The automobile industry inclusive of the off highway and mobile machinery are cost sensitive at the same time technology craving industries. To keep pace with the technological advancements these industries constantly invest heavily in research and development projects. These projects vary from electronics to mechanics to offer a greater customer experience, performance, safety and much more. Communication plays a vital role in vehicles and currently these industries are in search of a next generation fieldbus satisfying all industry requirements along with providing an enhanced performance.
Importance of Communication
In today’s age of data and information, it is of prime importance to not only exchange data but also to do it safely and securely. CANopen is widely used in automotive, off highway and mobile machinery for exchanging information. Over the years, the amount of data exchanged has increased exponentially and in the future will continue to grow. With the addition of sensors, IOs, and cameras the bandwidth requirements have escalated. Camera integration on a vehicle was unthinkable a couple of year back. As a feature available in the vehicle in the minds of the users it has moved from a ‘good to have’ to a ‘must have’ feature. CANopen being based on serial communication limits in these bandwidth requirements. Consequently exhausting all the available resources, the industry is in search of the next generation fieldbus, which provides a common backbone for all communication.
CANopen also has a number of variants providing higher speeds. However, Ethernet based communication is the obvious choice, which provides higher speeds and larger bandwidth. Like CANopen it is a manufacturer independent open technology. However, the carrier sense multiple access with collision detection (CSMA/CD) mechanism plagues Ethernet communication. This is generally not suitable for achieving a deterministic and real time communication at the sensor level. In addition, it is prone to hacks and security breaches. Apart from the deterministic aspect the number of interfaces a manufacturer has to equip the Electronic Control Units (ECUs) grows with the addition of features supporting different communications.
With the size of electronics reducing day-by-day and vehicle light-weighting gaining prominence, if the number of interfaces keep on increasing he will not be able to keep pace with the industry demands.
POWERLINK a logical addition to CAN
Imagine achieving the openness, features, determinism and robustness of CANopen coupled with speeds and hardware of Ethernet. This is not a concept but is currently available and used in mobile and off highway machinery extensively. Ethernet POWERLINK is simply termed as CANopen over Ethernet. It thus combines the features of CANopen and standard Ethernet for enhanced performance and bandwidth. Just imagine the benefits the manufacturers gain with this combination, one network for transmitting sensor data, IO data, GUI data and even camera live feeds. POWERLINK is a communication standard based on standard Ethernet. It is a truly software implementation to achieve deterministic, real time communication with cycle times down to 100µs. This software is completely open source and is available free of cost with no license fees, patents and copyrights. As no hardware modifications are required, it is not tied to a particular physical layer used for communication and thus can work with copper cables, fiber optic or even wireless. The technology offers a complete multi-master, media and ring redundant systems which can help in making the vehicle available at all times and provide a degree of safety with redundant ECUs.
Ligthweighting with features and performance
Many would argue that CANopen uses two wires cabling whereas Ethernet uses four wires or POE could use four or eight wires depending on the IEEE standard selected and this increases the weight on the vehicles. In automotive the technology from Broadcom known as BroadR-Reach has gained recognition due to its ability to transmit data and power over a twisted pair cable. POWERLINK communication has been successful tested over this technology with a cycle time of 250µs. Thus, now users can benefit from the wiring of CANopen for POWERLINK and at the same time get the advantages of Ethernet based deterministic communication.
The requirements of automotive and off highway and mobile machinery are very diverse. Automotive needs a higher bandwidth for transferring audio and video signals whereas off highway and mobile machinery has a requirement for deterministic and real time communication. POWERLINK satisfies both these requirements comfortably.
Secure communication from cloud to field level
In automotive as well as mobile and off highway machinery safety is critical. Humans and vehicles are at stake in this industry. Just using the safety devices does not provide a safe solution. The communication should also be safe in order to guarantee complete safety. Looking at the different networks used in automotive and off-highway equipments it is impossible to have separate safety protocols for different networks. Keeping these aspects in mind we have come up with openSAFETY. openSAFETY is the world’s first and only TUV certified safety protocol which is fieldbus independent and completely open source. Thus the safe data can be exchanged between field devices or multiple ECUs.
Availability of data is not only necessary when we are in the car or driving it, but it could be essential to access the data at all times. This is where the connected car or the Industry 4.0 approach is important. However, we should be aware that the data has to be sent securely to the cloud for access over the internet and received securely from the cloud. With OPC UA, another open source platform independent technology based on standard Ethernet we can guarantee the transmission security of data right from the cloud to the controllers. It will soon be possible to have an application on your phone and gather data from the vehicle securely without a possibility of a hack or invasion.