What is Flexray?
For these automotive applications to become commonplace, a number of protocol requirements must exist. Enter FlexRay. FlexRay is a communication system developed by a consortium founded in 2000 by BMW, DaimlerChrysler, Motorola, and Philips Semiconductors. In 2001, Robert Bosch GmbH and General Motors joined the consortium. So did Ford Motor Company this past June. The consortium members realized that despite the numerous automotive communications protocols out on the market—most from Europe, most in or just out of development—none would fulfill future automotive control requirements. Even the computer communications protocols don’t suffice. “None of them are automotive qualified,” explains Andreas Both, business and technology manager overseeing FlexRay for the Semiconductor Products Sector of Motorola (Munich, Germany). That is, they are not qualified for automotive operating temperatures and electromagnetic compatibility requirements. (Remember hearing spark plugs fire through your aftermarket AM radio?)
FlexRay is an open, common, scalable electronic architecture for automotive applications. It can operate in single- or dual-channel mode, providing redundancy where needed. It allows both synchronous and asynchronous data transmissions. With the former, other nodes on the network receive time-triggered messages in a predefined latency time. With the latter, messages get to their destinations quickly or slowly, depending on their priority. Currently, FlexRay can handle communications at 10 Mbps—the speed of your typical low-end home-computing local area network. Motorola’s Both is quick to add that this standard doesn’t mean that 10 Mbps is enough forevermore. Instead, it is fast enough for the foreseeable future, given the applications automakers have envisioned thus far.
Last, FlexRay’s clock synchronization mechanism aptly handles cheap clock oscillators, namely those made out of quartz. And that synchronization, as with all of FlexRay, is fault tolerant. For example, FlexRay automatically and digitally compensates for the differences in the variety of quartz clocks running on the network, as well as in their slight changes in clock frequencies. This clock synchronization is a distributed mechanism; there’s no master timekeeper here. So if one node fails or for some reason is taken off the network, the other nodes will continue to operate in synchrony.
(Insofar as the fault tolerance of motors and sensors, the normal rules of reliable systems design applies. For example, in a steer-by-wire system, the sensor system in the steering wheel will be a redundant array, with two or three sensors providing the same signal. A judging algorithm in the electronics will then determine the validity of the signals; that is, it will determine whether all three sensors are providing the same information, or at least two of the three.)
Simplification=dollar savings
Along with making X-by-wire control possible, FlexRay offers other advantages. First, “any time you can get the control mechanism closer to the actual mechanism you’re trying to control, that’s a performance enhancer,” says Baker. Second, FlexRay helps eliminate the amount of mechanical space required for hydraulic fluid systems—systems that will be totally replaced by electronics. Third, continues Baker, FlexRay “provides the flexibility needed to simplify integration with current control system, reducing overall system complexity.” Therein lies a major advantage. Both OEMs and automotive suppliers are saying, says Both, “`We don’t need more [communications] technologies. We need less technologies that are more versatile.’ They want technologies that can be used over a range of applications.” That is, rather than have one by-wire protocol for steering and another for power train, FlexRay aims to be the protocol for all the applications. That’s one protocol applied across platforms, across assembly plants, across regions.
Not only will this simplify automotive electronics and communications architectures, it should also help make automotive electronics more stable.
FlexRay is aimed at the automotive market. No royalties will have to be paid for automotive applications. Prototype implementations of FlexRay-based chips are available for FlexRay Consortium members. First silicon of protocol engines will be available in early 2004; qualified silicon is scheduled for late 2004. Engineering samples of the electrical physical layer will be available from Philips Semiconductors in the second quarter of 2003; product parts by the end of 2004. First series production cars with FlexRay are expected around 2006.
The price of FlexRay devices, as with any semiconductor device, depends on silicon size, chip test efforts, commercial relationships with customers, and other criteria. None of these are fixed just yet.
For more information about the FlexRay Consortium and its FlexRay communications protocol, trawl over to www.flexray.com. Read the FAQ; it’s excellent. For additional information or if you have specific questions, send an email to request@flexray-group.com
For these automotive applications to become commonplace, a number of protocol requirements must exist. Enter FlexRay. FlexRay is a communication system developed by a consortium founded in 2000 by BMW, DaimlerChrysler, Motorola, and Philips Semiconductors. In 2001, Robert Bosch GmbH and General Motors joined the consortium. So did Ford Motor Company this past June. The consortium members realized that despite the numerous automotive communications protocols out on the market—most from Europe, most in or just out of development—none would fulfill future automotive control requirements. Even the computer communications protocols don’t suffice. “None of them are automotive qualified,” explains Andreas Both, business and technology manager overseeing FlexRay for the Semiconductor Products Sector of Motorola (Munich, Germany). That is, they are not qualified for automotive operating temperatures and electromagnetic compatibility requirements. (Remember hearing spark plugs fire through your aftermarket AM radio?)
FlexRay is an open, common, scalable electronic architecture for automotive applications. It can operate in single- or dual-channel mode, providing redundancy where needed. It allows both synchronous and asynchronous data transmissions. With the former, other nodes on the network receive time-triggered messages in a predefined latency time. With the latter, messages get to their destinations quickly or slowly, depending on their priority. Currently, FlexRay can handle communications at 10 Mbps—the speed of your typical low-end home-computing local area network. Motorola’s Both is quick to add that this standard doesn’t mean that 10 Mbps is enough forevermore. Instead, it is fast enough for the foreseeable future, given the applications automakers have envisioned thus far.
Last, FlexRay’s clock synchronization mechanism aptly handles cheap clock oscillators, namely those made out of quartz. And that synchronization, as with all of FlexRay, is fault tolerant. For example, FlexRay automatically and digitally compensates for the differences in the variety of quartz clocks running on the network, as well as in their slight changes in clock frequencies. This clock synchronization is a distributed mechanism; there’s no master timekeeper here. So if one node fails or for some reason is taken off the network, the other nodes will continue to operate in synchrony.
(Insofar as the fault tolerance of motors and sensors, the normal rules of reliable systems design applies. For example, in a steer-by-wire system, the sensor system in the steering wheel will be a redundant array, with two or three sensors providing the same signal. A judging algorithm in the electronics will then determine the validity of the signals; that is, it will determine whether all three sensors are providing the same information, or at least two of the three.)
Simplification=dollar savings
Along with making X-by-wire control possible, FlexRay offers other advantages. First, “any time you can get the control mechanism closer to the actual mechanism you’re trying to control, that’s a performance enhancer,” says Baker. Second, FlexRay helps eliminate the amount of mechanical space required for hydraulic fluid systems—systems that will be totally replaced by electronics. Third, continues Baker, FlexRay “provides the flexibility needed to simplify integration with current control system, reducing overall system complexity.” Therein lies a major advantage. Both OEMs and automotive suppliers are saying, says Both, “`We don’t need more [communications] technologies. We need less technologies that are more versatile.’ They want technologies that can be used over a range of applications.” That is, rather than have one by-wire protocol for steering and another for power train, FlexRay aims to be the protocol for all the applications. That’s one protocol applied across platforms, across assembly plants, across regions.
Not only will this simplify automotive electronics and communications architectures, it should also help make automotive electronics more stable.
FlexRay is aimed at the automotive market. No royalties will have to be paid for automotive applications. Prototype implementations of FlexRay-based chips are available for FlexRay Consortium members. First silicon of protocol engines will be available in early 2004; qualified silicon is scheduled for late 2004. Engineering samples of the electrical physical layer will be available from Philips Semiconductors in the second quarter of 2003; product parts by the end of 2004. First series production cars with FlexRay are expected around 2006.
The price of FlexRay devices, as with any semiconductor device, depends on silicon size, chip test efforts, commercial relationships with customers, and other criteria. None of these are fixed just yet.
For more information about the FlexRay Consortium and its FlexRay communications protocol, trawl over to www.flexray.com. Read the FAQ; it’s excellent. For additional information or if you have specific questions, send an email to request@flexray-group.com
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