Germann S.,Horiba Instruments Inc.
SAE Technical Papers | Year: 2011
In the past, static brake tests involved either pneumatic or hydraulic lever arm concepts, which allowed high torque loads on main and parking brakes in standstill. However modern and realistic test procedures like the analysis in pull away scenarios (stick - slip effect) or the so-called creep and groan test require a full rotational degree of freedom for the brake in the test cell. In order to provide this functionality an additional motor and gearbox is usually added to the brake test cell. Providing high gear ratio, this motor allows high torque at low speed for multiple rotations of the brake. Because of the speed limit, this motor-gearbox combination cannot be used for regular test procedures. Another limiting disadvantage of this concept is the usage of a coupling device to add or remove this motor from the shaft. This technique does not allow realistic test profiles. First, because the coupling/decoupling process requires some time in which the brake may cool down and second because the coupling process creates torque traces on the brake. A solution that uses the main drive also for static brake testing would overcome these disadvantages. Although the obstacle lays in the fact that DC motors cannot hold high torque rates at standstill for a longer period of time. The concept of variable frequency drives together with asynchronous motors offer now a new technique. This paper describes the usage of these motor drive concepts for static brake testing and the problem of low speed measurement at or near standstill as well as the related disharmonies in torque and speed. Copyright © 2011 SAE International. Source
Bougher T.,Southwest Research Institute |
Khalek I.A.,Southwest Research Institute |
Trevitz S.,Volvo |
Akard M.,Horiba Instruments Inc.
SAE Technical Papers | Year: 2010
This paper summarizes the validation testing of the Horiba Instruments OBS-2200 gaseous portable emissions measurement system (PEMS) for in-use compliance testing per Title 40 of the Code of Federal Regulations (CFR) Part 1065.920 ($1065.920). The qualification process included analyzer verifications as well as engine testing on a model-year 2007 heavy-duty diesel engine produced by Volvo Powertrain. The measurements of brake-specific emissions with the OBS-2200 were compared to those of a CFR Part 1065-compliant CVS test cell over a series of not-to-exceed (NTE) events. The OBS-2200 passed all linearity verifications and analyzer checks required of PEMS. Engine test validation was achieved for all three regulated gaseous emissions (CO, NMHC, and NO X) per 40 CFR Part1065.920(b)(5)(i), which requires a minimum of 91 percent of the measurement allowance adjusted deltas to be less than or equal to zero. The PEMS correlated much better to the laboratory than was necessary to satisfy the verification criteria with 100 percent of the measurements passing for all constituents. The average brake-specific CO 2 and NO X values both fell within five percent of the laboratory values, while the CO and NMHC levels were both below three percent of the 2007 standard as measured by both systems. Several different time alignment techniques for adjusting the alignment of the engine electronic control module (ECM) parameters, gas concentrations, and exhaust flow signals are discussed as well as the CO 2 and NO X measurement sensitivity to misalignment. A one second difference in time alignment between gas concentration and exhaust flow was found to change the brake specific emissions by as much as ten percent for a single NTE event and five percent for an average of all NTE events. Copyright © 2010 SAE International. Source
Gilmore A.M.,Horiba Instruments Inc.
Methods in Molecular Biology | Year: 2014
Contemporary spectrofluorimeters comprise exciting light sources, excitation and emission monochromators, and detectors that without correction yield data not conforming to an ideal spectral response. The correction of the spectral properties of the exciting and emission light paths first requires calibration of the wavelength and spectral accuracy. The exciting beam path can be corrected up to the sample position using a spectrally corrected reference detection system. The corrected reference response accounts for both the spectral intensity and drift of the exciting light source relative to emission and/or transmission detector responses. The emission detection path must also be corrected for the combined spectral bias of the sample compartment optics, emission monochromator, and detector. There are several crucial issues associated with both excitation and emission correction including the requirement to account for spectral band-pass and resolution, optical band-pass or neutral density filters, and the position and direction of polarizing elements in the light paths. In addition, secondary correction factors are described including (1) subtraction of the solvent's fluorescence background, (2) removal of Rayleigh and Raman scattering lines, as well as (3) correcting for sample concentration-dependent inner-filter effects. The importance of the National Institute of Standards and Technology (NIST) traceable calibration and correction protocols is explained in light of valid intra-and interlaboratory studies and effective spectral qualitative and quantitative analyses including multivariate spectral modeling. © 2014 Springer Science+Business Media, LLC. Source
Newberger N.,Horiba Instruments Inc.
26th Electric Vehicle Symposium 2012, EVS 2012 | Year: 2012
The hybrid electric vehicle (HEV) is becoming a sustainable vehicle architecture with the US government pouring 14.4 bilUon' into stimulus projects that support drivetrains of new vehicles that are series hybrid, parallel hybrid, or completely battery powered (BEV). Both the series hybrid and BEV have 100% of propulsion energy coming from electricity. The series hybrid uses an internal combustion engine (ICE) to power a generator that produces electricity. The parallel hybrid powers the vehicle by a mechanical combination of electric motors and ICE. In all cases, the drivetrain needs an electric motor, a traction battery and an auxihary method of obtaining electricity. These auxiliary power units (APU) are typically a downsized, highly efficient ICE or fuel cell for a zero emissions alternative. Horiba's Virtual Engine (VE) and Virtual Battery (VB) are HIL^ products that allow electric motor based drivetrain development without waiting for the new battery pack and ICE to become available. Relevant product features for HEV development are discussed in terms of form function, and verification with data.2 HIL commonly referred to as hardware in the loop where something physical is used to create power, or run programs, or create a response but inputs and outputs are simulated from a mathematical model of their real end use condition. Source
Horiba Instruments Inc. | Date: 2010-12-23
A dynamometer may be configured to simulate the rotating inertial characteristics of a wheel-tire assembly slipping relative to a road surface and having rotating inertial characteristics different than the rotating inertial characteristics of the wheel-tire assembly being simulated.