicle gateway system. The system uses Ethernet for the external network and the CAN network for communication between internal controllers. The vehicle gateway system provides an interface for constantly connecting and exchanging vehicle data in a heterogeneous communication environment between the existing CAN network protocol and the external Ethernet protocol. Therefore, it is necessary to design the minimum delay time considering the real time. In addition, since there is a risk of hacking due to external communication connection, a security function to ensure the integrity of the message is essential. This paper introduces routing methods considering security and real time. In the case of security, the Cipher-based message authentication code (CMAC)…
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Experimental Investigation of Axial Cutting of AA6061 Extrusions under a Tension Deformation Mode

University of Windsor-Anthony Gudisey, William Altenhof, John Magliaro
  • Technical Paper
  • 2020-01-0206
To be published on 2020-04-14 by SAE International in United States
A plethora of applications in the transportation industry for both vehicular and roadside safety hardware, especially seatbelts, harnesses and restraints, rely on tensile loading to dissipate energy and minimize injury. There are disadvantages to the current state-of-the-art for these tensile energy absorbers, including erratic force-displacement responses and low tensile force efficiencies (TFE). Axial cutting was extensively demonstrated by researchers at the University of Windsor to maintain a stable reaction force, although exclusively under compressive loading. A novel apparatus was investigated in this study which utilized axial cutting under a tensile loading condition to absorb energy. A parametric scope was chosen to include circular AA6061 extrusions in both T4 and T6 temper conditions with an outer diameter of 63.5 mm and wall thickness of 3.18 mm. The experiments were performed quasi-statically utilizing a custom, hydraulically powered long stroke tension/compression testing machine with a maximum capacity of 300kN. Strain-gauge based load cells and non-contact displacement transducers were implemented to measure the cutting force and displacement response of the setup. The results demonstrated highly stable force responses, with…
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Joint Calibration of Dual LiDARs and Camera Using a Circular Chessboard

Tongji University-Zhenwen Deng, Lu Xiong, Dong Yin, Fengwu Shan
  • Technical Paper
  • 2020-01-0098
To be published on 2020-04-14 by SAE International in United States
Environmental perception is a crucial subsystem in autonomous vehicles. In order to build safe and efficient traffic transportation, several researches have been proposed to build accurate, robust and real-time perception systems. Camera and LiDAR are widely equipped on autonomous self-driving cars and developed with many algorithms in recent years. The fusion system of camera and LiDAR provides state-of the-art methods for environmental perception due to the defects of single vehicular sensor. Extrinsic parameter calibration is able to align the coordinate systems of sensors and has been drawing enormous attention. However, differ from spatial alignment of two sensors’ data, joint calibration of multi-sensors (more than two sensors) should balance the degree of alignment between each two sensors. In this paper, we assemble a test platform which is made up of dual LiDARs and one monocular camera and use the same sensing hardware architecture as intelligent sweeper designed by our laboratory. Meanwhile, we propose the related joint calibration method using a circular chessboard. The center of circular chessboard is respectively detected in camera image to get pixel…
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Finite Element Analysis Technique To Roll Crimp Solenoid’s Can

BorgWarner Inc.-Chandreshwar Rao
  • Technical Paper
  • 2020-01-0749
To be published on 2020-04-14 by SAE International in United States
Roll forming assemblies are generally neat and robust, but there are structural integrity risks involved too if the forming procedures and design features do not complement each other. Specifically, in solenoid valves, an imprecised roller crimping (or forming) adversely affect the desired magnetic performance of the valves. Furthermore, in-depth evaluations of the formed shape using hardware and lab testing are extremely challenging cost wise and time consuming as well. However, utilizing simulation technique such as finite element analysis (FEA) to understand the in-sights of roller formed assemblies of a solenoid valve (or other products) could be an effective way to minimize overall cost and time involved in the product development. Therefore, a three-dimensional non-linear FEA model of roller crimping simulation was established in ANSYS Workbench Mechanical, and the predicted results were correlated with real hardware data to prove the technique & process adopted. Then the design was improved computationally to eliminate the magnetic Core's flux-bridge distortion issue of a solenoid valve, and finally the design was validated through hardware testing.
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DC-link capacitor sizing in HEV/EV e-Drive Power Electronics System from Stability viewpoint

Ford Motor Company-Srikanthan Sridharan, Jun Kikuchi
  • Technical Paper
  • 2020-01-0468
To be published on 2020-04-14 by SAE International in United States
Selection of DC-link capacitance value in a HEV/EV e-Drive power electronics system depends on numerous factors including the capacitor’s required voltage/current ratings, power dissipation, thermal limitation, energy storage capacity, impact on system stability and so on. A significant challenge arises from capacitor selection based on DC-link stability due to the influence of multiple hardware parameters, control parameters, operating conditions and interaction effects among them. This paper introduces a methodology to determine the minimum required DC-link capacitance values that guarantee stable operation of the system in this multi-dimensional variable space. A broad landscape of the minimum capacitance values is also presented to provide valuable insights into the sensitivity of both hardware parameters and control parameters, on the overall system stability and understanding trade-offs and limits of these parameters. The target system example considered is a HEV e-Drive power electronics system consisting of one PWM DC/DC converter and two, three-phase PWM inverters, each inverter feeding an electrical machine. All the converters share the common dc-link at which the system stability is analyzed. Since the PWM converters are…
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Durability Study of a Light-Duty High Pressure Common Rail Fuel Injection System Using E10 Gasoline

Aramco Research Center-Tom Tzanetakis, Mark Sellnau, Vincent Costanzo, Michael Traver
Argonne National Laboratory-Aniket Tekawade, Brandon Sforzo, Christopher F. Powell
  • Technical Paper
  • 2020-01-0616
To be published on 2020-04-14 by SAE International in United States
In this study, a 500-hour test cycle was used to evaluate the durability of a prototype high pressure common rail injection system operating up to 1800 bar with E10 gasoline. Some aspects of the hardware were modified from their baseline design in order to accommodate an opposed-piston, two-stroke engine application and mitigate the impacts of exposure to gasoline. Overall system performance was maintained throughout testing as fueling rate and rail pressure targets were continuously achieved. Although evidence of vapor formation in the low-pressure part of the system was observed, there was no significant physical damage to the associated components. Injectors showed no deviation in their flow characteristics after exposure to gasoline and high resolution imaging of the nozzle tips and pilot valve assemblies did not indicate the presence of cavitation damage. The high pressure pump did not exhibit any performance degradation during gasoline testing and teardown analysis after 500 hours showed no evidence of cavitation erosion. Despite the lack of lubricity-improving additives in the gasoline, all other fuel-wetted components survived the test cycle without any…
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Engine Calibration Using Global Optimization Methods with Customization

Ford Motor Company-Ling Zhu, Yan Wang
Michigan State University-Anuj Pal, Guoming Zhu
  • Technical Paper
  • 2020-01-0270
To be published on 2020-04-14 by SAE International in United States
The automotive industry is subject to stringent regulations in emissions and growing customer demands for better fuel consumption and vehicle performance. Engine calibration, a process that optimizes engine performance by tuning engine controls (actuators), becomes challenging nowadays due to significant increase of complexity of modern engines. The traditional sweep-based engine calibration method is no longer sustainable. To tackle the challenge, this work considers two powerful global optimization methods: genetic algorithm (GA) and Bayesian optimization. In real engine testing platform, only the limited number of function evaluations (less than 400) is available. We customized GA to cope with limited resource. Another challenge of engine calibration is that, in real engine testing platform, some solutions cannot even run completely due to the engine hardware limitations. These solutions, called non-operational solutions, are part of infeasible solutions and do not have any information about either objectives or constraints. A constraint repair algorithm is applied to handle non-operational solutions. The experimental study on high-fidelity engine models demonstrated that both GA and Bayesian optimization effectively find solutions very close to global…
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A cybersecurity testbed for connected and autonomous vehicles

Ohio State University-Matthew Appel, Pradeep Sharma Oruganti, Qadeer Ahmed, Jaxon Wilkerson, Rubanraj Sekar
  • Technical Paper
  • 2020-01-1291
To be published on 2020-04-14 by SAE International in United States
Connectivity and autonomy in vehicles promise improved efficiency, safety and comfort. The increasing use of embedded systems and the cyber element bring with them many challenges regarding cyberattacks which can seriously compromise driver and passenger safety. Beyond penetration testing, assessment of the security vulnerabilities of a component must be done through the design phase of its life cycle. This paper describes the development of a benchtop testbed which allows for the safety and security evaluations of components with all capabilities from Model-in-loop to Software-in-loop to Hardware-in-loop testing. Environment simulation is obtained using the AV simulator, CARLA which provides realistic scenarios and sensor information such as Radar, Lidar etc. MATLAB runs the vehicle, powertrain and control models of the vehicle allowing for the implementation and testing of realistic models. Real-time simulation and connectivity with external components is obtained through the use of a Speedgoat real-time machine. A fluid integration between the multiple software parts are realized using Robotic-Operating-System (ROS). Communication with external hardware can be achieved through different network protocols such as CAN, LIN, SAE J1939…