Inventory of the world's latest automotive technology in 2011: chassis

GKN's disconnecting all-wheel drive system improves fuel efficiency by 2-4%

Within the AWD system, part-time drive (Part-Time AWD) can switch between two-wheel drive and all-wheel drive modes by connecting or disconnecting the transfer case according to different road conditions. This is also the driving mode of most off-road vehicles or four-wheel drive SUVs.

Based on this idea, GKN launched a new disconnecting all-wheel drive system and put it into production, and revealed that the drive system can improve fuel efficiency by about 2-4%.

AWD disconnect is more of a method than a specific system. While much of the technology behind disconnecting AWD is not new, it is a rethinking of the existing system for the GKN Driveline portfolio. AWD disconnect will join the existing transaxle, AWD and eDrive portfolio.

Cooper AVON ZZ5 tire uses asymmetric tread

Cooper Tire & Rubber Company’s AVON brand has launched a new model of the ZZ5 tire, which uses an intelligent asymmetric tread IATD design, has superior grip and can be used on European regional roads and racetracks.

The application of the Intelligent Asymmetric Tread Design (IATD) technology not only gives the vehicle excellent traction and maneuverability on dry roads, but also improves the drainage gap efficiency on wet roads and makes the tread load more balanced. In order to continue to improve high performance, the latest AVON ZZ5 tire has optimized noise suppression technology to make driving quieter.

Chevrolet Sonic gets hill start assist

General Motors has equipped the 2012 Chevrolet Sonic compact car with Hill-hold technology. This technology can help drivers start manual transmission vehicles smoothly on steep roads and prevent the vehicle from sliding down due to the release of the foot brake during acceleration. General Motors figuratively compares this electronic device to the "third leg (Extra Foot)" that helps the driver to step on the foot brake.

For manual transmission vehicles, starting uphill may be difficult. When releasing the foot brake and switching to the accelerator pedal, the vehicle may stall, and the gravity component of the steep slope may cause a backward slide, which may easily cause an accident. The design of the hill start assist technology is just for this situation, achieving the control effect of an automatic transmission vehicle.

The Hill-hold device is essentially connected to the brake system through an electronic sensor. When the vehicle is stationary on a road with a slope greater than 3%, if the door is closed and the gear is in "forward (uphill)" or "reverse (downhill)", the driver steps on the brake pedal, the sensor will detect the tilt of the vehicle body and send a signal to the vehicle stability control system, the system will trigger the electronic brake, and the Hill-hold function will be activated.

ZF nine-speed automatic transmission replaces CVT in 2013

Germany's ZF announced that it has begun developing a nine-speed drive axle/transmission for front-wheel drive sedans with transverse engine layouts.

Fast, smooth shifting will be a hallmark of the new nine-speed automatic transmission. Similar to the eight-speed automatic transmission for longitudinal engines, the nine-speed automatic transmission, although used with a transverse engine driving the front wheels, offers the same agile response and extremely short shift times.

Similar to the eight-speed automatic transmission for longitudinal engines, the nine-speed automatic transmission, although used for front-wheel drive transverse engines, also has agile response characteristics and extremely short shifting time. This means that double shifts and direct multiple gearshifts will become a reality. Therefore, the new nine-speed automatic transmission and eight-speed automatic transmission both have "sports genes".

TRW upgrades software to improve electronic power steering system performance

TRW Automotive announced that a range of advanced steering functions can be added to the Electronically Powered Steering (EPS) system by programming it into software.

The number of relevant functions can be freely selected by the automaker to help drivers correct the vehicle's "error state" and improve driving safety.

For example, the frequency, degree and quality of the power steering assist function are adjusted by software: when the vehicle is running at low speed (such as parking in a parking lot), the Full Assist function enables the vehicle to perform small-radius turns; while when driving at high speed on the road, the chassis including the steering system has high rigidity and high sportiness. All of the above modes can be selected by the driver.

BMW's adaptive intelligent eight-speed transmission system can predict road conditions

BMW said it is developing an adaptive intelligent eight-speed transmission that can predict road conditions and make timely gear adjustments, taking the initiative and intelligence of the transmission system a step further.

The current powertrain is already able to receive gear change instructions from the transmission control system, achieving greater flexibility and accuracy under various driving conditions. The predictive transmission control system uses a variety of information collection methods. In addition to the driver's own naked eye observation, a variety of other observation methods can also provide the driver with data on road conditions, road topography and traffic conditions to help the driver choose the most ideal gear.

To achieve this, in the early stages of developing the new adaptive intelligent eight-speed transmission, BMW designers linked the transmission control system to BMW's exclusive Dynamic Stability Control (DSC) function and the on-board navigation system. The DSC system provides lateral assistance to the Traction Control System, which controls longitudinal balance.

New concept Uni-Chassis lightweight chassis

Chris P. Theodore, a former Ford and Chrysler executive, developed a new concept Uni-Chassis lightweight chassis. The new design has the characteristics of low weight, low cost and adaptability to electric vehicles.

The Uni-Chassis chassis has a unique configuration: automobiles usually adopt a combined or frame-type (Body-on-frame) structure; while the Uni-Chassis chassis connects the powertrain and front and rear suspension components to a rigid tubular keel frame, thereby eliminating the original frame. The Uni-Chassis chassis adopts a front-engine rear-wheel drive configuration. The rigid tubular keel frame structure essentially plays the role of a large torque tube, but the surrounding side frames (Side Frame) are eliminated.

Aluminum castings reduce welds and eliminate battery support structures. Chris P. Theodore believes that the Uni-Chassis chassis can reduce weight by more than 10%. Reducing chassis weight can reduce the demand for battery power, and small-capacity batteries will significantly reduce vehicle costs. In addition, the cast aluminum Uni-Chassis chassis has room for cost reduction compared to traditional aluminum racing car structures.

Prius α sprung mass vibration reduction control and electrical equipment estimation technology

Toyota Motor's Prius α model uses Denso's Estimation Technology for the vehicle's sprung mass vibration control system.

Toyota Motor is responsible for developing the body control technology, while Denso's estimation technology is used to assist in the estimation. The sprung mass damping control system estimates the body pitching speed (pitch frequency) based on the wheel speed/rim linear speed. Based on this estimated value, the motor torque of the hybrid system can be controlled to reduce the body pitch frequency. The sprung mass damping control system can improve ride comfort and handling stability by reducing the pitch frequency of 1-2 Hz.

The longitudinal force on the tire contact patch can be estimated from the output of the wheel speed sensor embedded in the front wheel. Based on the longitudinal force figure, the force acting on the suspension and body interface can be calculated, and the vehicle's pitch velocity can be estimated accordingly.

Nexteer uses thermoplastic coupling to reduce noise for EPS

To solve the acoustic and vibration problems of EPS installed on the column base, Nexteer has developed a lightweight and flexible plastic coupling to replace the original steel coupling. EPS equipped with this type of thermoplastic coupling will be used in models such as Citroen DS3.

Nexteer's newly developed highly flexible thermoplastic coupling significantly reduces the effects of noise conduction while also reducing weight, creating the quietest EPS on the market.

The new coupling uses a highly flexible ribbed pad to transfer torque between the rotating shafts while playing a connecting role. The coupling can be extended or compressed to provide the required axial stroke and achieves the function of a fully matched drive shaft constant velocity joint/ball cage.

THT develops CGVT continuously variable gear meshing transmission

THT exhibited the fifth generation of TH-Mission technology at the 2011 SAE Annual Meeting. The core of TH-Mission is the continuously gear-meshed variable transmission (CGVT), which has the advantages of small size and low power loss.

The continuously variable gear meshing transmission system CGVT reuses the transmission gears abandoned by ordinary CVT, has an "extremely simple structure", and does not place high demands on manufacturing and processing technology. Since the gears are always meshed, the power transmission loss is minimized, thereby improving the power performance. In addition, the CGVT transmission system is also characterized by small size and light weight. At present, the volume of the CGVT transmission system sample is only 1/5 of the size of the Audi S Tronic-7 transmission.

Similar to CVT, it is equivalent to "smooth and gentle transition between thousands of gears, switching between torque output and speed". Therefore, TH-Mission has "minimum energy loss" when reaching the maximum speed.