Posts Tagged ‘failure analysis’
Tesla Motors’ autonomous vehicle system technology is progressing at a rapid rate towards being offered as an option on their vehicles. The autonomous system is being perfected to work in everyday driving situations to allow the vehicle’s driver to completely disengage from controlling the vehicle and allow the car to do all of the driving functions. Tesla has been developing their autonomous system for some time, and the system has undergone much iteration to get to the point at which it is capable of controlling a vehicle. Unfortunately, the current system, while very robust and dependable, is still prone to errors caused by circumstances that are unexpected under normal driving situations. Exact situations have not been shared, however speculations as to very quick moving obstacles in the path of travel, or even very small obstacles in the path of travel are thought to cause the autonomous system to fail. Driverless cars in general, including Tesla Motors, are under extreme scrutiny because of the significant dangers involved if a driverless car control system fails. Serious injury, property damage, or even death are all possible outcomes if a driverless car fails to operate properly.
Tesla’s driverless autonomous vehicle system consists of a multitude of cameras and sensors that are supposedly capable of detecting objects around the vehicle as well as signage along the path of travel. Signs, such as stop signs or other warning indicators such as stop lights are identified by the driverless car and the car’s operation is changed appropriately to these signals. While the software behind controlling the vehicle’s sensors and cameras is currently still in development, the vehicles themselves are now being produced with the necessary hardware that will allow the cars to drive themselves in the near future. The software will be released as part of an update to the vehicle’s computer system and can be updated without significant maintenance to the vehicle.
Taken from Motor1
Researchers from Stanford University are experimenting with a new technology that is aimed at reducing injury severity caused by bicycle helmets. Current bicycle helmet design consists of a hardened foam or plastic shell that covers the upper half of a rider’s skull and reduces the impact forces present during a head to ground impact. New helmet technology includes the use of inflatable air bladders that cover the head in a similar fashion to most traditional helmets. The inflatable air bladders, similar to automotive airbags, cushion the head during an impact with a pillow of air. Current testing by Stanford researchers has shown that airbag helmets can reduce head impact forces by as much as five to six times over forces present in impacts with traditional helmets. Most foam bicycle helmets have been shown to significantly reduce significant impacts, reducing the likelihood of cranial fractures, concussions, or other head injuries. Airbag helmets are a promising step in the direction of reducing such injuries even more.
Much of the current research done at Stanford consists of properly understanding the mechanics behind brain injuries due to impacts with the ground or other hard surfaces. Research into the damage to brain tissue has shown that concussions occur when brain cells stretch or twist torsionally. During an impact, the brain may collide with the side of the rider’s skull, causing a collision within the head between the skull wall and the brain itself. Energy is absorbed by the brain in severe impacts by the brain matter itself. Obviously damage to the brain can occur if the impact is severe enough. Helmets capable of reducing impact severity, such as the airbag helmet, are already hitting the market in some European countries.
One main potential drawback to the airbag helmet design as a mainstream product is due to the fact that an airbag helmet’s effectiveness at reducing injury is only as good as the amount of cushioning provided by the airbag. If the airbag is not properly inflated with high-pressure air prior to impact, the helmet becomes significantly less effective at absorbing impact forces. Proper inflation of the airbags is therefore extremely important. Current versions of airbag helmets are not consistently providing sufficient air pressure to the airbag, rendering the helmets less effective at preventing injury.
The future of airbag helmets will rely on more thorough testing of the helmets that are more representative of actual impacts. Current testing procedures do not effectively model the occupant’s head, neck, and associated mechanics thoroughly enough to gain proper testing data. Further testing and development of the airbag inflation devices is also necessary to create a product that ensures proper inflation and a more robust inflation rate.
from Science Daily
Federal regulators and the auto industry are taking a more lenient approach than safety advocates would like when it comes to phasing in automatic braking systems for passenger cars, according to records of their private negotiations. The technology automatically applies brakes to prevent or mitigate collisions, rather than waiting for the driver to react. While such systems are already available in dozens of car models, typically as a pricey option on higher-end vehicles, they should be standard in all new cars, according to safety advocates. But instead of mandating it, the government is trying to work out a voluntary agreement with automakers in hopes of getting it in cars more quickly.
The Associated Press has obtained the Meeting minutes from three of the meetings that NHTSA has held with automakers since October which show that the government is considering granting significant concessions. Records of the third negotiating session, on Nov. 12, show that automatic braking systems would be allowed that slow vehicles by as little as 5 mph before a collision. Furthermore, manufacturers may be allowed to exempt 5 percent of their vehicles from the standard with an additional exemption for models that manufacturers intend to phase out or redesign. The minutes don’t specify a model year by which the technology would have to be included in cars, but the group did decide that discussion of any deadline would begin with “the latest date submitted by any automaker” for when they would be ready to make the change.
Meeting participants included NHTSA, 16 automakers, two auto industry trade groups and the Insurance Institute for Highway Safety (the insurance industry’s safety research arm). Representatives from Transport Canada, the Canadian government’s auto safety regulator, also attended.
NHTSA estimates show that there are about 1.7 million rear-end crashes a year in the U.S., killing more than 200 people, injuring 400,000 others and costing about $47 billion annually. More than half of those crashes could be avoided or mitigated by automatic braking or systems that warn drivers of an impending collision. NHTSA announced last year that it will include automatic braking and other collision-avoidance technologies in its five-star safety rating program to encourage automakers to more widely adopt the technology.
In an unusually pointed criticism, the National Transportation Safety Board, which investigates accidents and makes safety recommendations, said in a report last year that “slow and insufficient action” by NHTSA to develop performance standards for automatic braking and collision warning systems and to require the technologies in cars and trucks “has contributed to the ongoing and unacceptable frequency of rear-end crashes.”
NHTSA says a badly-designed automatic shifter is confusing drivers, causing them to exit a vehicle that’s still in gear. 121 crashes and 30 injuries have been reported.
This past summer the National Highway Traffic Safety administration opened a preliminary investigation into just over 400,000 Jeep Grand Cherokees after some owners alleged their vehicles would roll away after being shifted into Park. Now, the NHTSA has more than doubled the number of Jeep, Dodge and Chrysler vehicles being investigated and the agency now blames the problems on a confusing shifter design that doesn’t adequately indicate to drivers that they haven’t engaged Park.
The Detroit News reports that the NHTSA is conducting an engineering analysis on more than 856,000 Fiat Chrysler vehicles. The agency has received reports of 314 roll-away incidents, involving 121 crashes and 30 injuries, caused when drivers exited a vehicle after they thought they’d shifted into Park. And while the initial investigation treated the issue as a mechanical defect, it’s looking more and more like the problem has at least something to do with driver error due to a poorly-designed shifter.
The investigation involves 3.6-liter V6-powered 2014 and 2015 Jeep Grand Cherokees, 2012-2014 Dodge Chargers and 2012-2014 Chrysler 300s—all of which use a push-button console shift lever that looks like a traditional PRNDL shifter. But in operation, the electronic shifter works more like a joystick, returning to its center position once you’ve selected your gear. There is no gate around the shifter; the lever itself moves through somewhat subtle detents, and the whole range of motion is incredibly short compared to a traditional mechanical shifter, perhaps two or three inches from end to end.
The console shifter on a 2014 Jeep Grand Cherokee. The Dodge Charger and Chrysler 300 models included in the investigation use an identical shifter.
It’s worth pointing out that the aforementioned Fiat Chrysler vehicles are not the only ones that use this shifter, which is called the Monostable and is produced by transmission supplier ZF. As an example, Audi A8 uses an identical shift knob, with the thumb button on the left and a PRNDS gear pattern with no separate button for Park.
In testing, NHTSA found that the electronic gear shifter’s operation is “not intuitive” and offers “poor tactile and visual feedback to the driver, increasing the potential for unintended gear selection.” In Fiat Chrysler vehicles equipped with this shifter design, opening the driver’s door when the car is not in Park triggers a chime and an instrument cluster alert, and the engine cannot be turned off with the car in gear; however, NHTSA says “this function does not protect drivers who intentionally leave the engine running or drivers who do not recognize that the engine continues to run after an attempted shut-off.”
So while it may seem silly that drivers could be confused by the operation of an automatic transmission, the reality is that this shifter design operates differently enough to require more concentration than a traditional shifter. Folks who’ve been driving for years, who are used to the way a mechanical PRNDL shifter operates, probably don’t think consciously about the act of shifting—it’s the kind of act we’ve committed to muscle memory years ago.
NHTSA has upgraded its treatment of this problem in FCA vehicles from an investigation to an “engineering analysis,” though no plans for a recall have been announced at this time. FCA went to a different shifter design in model-year 2015 for the Dodge Charger and Chrysler 300, and changed the Jeep Grand Cherokee shifter for 2016.
via Detroit News
Harley-Davidson announced that it is recalling just over 19,000 Dyna and Softail motorcycles from the 2012 model year because the threads for the brake line banjo bolt in the front brake master cylinder may corrode. If the threads corrode, a sudden loss of brake fluid could result, causing a loss of the front brakes. Dealers are asked to flush and inspect the front brake master cylinder and, if necessary, replace the master cylinder. NHTSA recall campaign number is 14V794000 and is expected to begin Jan. 14.
Models affected are the 2012 FXST103, FLSTC, FLSTC103, FLSTF, FLSTF103, FXDL, FXDWG, FXDWG103, FXDC, FXDB, FLSTN, FLSTN103, FLSTC103 Shrine, FLSTFB, FLSTFB103, FXS, FXS103, FLS, FLS103, FLD, FLD103, and FXDF and FXDF103 motorcycles manufactured from Aug. 22, 2011, through Feb. 24, 2012, for the United States and some world markets. This totals 19,015 units, Harley-Davidson told NHTSA.
“We have voluntarily declared this a defect related to motor vehicle safety (Campaign 0163 for the Softail model and Dyna model motorcycles and 0164 for the FXDF/FXDF103 model motorcycles) to allow us to formally recall all affected motorcycles. Two recalls are needed to cover all affected models because of the differences in the kit component content required for the two populations,” the Motor Co. informed dealers. “Based on warranty information, the prediction for motorcycles requiring master cylinder replacements is extremely low,” Harley-Davidson said in its notification to dealers. Dealers are permitted to sell but must not deliver any of the affected motorcycles until the remedy is complete, the OEM added.
Yamaha Motor Corp. recently announced that it is recalling about a small number of 2014 YZF-R6 supersport motorcycles to replace wheels that may have not been properly hardened during manufacturing. Although the recall notice only cites 28 potentially affected units, the bikes in question may have front and rear wheels that have not been properly treated, preventing them from achieving the correct hardness for durability and safe running. Potential effects of the improper heat treatment are that the wheels could loosen or the tire sealing may be inadequate; either situation could increase the risk of a crash.
Yamaha has already notified owners, and will replace both front and rear wheel and tire assemblies on the affected bikes free of charge. Owners may contact Yamaha customer service at 1-800-962-7926 and reference Yamaha’s recall number: 990088.
As with all NHTSA recalls, owners may also contact the NHTSA Vehicle Safety Hotline at 888-327-4236 or go to www.safercar.gov.
At this point, most people have heard of the “black box” or flight data recorder that is used to reconstruct the details of an airplane accident. (But did you know that despite the nickname, these FDRs are not black at all, but are actually painted a bright orange for easier visibility after a crash?
Many people also know that semi-trucks and passenger cars also have their own version of an accident recorder.
These devices make it much easier to know exactly what happened in an accident. They are used by the NTSB and any other agencies looking into the accident, as well as attorneys who might be representing any involved party in a lawsuit.
But what kind of forensic engineering is available in motorcycle accidents? There’s no black box recording speed, or even who hit who. For motorcycle accidents, it’s beneficial to have someone who’s an expert in motorcycle operation, construction, and dynamics to examine any physical evidence.
An investigation into the causes and circumstances surrounding a motorbike accident focuses on three phases:
1. The braking stage
2. The sliding phase
3. The impact phase
Every detail of the evidence is taken into consideration, including any skid marks, the state of the road’s surface, the weather conditions, and the damage sustained by the motorcycle. Damage to any other vehicles or property involved is considered an important part of the evidence as well.
Along with an inspection of the accident scene, accident reconstruction experts may perform brake tests, performance tests, and even visibility studies when necessary, in the course of their investigations.
Accidents happen quickly. For every person who says they saw their accident happening “in slow motion,” there are many others for whom it occurs so quickly, they cannot offer any good information about exactly what happened. Even if there are witnesses, their testimony about an accident is frequently quite varied, as we each perceive and remember things very differently.
Therefore, the role of an expert motorcycle accident reconstructionist is vital to really understanding what happened.
An insurance industry study reports that the average medical claim from a motorcycle crash rose by more than one-fifth last year in Michigan. What accounts for such a dramatic rise? The state passed a law no longer requiring all riders to wear motorcycle helmets. And many motorists took advantage of their new freedom, hitting the road sans helmet.
Across the nation, motorcyclists opposed to mandatory helmet use have been chipping away at state helmet laws for years while crash deaths have been on the rise.
According to the study done by the Highway Loss Data Institute, the average insurance payout for a motorcycle injury claim was approximately $5,410 the two years prior to the law being changed, when helmets were mandatory for all riders. After the new law went into effect, the average payment rose to $7,257— a 34 percent jump.
The Highway Loss Data Institute is part of the Insurance Institute for Highway Safety (IIHS), a nonprofit organization dedicated to reducing the losses sustained from crashes on the nation’s roads. This includes personal and property losses.
The Highway Loss Data Institute (HLDI) supports this mission through scientific studies of insurance data and by publishing insurance loss results.
According to HLDI’s chief research officer David Zuby, “The cost per injury claim is significantly higher after the law changed than before, which is consistent with other research that shows riding without a helmet leads to more head injuries.”
This particular study is the first one to take a specific look at the consequences repealing helmet laws have on the severity of injuries as measured by medical insurance claims. Although some states have set minimum medical insurance requirements for motorcyclists, “that doesn’t even come close to covering the lifelong care of somebody who is severely brain-injured and who cannot work and who is going to be on Medicaid and a ward of the state,” according to Jackie Gillan, president of Advocates for Highway and Auto Safety.
Giving an opposing opinion, Vince Consiglio of American Bikers Aimed Toward Education of Michigan, claimed bikers not taking the required safety courses was the real cause of the increase in injuries. According to Consiglio, bikers without motorcycle licenses make up an increasing share of fatalities and injuries.
Nationwide, motorcycle fatalities are on the rise, even as many states are weakening or repealing helmet laws. The fatality rate for riders has gone up for 14 of the past 15 years. The Governors Highway Safety Association reported 5,000 deaths in 2012—14 percent of overall traffic deaths for that year.