차량 규격 용어

• 전장(Overall Length): 자동차의 전체 길이
• 전폭(Overall Width): 사이드미러를 제외한 상태에서의 차량의 너비가 가장 넓은 폭
• 전고(Overall Height): 지면에서 자동차 지붕 위까지의 높이
• 축거(Wheel Base): 앞바퀴 중심과 뒷바퀴 중심사이의 거리 (Wheel Base가 길면 회전반경이 커진다. $\delta=\frac{L}{R}$)
• 윤거전(Front Tread): 앞바퀴간의 거리
• 윤거후(Rear Tread): 뒷바퀴간의 거리
• 프론트 오버행(Front Overhang): 앞바퀴 중심에서 앞범퍼까지의 거리
• 리어 오버행(Rear Overhang): 뒷바퀴 중심에서 뒷범퍼까지의 거리

Reference Coordinate Systems

CAN(Controller Area Network)

CAN is a serial communications protocol which efficiently supports distributed realtime control with a very high level of security.

CAN 개요 설명

Standard CAN

• SOF: The single dominant start of frame (SOF) bit marks the start of a message, and is used to synchronize the nodes on a bus after being idle.
• Identifier: The Standart CAN 11-bit identifier establishes the priority of the message. The lower the binary balue, the higher its priority.
• RTR: The single retmote transmission request (RTR) bit is dominant when information is required from another node. All nodes receive the request, but the identifier determines the specified node. The responding data is also received by all nodes and used by any node interested. In this way, all data being used in a system is uniform.
• IDE-A: Dominant single identifier extension (IDE) bit means that a standard CAN identifier with no extension is being transmitted.
• r0: Reserved bit
• DLC: The 4-bit data length code (DLC) contatins the number of bytes of data being transmitted.
• Data: Up to 64 bits(8 bytes) of application data may be transmitted.
• CRC: The 16-bit (15 bits plus delimiter) cyclic redundancy check (CRC) contains the checksum (number of bits transmitted) of the preceding application data for error detection.
• ACK: Every node receiving an accurate message overwrites the recessive bit in the original message with a dominate bit, indicating an error-free message has been sent. Should a receiving node detect an error and leave this bit recessive, it discards the message and the sending node repeats the message after rearbitration. In this way, each node acknowledges (ACK) the integrity of its data. ACK is 2 bits, one is the acknowledgment bit and the second is a delimiter.
• EOF: Thie end-of-frame (EOF), 7-bit field marks the end of a CAN frame (message) and disables bit-stuffing, indicating a stuffing error when dominant. when 5 bits of the same logic level occur in succession during normal operation, a bit of the oposite logic level is stuffed into the data.
• IFS: This 7-bit interframe space (IFS) contains the time required by the controller to move a correctly received frame to its proper position in a message buffer area.

Extended CAN

• SRR: The substitue remote request (SRR) bit replace the RTR bit in the standara message location as a placeholder in the extended format.
• IDE: A ressicve bit the identifier extension (IDE) indicates that more identifier bits follow. The 18-bit extension follows IDE.
• r1: Following the RTR and r0 bits, an additonal reserce bit has been included ahead of the DLC bit.

Arbitration (중재)

The allocation of message priority is up to a system designer, but industry groups mutually agree on the significance of certain messages. For example, a manufacturer of motor drives may specify that message 0010 is a winding current feedback signal from a motor on a CAN network and that 0011 is the tachometer speed. Because 0010 has the lowest binary identifier, messages relating to current values always have a higher priority on the bus than those concerned with tachometer readings.

CAN Bus

The two signal lines of the bus, CANH and CANL.