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7 Post Shaker
The 7 post shaker is a piece of test equipment used to perform technical analysis on race cars. By applying shaking forces the shaker can emulate banking loads, lateral load transfer, longitudinal weight transfer and ride height sensitive downforce to emulate specific racetracks. Uses The 7 post shaker is used for many vehicles in different driving conditions. Earlier versions were the 5 post shaker and the 4 post shaker. The 4 post shaker is commonly used by vehicle manufacturers to investigate squeaks and rattles. Manufacturers do not normally use a 7 post rig for road cars because these vehicles are not normally subject to the same aerodynamic effects as a race car operating at high speeds. This technology was first used in Formula 1 in the late 1990s, and is now also used by other series such as NASCAR and the Indy Racing League. NASCAR teams with 7 post rigs include Hendrick Motorsports, Richard Childress Racing, Chip Ganassi Racing, Furniture Row Racing, and Roush Fenway ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indy Racing League
The IndyCar Series, currently known as the NTT IndyCar Series under sponsorship, is the highest class of regional North American open-wheel single-seater formula racing cars in the United States, which has been conducted under the auspices of various sanctioning bodies since 1920 after two initial attempts in 1905 and 1916. The series is self-sanctioned by its parent company, INDYCAR, LLC., which began in 1996 as the Indy Racing League (IRL) and was created by then Indianapolis Motor Speedway owner Tony George as a competitor to Championship Auto Racing Teams (CART). In 2008, the IndyCar Series merged with CART's successor, the Champ Car World Series and the history and statistics of both series, as well as those from its predecessors, were unified. The series' premier event is the Indianapolis 500, which was first held in 1911. Overview Series name For 1996–1997, the series was simply referred to as the ''Indy Racing League.'' For 1998–1999, the series garnered its firs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Accelerometers
An accelerometer is a tool that measures proper acceleration. Proper acceleration is the acceleration (the rate of change of velocity) of a body in its own instantaneous rest frame; this is different from coordinate acceleration, which is acceleration in a fixed coordinate system. For example, an accelerometer at rest on the surface of the Earth will measure an acceleration due to Earth's gravity, straight upwards (by definition) of g ≈ 9.81 m/s2. By contrast, accelerometers in free fall (falling toward the center of the Earth at a rate of about 9.81 m/s2) will measure zero. Accelerometers have many uses in industry and science. Highly sensitive accelerometers are used in inertial navigation systems for aircraft and missiles. Vibration in rotating machines is monitored by accelerometers. They are used in tablet computers and digital cameras so that images on screens are always displayed upright. In unmanned aerial vehicles, accelerometers help to stabilise flight. W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASCAR
The National Association for Stock Car Auto Racing, LLC (NASCAR) is an American auto racing sanctioning and operating company that is best known for stock car racing. The privately owned company was founded by Bill France Sr. in 1948, and his son, Jim France, has been the CEO since August 2018. The company is headquartered in Daytona Beach, Florida. Each year, NASCAR sanctions over 1,500 races at over 100 tracks in 48 US states as well as in Canada, Mexico, Brazil and Europe. History Early stock car racing In the 1920s and 1930s, Daytona Beach supplanted France and Belgium as the preferred location for world land speed records. After a historic race between Ransom Olds and Alexander Winton in 1903, 15 records were set on what became the Daytona Beach Road Course between 1905 and 1935. Daytona Beach had become synonymous with fast cars in 1936. Drivers raced on a course, consisting of a stretch of beach as one straightaway, and a narrow blacktop beachfront highway, Florid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unsprung Mass
The unsprung mass (colloquially unsprung weight) of a vehicle is the mass of the suspension, wheels or tracks (as applicable), and other components directly connected to them. This contrasts with the sprung mass (or weight) supported by the suspension, which includes the body and other components within or attached to it. Components of the unsprung mass include the wheel axles, wheel bearings, wheel hubs, tires, and a portion of the weight of driveshafts, springs, shock absorbers, and suspension links. Brakes that are mounted inboard (i.e. as on the drive shaft, and not part of the wheel or its hub) are part of a vehicle's sprung mass. Effects The unsprung mass of a typical wheel/tire combination represents a trade-off between the pair's bump-absorbing/road-tracking ability and vibration isolation. Bumps and surface imperfections in the road cause tire compression, inducing a force on the unsprung mass. The unsprung mass then reacts to this force with movement of its o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suspension (vehicle)
Suspension is the system of tires, tire air, springs, shock absorbers and linkages that connects a vehicle to its wheels and allows relative motion between the two. Suspension systems must support both road holding/ handling and ride quality, which are at odds with each other. The tuning of suspensions involves finding the right compromise. It is important for the suspension to keep the road wheel in contact with the road surface as much as possible, because all the road or ground forces acting on the vehicle do so through the contact patches of the tires. The suspension also protects the vehicle itself and any cargo or luggage from damage and wear. The design of front and rear suspension of a car may be different. History An early form of suspension on ox-drawn carts had the platform swing on iron chains attached to the wheeled frame of the carriage. This system remained the basis for most suspension systems until the turn of the 19th century, although the iron cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shock Absorber
A shock absorber or damper is a mechanical or hydraulic device designed to absorb and damp shock impulses. It does this by converting the kinetic energy of the shock into another form of energy (typically heat) which is then dissipated. Most shock absorbers are a form of dashpot (a damper which resists motion via viscous friction). Description Pneumatic and hydraulic shock absorbers are used in conjunction with cushions and springs. An automobile shock absorber contains spring-loaded check valves and orifices to control the flow of oil through an internal piston (see below). One design consideration, when designing or choosing a shock absorber, is where that energy will go. In most shock absorbers, energy is converted to heat inside the viscous fluid. In hydraulic cylinders, the hydraulic fluid heats up, while in air cylinders, the hot air is usually exhausted to the atmosphere. In other types of shock absorbers, such as electromagnetic types, the dissipated energy can be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scrub Radius
The scrub radius is the distance in front view between the king pin axis and the center of the contact patch of the wheel, where both would theoretically touch the road. It can be positive, negative or zero. The kingpin axis also known as steering inclination is the line between the upper and lower pivot points of the steering knuckle. If the kingpin axis intersection point is outboard of the center of the contact patch, it is negative; if inside the contact patch, it is positive. The term scrub radius derives from the fact that either in the positive or negative mode, the tire does not turn on its centerline (it scrubs the road in a turn) and due to the increased friction, more effort is needed to turn the wheel. Large positive values of scrub radius, 4 inches/100 mm or so, were used in cars for many years. The advantage of this is that the tire rolls as the wheel is steered, which reduces the effort when parking, provided you're not on the brake. The advantage of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roll Center
The roll center of a vehicle is the notional point at which the cornering forces in the suspension are reacted to the vehicle body. There are two definitions of roll center. The most commonly used is the geometric (or kinematic) roll center, whereas the Society of Automotive Engineers uses a force-based definition.An Introduction to Modern Vehicle Design edited by Julian Happian-Smith P293 Definition * Geometric roll center is solely dictated by the suspension geometry, and can be found using principles of the instant center of rotation. * Force based roll center, according to the US Society of Automotive Engineers, is "The point in the transverse vertical plane through any pair of wheel centers at which lateral forces may be applied to the sprung mass without producing suspension roll". The lateral location of the roll center is typically at the center-line of the vehicle when the suspension on the left and right sides of the car are mirror images of each other. The signif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nyquist Rate
In signal processing, the Nyquist rate, named after Harry Nyquist, is a value (in units of samples per second or hertz, Hz) equal to twice the highest frequency (bandwidth) of a given function or signal. When the function is digitized at a higher sample rate (see ), the resulting discrete-time sequence is said to be free of the distortion known as aliasing. Conversely, for a given sample-rate the corresponding Nyquist frequency in Hz is one-half the sample-rate. Note that the ''Nyquist rate'' is a property of a continuous-time signal, whereas ''Nyquist frequency'' is a property of a discrete-time system. The term ''Nyquist rate'' is also used in a different context with units of symbols per second, which is actually the field in which Harry Nyquist was working. In that context it is an upper bound for the symbol rate across a bandwidth-limited baseband channel such as a telegraph line or passband channel such as a limited radio frequency band or a frequency division mult ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Automotive Suspension Design
Automotive suspension design is an aspect of automotive engineering, concerned with designing the suspension for cars and trucks. Suspension design for other vehicles is similar, though the process may not be as well established. The process entails *Selecting appropriate vehicle level targets *Selecting a system architecture *Choosing the location of the 'hard points', or theoretical centres of each ball joint or bushing *Selecting the rates of the bushings *Analysing the loads in the suspension *Designing the spring rates *Designing shock absorber characteristics *Designing the structure of each component so that it is strong, stiff, light, and cheap *Analysing the vehicle dynamics of the resulting design Since the 1990s the use of multibody simulation and finite element software has made this series of tasks more straightforward. Vehicle level targets A partial list would include: *Maximum steady state lateral acceleration (in understeer mode) *Roll stiffness (degrees pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Automobile Handling
Automobile handling and vehicle handling are descriptions of the way a wheeled vehicle responds and reacts to the inputs of a driver, as well as how it moves along a track or road. It is commonly judged by how a vehicle performs particularly during cornering, acceleration, and braking as well as on the vehicle's directional stability when moving in steady state condition. In the automotive industry, handling and braking are the major components of a vehicle's "active" safety, as well as its ability to perform in auto racing. The maximum lateral acceleration is sometimes discussed separately as "road holding". (This discussion is directed at road vehicles with at least three wheels, but some of it may apply to other ground vehicles). Automobiles driven on public roads whose engineering requirements emphasize handling over comfort and passenger space are named sports cars. Factors that affect a car's handling Weight distribution Centre of mass height The centre of mass hei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
4-poster
A 4-poster or four poster automotive test system is specifically designed for the testing of vehicles (cars, trucks). These test systems consist of 4 hydraulic actuators on top of which the wheels of the vehicle are placed. Movements of the actuators simulate the road surface and forces exerted by the road on the wheels. The movements of the system are tightly controlled by a digital test controller. During the research phase of a vehicle a 4-poster system is used to test newly designed suspension systems and their durability. In production 4-poster systems are usually used to test every vehicle at the end of the production line on squeak and rattle, which is a check to make sure the vehicle doesn't have any loose parts. Different kinds of testing are possible: sine test (sweep in frequency); simple wave form on each actuator; open loop test (driven by an external tension signal); a particular testing method called ICS control, which allows to reproduce on a car an actual service en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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