APS LABS (Advanced Power Systems Research Center)

Our mission is to promote & facilitate education and research in clean, efficient, and sustainable power and powertrain systems. The center was established in 2007 and in 2014 the 55,000 sq ft APSRC building located near the airport was denoted as a MTU core facility. Our new research contracts in FY2016 were over 2.5M. Our partners include automotive OEMs: GM, Ford, FCA, Toyota, Honda; Commercial OEMs: Cummins, Deere, Detroit, Isuzu, MHI; Suppliers: Delphi, Denso, Borg Warner, Hitachi; and DOE Labs: ANL, ORNL, PNNL, SNL, & INL. We have seven staff to assist in educational and R&D programs and facilities to support research at the fundamental to applied scale. The Mobile Lab provides outreach, education, and demonstration platform. We were recently awarded a 3.5M DOE ARPA-e program with GM to advance mobility and efficiency through connected an automated vehicle technologies. View more online at http://apslabs.me.mtu.edu.https://digitalcommons.mtu.edu/techtalks/1016/thumbnail.jp

DOE APRA-E NEXTCAR program on connected and automated vehicles in collaboration with GM

Within the $3.5M ARPA-e NEXTCAR program, Michigan Tech in collaboration with GM will development and demonstrate on a fleet of eight 2017 Chevrolet Volts and a mobile connected cloud computing center, a Vehicle Dynamics and Powertrain (VD&PT) model-based predictive controller (MPC) encompassing a real-time VD&PT dynamic model leveraging vehicle conductivity (V2X) with real-time traffic modeling and predictive speed horizons and eco-routing. The objective is to achieve a minimum of 20% reduction in energy consumption (electric + fuel) through the first ever real-time implementation and connection of route planning, powertrain energy management MPC algorithms. Connectivity data from vehicles, infrastructure, GPS, traffic and desired route planning combined with a dynamic model of the powertrain-vehicle system allows prediction of the vehicle’s future speed profile and enables forward looking optimization of powertrain mode selection, energy utilization from the battery and fuel source, and distribution of propulsive torque from the electric motors and/or internal combustion engine. Development and testing will be done at MCity and within a complete integrated vehicle and traffic simulation model.https://digitalcommons.mtu.edu/techtalks/1033/thumbnail.jp

Combustion knock detection and control through statistical characterization of knock levels

A method of statistically characterizing combustion knock events includes receiving signals from a sensing device such as an accelerometer, estimating at least one parameter of a probability distribution function based on the received signals, and calculating a value indicative of an r/h percentile based on the parameter to predict upcoming combustion knock events.https://digitalcommons.mtu.edu/patents/1030/thumbnail.jp

Review of sensing methodologies for estimation of combustion metrics

For reduction of engine-out emissions and improvement of fuel economy, closed-loop control of the combustion process has been explored and documented by many researchers. In the closed-loop control, the engine control parameters are optimized according to the estimated instantaneous combustion metrics provided by the combustion sensing process. Combustion sensing process is primarily composed of two aspects: combustion response signal acquisition and response signal processing. As a number of different signals have been employed as the response signal and the signal processing techniques can be different, this paper did a review work concerning the two aspects: combustion response signals and signal processing techniques. In-cylinder pressure signal was not investigated as one of the response signals in this paper since it has been studied and documented in many publications and also due to its high cost and inconvenience in the application

Spark ignited direct injection natural gas combustion in a heavy duty single cylinder test engine - nozzle included angle effects

The increased availability of natural gas (NG) in the United States (US) and its relatively low cost versus diesel fuel has increased interest in the conversion of medium duty (MD) and heavy duty (HD) engines to NG fueled combustion systems. The aim for development for these NG engines is to realize fuel cost savings and increase operating range while reduce harmful emissions and maintaining durability. Traditionally, port-fuel injection (PFI) or premixed NG spark-ignited (SI) combustion systems have been used for light duty LD, and MD engines with widespread use in the US and Europe [1]. However, this technology exhibits poor thermal efficiency and is load limited due to knock phenomenon that has prohibited its use for HD engines. Spark Ignited Direct Injection (SIDI) can be used to create a partially stratified combustion (PSC) mixture of NG and air during the compression stroke. PSC promises to deliver improved thermal efficiency by avoiding excessive premixing and extending the lean limits which helps to extend the knock and load limit. In this work, a CAT 3401 SCOTE single cylinder engine with 14:1 compression ratio (CR) was used to investigate SIDI NG combustion using an integrated spark injector-igniter. The injector nozzle included angle (NIA) was varied from 80 degrees to 150 degrees to determine the impact on fuel consumption, combustion stability, phasing, and emissions. Start of injection (SOI) and spark ignition (SPK) timings were determined from previous work for a near stoichiometric operation (AFR 16 to 20:1). The nozzle included angle of 100 degrees resulted in up to 43% indicated thermal efficiency across a part-load operating range 3 to 1 1 bar and provided the best trade-off between fuel economy, emissions and combustion stability. This work demonstrated the optimization potential of a 100 degree NIA for high thermal efficiency of a heavy duty engine over the low load operating conditions

Dual nature of hydrogen combustion knock

Combustion knock is abnormal combustion taking place in an internal combustion spark ignited engine. It might be particularly observed in the engine at the end of combustion when the air-fuel mixture residue can be self-ignited due to exceeding auto-ignition temperature of this mixture. However, while hydrogen is combusted the knock can also occur as a result of non-auto-ignited combustion events. Investigation on knock, presented in the manuscript, was conducted in a hydrogen fueled spark ignited single cylinder engine with variable compression ratio. To express in numbers intensity of the combustion knock the in-cylinder pressure pulsations were used as a credible metrics. On the basis of analysis of these pulsations the hydrogen knock was distinguished as light and heavy one depending on its origin. The light knock is generated by combustion instabilities, which are a source for generating pressure waves inside the engine cylinder. The heavy knock results from hydrogen auto-ignition at the end of combustion. Its intensity is several times higher in comparison to the light knock. These observations were additionally confirmed by analysis of heat release rate. Finally, the light and the heavy knock were characterized by average amplitude of the pulsations from the entire test series of hundreds and several thousands kPa, respectively. Copyright © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved

Alleviating the Magnetic Effects on Magnetometers Using Vehicle Kinematics for Yaw Estimation for Autonomous Ground Vehicles

Autonomous vehicle operation is dependent upon accurate position estimation and thus a major concern of implementing the autonomous navigation is obtaining robust and accurate data from sensors. This is especially true, in case of Inertial Measurement Unit (IMU) sensor data. The IMU consists of a 3-axis gyro, 3-axis accelerometer, and 3-axis magnetometer. The IMU provides vehicle orientation in 3D space in terms of yaw, roll and pitch. Out of which, yaw is a major parameter to control the ground vehicle\u27s lateral position during navigation. The accelerometer is responsible for attitude (roll-pitch) estimates and magnetometer is responsible for yaw estimates. However, the magnetometer is prone to environmental magnetic disturbances which induce errors in the measurement. The present work focuses on alleviating magnetic disturbances for ground vehicles by fusing the vehicle kinematics information with IMU senor in an Extended Kalman filter (EKF) with the vehicle orientation represented using Quaternions. In addition, the error in rate measurements from gyro sensor gets accumulated as the time progress which results in drift in rate measurements and thus affecting the vehicle orientation estimation. To resolve and account for the gyro drift, the EKF algorithm includes gyro bias terms in state vector, which augments the state vector with 4 Quaternions and 3 gyro bias vectors. The proposed modified EKF strategy has been experimentally tested and validated on 1/5th scale buggy type truck. The developed EKF, analysis and results are present which shows that, while the vehicle is affected by up to 1 ± 0.8 Norm of magnetic field and based on the curvature of the road it can reduce the RMS errors in yaw estimations from 3.4 to 0.5° in straight path and from 6.0 to 1.9° during tuning paths. Due to high accuracy in speed sensor and steering angle measurements, this fusion algorithm is robust and can make yaw estimations within ±1.5° heading error for about 30-meter distance

Optimization of performance and operational cost for a dual mode diesel-natural gas RCCI and diesel combustion engine

Diesel-NG fuel blends are increasingly being used in Reactivity Controlled Compression Ignition (RCCI) internal combustion engines due to high Brake Thermal Efficiency (BTE), low NOx and PM emissions. It also has few disadvantages such as high unburned Hydro Carbon (HC) and Carbon Monoxide (CO) emissions and relatively low Exhaust Gas Temperature (EGT). This study determines the optimum combustion mode between RCCI and Conventional Diesel Combustion (CDC) at different loads while meeting the Environmental Protection Agency (EPA) emission regulation. A Cost Function (CF) including Brake Specific Fuel Consumption (BSFC) and Brake Specific Urea Consumption (BSUC) is considered and minimized in this study. The optimization of input variables is done between 3 and 12 bar Indicated Mean Effective Pressure (IMEP) engine load. The study aims to calibrate the dual fuel diesel/NG RCCI engine to meet Tier 3 Bin 20 EPA standard, with or without after-treatment system, while minimizing the cost of operation. New parametric empirical models are developed and validated using experimental data from a light duty 1.9L inline 4 cylinder Compression Ignition (CI) engine as a function of independent input variables. All the experiments were conducted at Advanced Power System (APS) facility at Michigan Technological University. These models predict HC, CO, PM and NOx emissions, EGT and BSFC. These models are then used to predict new operating points to increase the population in the optimization process. The computed EGT is used to estimate the Selective Catalyst Reduction (SCR) and Diesel Oxidation Catalyst (DOC) efficiencies to assess the emission data with different input variables by considering the after-treatment system to see if they meet the tailpipe emission regulation. The optimization results recommend using Diesel/NG RCCI at 7 to 12 bar IMEP operating conditions and use CDC for below 7 bar IMEP operating condition

An experimental investigation into the effect of NO2 and temperature on the passive oxidation and active regeneration of particulate matter in a diesel particulate filter

The kinetics of particulate matter (PM) oxidation in a catalyzed particulate filter (CPF) under different exhaust temperature and NO2 conditions is presented along with a literature review of the related PM kinetic studies. The study was conducted with a 2013 heavy-duty engine that had NO2 levels significantly higher than engines that met the earlier 2007/2010 EPA standards, and the results show a significant increase in PM oxidation rate that is possible under normal vehicle operating conditions, to diminish the need to actively regenerate the DPF. The detailed procedure for determining the PM oxidized during the experiments is described. Two types of tests were conducted to determine the NO2 assisted as well as the thermal oxidation kinetics. Passive Oxidation (PO) tests were conducted for selected engine conditions that would cover the range of exhaust NO2 concentrations (137 to 1013 ppm tested) and temperatures (299 to 388 °C tested) during regular engine operation. Active regeneration (AR) tests were conducted to determine the thermal oxidation kinetics at exhaust temperatures from 498 to 575 °C which was induced by post fueling. The CPF was first loaded with PM to a target loading, and then the PM was oxidized under specific exhaust temperature and NO2/O2 concentration conditions. The data obtained in this study can also be used to calibrate a CPF model. The activation energies and pre-exponential factors for NO2 assisted and thermal oxidation were developed from the PO and AR data. It was also found that PM reactivity during PM loading was greater than for the passive oxidation tests