AEI's What's New at SAE 2002
Limited slip differential
The Super LSD (limited slip differential) from Tochigi Fuji Sangyo KK includes a core clutch developed to work well with the strut suspension found in front-wheel-drive vehicles. The unit also works well in the front axle of four-wheel-drive off-road vehicles. Compared to other torque-sensing LSDs, the super LSD has a lower torque bias ratio (1.5-2.0), which fits well with front suspension systems. Production costs are lower because of similarities to open differentials, and the device can be lubricated with standard differential fluid or ATF. The system can easily replace open differentials because it uses many of the same components and features identical installation points. The device provides good handling and control as well as a cost reduction.
Real-time controller
The COM20070A EC-NET Real-Time Communication Controller from Toyo Microsystems Corp. is an optimized network controller for embedded real-time control applications. Co-developed with Subaru, EC-NET was originally designed for use in automotive control networks, but its enhanced feature set and deterministic protocol make it suitable for embedded applications requiring real-time control. Subaru's first application of the system is in a control network for the various environmental and operational functions of buses. The system's features include high throughput, deterministic performance, mirroring RAM data, real-time clock adjustment, and improved token-passing protocol. A stand-alone mode allows the device to send and receive data without CPU intervention, thus eliminating the need for CPU, RAM, and Flash-ROM and resulting in lower per-node cost.
Communication controller
The TTP/C protocol is finding more applications in safety-critical systems such as those used in the automotive industry. TTTech Computertechnik AG's new TTP/C controller models are designed to meet the TTP/C specification and can be transferred to silicon as a stand-alone device or as part of an SOC solution. The C2 and C2S models allow communication at speeds up to 5 Mbit/s in asynchronous mode and 25 Mbit/s in synchronous mode. The configurable bus interface module affords 8-, 16-, or 32-bit width and either Intel or Motorola type accesses. The first TTP/C-C2 silicon implementation, a stand-alone controller, is available from Austriamicrosystems AG and has AS8202 as its device number. The firm will bring the C2S version, called AS8202S, on the market shortly after the AS8202. NEC is also implementing a stand-alone controller based on the TTP/C-C2S and supporting the full 32-bit host CPU bus interface.
Decoupling element
Witzenmann's KSE stainless steel decoupling component will be used by DaimlerChrysler for all 2002 Mercedes S-Class V8 turbo diesels. The decoupler eliminates noise in the engine and exhaust systems. The component is approximately 76 mm (3 in) wide by 51 mm (2 in) long. Designers started with the internal tube for exhaust gases, then covered it in multi-layer bellows with 3-5 corrugations. The unit is sleeved in a wire mesh ring, which further muffles noise.
Digital oscilloscope
Yokogawa's Model DL7200 four-channel, 2-Gs/s, 500-MHz bandwidth digital oscilloscope can trigger on and analyze CAN bus signals. The device's memory length—up to 16 Mword/channel—offers the ability to acquire many frames from a CAN bus. It can accommodate CAN bus rates from 33 kbps to 1 Mbps, as well as standard (11 bits) and extended (29 bits) data formats. It can trigger on start of frame, specified identifiers, RTR, specified data, and error frames. Once captured, the unit will analyze and display detailed CAN signal information in a binary or hex format.
