An Underwater Thruster Fault Diagnosis Simulator and Thrust Calculation Method Based on Fault Clustering

Table 1

Data frame composition.

Frame header (2 bytes)	Frame instruction (1 byte)	Frame length (1 byte)	Frame content (5 bytes)	Check sum (1 byte)
AA BB	01	Frame content length, 05	Low voltage byte (note 1)	Frame header, frame instruction, frame length, and frame content
			Voltage high byte (note 1)
			Current low byte (note 2)
			Current high byte (note 2)
			Speed (note 3)

Voltage value = (voltage high byte << 8 + voltage low byte)/10; if voltage low byte is 0×EE, high byte is 0x00, and voltage value is 23.8 V. Current value = (current high byte << 8 + current low byte)/10; if current low byte is 0×01, high byte is 0×00, and current value is 0.1 A. The speed is a signed value, where 0×FF indicates reverse 1st gear and 0×01 indicates 1st gear; example 1: AA BB 01 05 EE 00 01 00 01 5B; among them, AA BB is the data header, which does not need to be analyzed; 01 05 is the fixed data without parsing; EE 00 is the voltage value; that is, the hexadecimal 00EE is converted to 238, and the voltage value divided by 10 is 23.8 voltage and low byte is 0×EE V.