What is a Normal to Moderate Vehicle Deceleration?

Topics related to Vehicle Specifications, Vehicle Acceleration Tests, Vehicle Braking Tests
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MSI
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What is a Normal to Moderate Vehicle Deceleration?

Post by MSI »

Q: I’m looking for a study or studies that reference normal to moderate decel rates for light vehicles.


A: The following are some reference papers posted up to a private forum so i post here since all publically available documents. I include some figures and direct links for some references i have in library.
  • "Normal Pedal Activation in Real World Situations" - Weaver, SAE 2011-01-0551
    ABSTRACT
    • This study reports pedal activation forces and typical acceleration and deceleration rates during everyday driving activities. Twenty subjects of varying ages, height and weight participated in the study. Each subject was asked to drive a four-door sedan along 2.3 miles of roadway in DuPage County, Illinois. Vehicle speed, acceleration, and position were measured using a global positioning system that was synchronized with force data collected from load cells rigidly mounted on the vehicle's accelerator and brake pedals. Pedal forces and vehicle behavior were measured during common driving tasks such as, shifting the transmission into reverse, backing out of a parking spot, and, making a right hand turn from a stop sign. Our data suggests that simple vehicle dynamic tasks produced in experimental settings may not reliably reproduce vehicle and occupant behavior. The pattern of brake pedal force when decelerating to a stop sign was usually not constant; but instead, displayed a dip, indicating that occupants were modulating their brake application. Also, the acceleration and deceleration rates recorded in this study were within the lower range of standard passenger acceleration rates used in accident reconstruction. The results from this study add to the body of literature on normal acceleration rates of passenger car during typical driving maneuvers.
  • "Characteristic Vehicular Deceleration for Known Hazards" - Roenitz, SAE 1999-01-0098
    ABSTRACT
    • This paper quantifies the deceleration of motor vehicles as they were routinely stopped for an expected hazard in a real world environment. It was observed that the deceleration rate varied non-linearly, with a peak value of about 0.25g as the vehicle decelerated through the speed range of 20 to 30 km/h. This deceleration pattern was common to all evaluated categories of passenger vehicles.
      A mathematical model was developed to define the deceleration profile; enhancement of this model yielded predictive relations for the velocity, position and remaining braking time of decelerating passenger vehicles
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  • A study on driver behaviour during braking on open road. Kassaagi et al, Paper 340, 18th ESV Conference
    • Thanks to new advances in automotive technology, active safety systems (emergency brake assistor EBA, ESP...) are designed to avoid accidents or reduce their severity. Their triggering are often based on drivers’ behavior. Their efficiency depends, on the experimental or real data representativeness, and on the triggering criteria definition. According to the literature, a few experiments have been carried out with “normal”drivers in “natural” or emergency situations in order to search for variables correlated to the intention and the needs of drivers. These data are necessary to define a “borderline” between emergency and natural driving to ensure that the system will be activated only if drivers need it.An experiment was conducted on open road. A hundred volunteers drove approximately 100 km. Traffic parameters and subjects’ actions on the car’s controls were recorded and synchronized with the video recordings. 14000 braking actions were analyzed.The results are useful for the design of active safety systems. For example, in some “natural” brakings, a fast accelerator pedal release, close to emergency situation actions, is relatively frequent on the road.A few of these actions are effectively linked to potentially dangerous situations. Taking into account other parameters, such as car’s speed,distance to precedent car or drivers driving style,may increase the emergency braking recognition.
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  • Analysis of braking and steering performance in car following scenarios Smith et al, SAE 2003-01-0283
    • This paper presents recent results of on-going research to build new maps of driver performance in car-following situations. The novel performance map is comprised of four driving states: low risk, conflict, near crash, and crash imminent - which correspond to advisory warning, crash imminent warning, and crash mitigation countermeasures. The paper addresses two questions dealing with the approach to quantify the boundaries between the driving states: (1) Do the quantified boundaries strongly depend on the dynamic scenario encountered in the driving environment? and (2) Do the quantified boundaries vary between steering and braking driver responses? Specifically, braking and steering driver performances are examined in two car-following scenarios: lead vehicle stopped and lead vehicle moving at lower constant speed. The analysis was conducted on experimental data collected from test track studies to develop a fundamental understanding of drivers' last-second braking and steering performance. The results of last-second braking performance analysis showed that the quantified boundaries depend on the dynamic scenario. On the other hand, the quantified boundaries were independent of the specific dynamic scenario based on the analysis of last-second steering performance. Finally, the quantified boundaries varied between braking and steering responses since drivers initiated last-second braking maneuvers at generally longer distances than last-second steering maneuvers.
  • Test track examination of driver’s collision avoidance behaviour using conventional and antilock brakes. NHTSA. Mazzae et al, NHTSA Report DT HS 809 561
  • Driver braking performance to surprise and expected events. Fitch et al. Proc Human factors and Ergonomics society 54th Annual Meeting, 2010
  • Driver related delay in emergency braking response to a laterally incurring hazard. Ising et al, Proc Human factors and Ergonomics society 56th Annual Meeting, 2012
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