# Development of a Power and Communication Bus Using HIL and Computational Intelligence
## 1 Introduction  
The first car design by [PERSON] in 1885 [1] had an elementary harness, which merely involved high voltage cables to spark plugs. In 1915 [2], the Ford Motor Company implemented electric headlamps and horns, soon followed by turn signals, electric wipers, and other equipment. In the 1980s, Bosch proposed the first data interface, called the Controller Area Network (CAN) [3], for reducing the number of wire harnesses. Nowadays, cars are equipped more and more with electronic systems [4], Electronic Control Units (ECU) and interfaces. The typical low-speed CAN is limited to 125 kpbs, a classic CAN is limited to 1 Mbps, and CAN FD is limited to 3-5 Mbps depending on the environment. A Local Interconnect Network (LIN) is commonly used in communication with comfort devices or non-safety sensors, due to the lack of hardware redundancy and low speed (typically 20 kpbs). FlexRay, which was developed to be faster and more reliable than other protocols, is used for safety critical applications and allows the transferring of data up to 10 Mbps [5]. Ethernet is used for high-speed-requiring devices, such as cameras in autonomous driving, and a typical baud rate is 100 Mbps or 1000 Mbps [6]. Autonomous driving raises communication techniques to a higher level, using the newest and the fastest technology of wireless techniques such as 5G for V2X communication [7, 8, 9]. Unfortunately, point-to-point wiring is still being used. As can be read in papers [10; 11], a harness can weigh from 15 kg in a combustion engine car, to about 20 kg in a small EV, to 91 kg in luxury vehicles [12]. The mass of the vehicle has a significant influence on energy consumption [13], but nowadays, EVs partly solve this problem by using recuperation [14]. Based on [10] it can be stated that a harness can cost up to 1000 USD. The harness' simplicity can significantly reduce weight, cost and risk of failure during operation. When it comes to small devices, of which many are used in a car (e.g., ambient light, sensors, actuators), Original Equipment Manufacturers (OEMs) have three solutions--using a separate wire for each device (this increases cost, weight and geometrical sizes of the harness), the same hardware but different software, where the address is programmed (this increases effort during production, and the risk of mixing devices which have the same shape), or auto-addressed modules on the line. There are a few solutions for auto-addressing available on the market; one of them from Melexis [15], another from Texas Instruments [16] named \"Automatic slave node detection\", and a patent describing auto-addressing [17] is available for RS485 [18]. All solutions require wires, commonly one additional, which gives four lines including power supply. Focusing on reducing the number of wires in the automotive industry, there is only one solution that uses the same wires for transferring power and data, but not command. The company Yamar [19] proposed special chips to \"inject\" multiple interfaces to a power line. Depending on the chip used, one can achieve a data speed from 9.6 Kbps to 500 kbps. This solution has a few disadvantages: cost (7 EUR for CAN chip) and size (mainly peripheral components, coils, capacitors, and one crystal resonator). For a hardware engineer who designs a new device, one of the goals is to use as few components as possible, due to three reasons: more elements generate higher production costs (single component, assembly, maintenance), potential issues (hidden defects, production issues, supply chain issues), size (each element requires more space on the PCB (Printed Circuit Board). Researchers [20] attempted to send data using Yamar SIG60 (the oldest solutions from Yamar) with unsatisfactory results--the interface was working, but it was relatively slow at only 57.6 kbps and the researchers got no transmission error. Unfortunately, there are no more studies with the newest solutions from Yamar. In the industry, we can find the AS-I [21] interface, where data and power are sent on the same line.