![\"\"](\"https:\/\/blogs.sw.siemens.com\/wp-content\/uploads\/sites\/24\/2020\/02\/Fig-1-Car-interior-1024x683.jpg\")
A key competitive factor for\ncustomers in an electric vehicle is range. The more miles a vehicle can drive\nwith one charge, the better. Vehicle mass plays a key role in determining a\nvehicle\u2019s range, therefore, minimizing weight in an electric vehicle is crucial\nto bringing a competitive and successful vehicle to market. New vehicle\ntechnologies, however, require additional electrical wiring and other\nelectronic components, increasing the weight of the vehicle. The introduction\nof the electric powertrain alone adds about 30% more weight compared to an\ninternal combustion engine powertrain.<\/p>\n\n\n\n
Autonomous driving requires the\naddition of a multitude of hardware redundancies and fail safe mechanisms to\nprevent single points of failure that could disable the autonomous system\nunexpectedly. System redundancies are critical because unexpected failures may\ncause the vehicle to crash if the driver isn\u2019t paying attention or actively\ninvolved in the driving and steering process. However, these safety\nredundancies can add significant weight and cost to the wiring harness by\nduplicating networks, powerlines, and some electronic control units (ECUs).<\/p>\n\n\n\n
Vehicles are also becoming highly connected as part of the internet of things and internet of vehicles, transforming the vehicle into a seamless interface between our connected lives at home and at work. The integration of screens and displays into almost any imaginable interior surface demonstrates the vehicle\u2019s growing role as a hub for entertainment, communications, and productivity. All this technology has to be connected together, driving OEMs to incorporate more networks, such as CAN, and leading to wiring harnesses that are heavier, larger, costlier, and more complex (figure 2). Some modern vehicles contain close to 40 different harnesses, comprised of roughly 700 connectors and over 3000 wires. If taken apart and put into a continuous line, these wires would exceed a length of 2.5mi (4km) and weigh approximately 132lbs (60kg). In addition, OEMs will need to integrate high baud rate networks with specialty cabling to support the increased features and functionality of new vehicles. Modern vehicles can contain more than 70 specialty cables, such as coax, high speed data, and USB cables. In older cars, this number was closer to 10.<\/p>\n\n\n\n How can today\u2019s automotive\nmanufacturers solve the Content Dilemma? Via the introduction of methods that\nhelp development teams to reduce the impact of added content and technology on\nthe weight, cost, complexity, and packaging space required for wiring\nharnesses. <\/p>\n\n\n\n One solution is to develop\ntechnologies that reduce harness weight. Ultra -small diameter wiring (0.13mm2<\/sup>)\nis one good example. Unfortunately, the industry is still struggling to develop\na sufficient number of terminal substitutions for all currently existing\nterminals that can crimp to such a small wiring diameter. Reducing the wire\nsize on common circuit types, such as CAN busses, can achieve quick weight\nsavings without necessitating a complex subset of connectors and pins, but the\navailable products on the market currently do not support a large-scale\nmigration to ultra-small diameter wiring. <\/p>\n\n\n\n Finding alternatives to\nspecialty cables will further reduce the weight, cost and bundle diameters of\nharnesses. The number of cameras and displays will only increase in the future.\nOEMs must balance between using high baud rate networks that require specialty\ncabling and installing a greater quantity of lower baud rate networks, based on\nthe resulting cost, weight, complexity, and risk of the harness. In the near\nterm, widely used standards, such as CAN FD, that provide higher baud rates\nwhile operating on inexpensive twisted pair wiring may provide an easier and\nlower risk upgrade path. Alternatively, finding ways to multiplex these signals\nonto one shared specialty cable and having multiple devices tap into these\ncables will have the same effect: reducing harness weight, cost and bundle\ndiameter.<\/p>\n\n\n\n Another approach is using advanced software solutions, such as Capital, part of the Xcelerator portfolio, that support tradeoff studies to optimize module locations and identify any modules that can be combined to save weight, cost, and reduce bundle sizes (figure 3). The ability to compare and analyze layouts for their impact on harness weight, cost and bundle diameter will enable engineers to choose the most optimal system architecture.<\/p>\n\n\n\n![\"\"](\"https:\/\/blogs.sw.siemens.com\/wp-content\/uploads\/sites\/24\/2020\/02\/Fig-2-vehicle-networks-1024x562.jpg\")
![\"\"](\"https:\/\/blogs.sw.siemens.com\/wp-content\/uploads\/sites\/24\/2020\/02\/Fig-3-ADAS-LVL3-1024x626.png\")