A six-dimensional force sensor is a high-dimensional force sensor capable of perceiving and measuring the three orthogonal forces (fx, fy, fz) and three orthogonal moments (mx, my, mz) in any force system in space. It belongs to the category of force sensing sensors. Force sensing sensors are widely used in robots and mechatronic devices as tactile sensors. Force and torque sensors are used to detect the internal forces of equipment or the forces interacting with the external environment. The physical quantity of force cannot be directly measured but can be indirectly measured through other physical quantities. Broadly speaking, a six-dimensional force sensor can check the three orthogonal forces (fx, fy, fz) and three orthogonal moments (mx, my, mz) in any force system in space. Due to its rich measurement and high measurement accuracy, it is mainly used in force and force-position control scenarios, such as force-controlled precision assembly, force-controlled precision polishing, robot drag teaching, and collision testing.

The inter-dimensional coupling of a six-dimensional force sensor refers to the fact that almost every force/moment component acting on the sensor in each dimension will affect the output signals of all channels of the sensor due to reasons such as the sensor's structural design, mechanical processing accuracy, patching technology, the transverse effect of strain gauges, and detection methods.

The protocols of six-dimensional force sensors include EtherCAT and Modbus communication protocols. EtherCAT is an optimized protocol for process data and can directly transmit within Ethernet frames due to its special Ethernet type. Modbus is an industrial device communication protocol that supports serial communication, Ethernet communication, serial-Ethernet conversion, and wireless communication methods. It supports various electrical interfaces, such as RS-232 and RS-485. The frame format is simple, compact, and easy to understand, making it easy for users and manufacturers to use and develop.

In some complex application scenarios, special performance tests should be conducted on the sensor, such as joint loading repeatability, joint loading deviation, measurement uncertainty, and elastic angular displacement.

Currently, the application fields of six-dimensional force sensors include helping robots achieve high-precision control and operation by measuring the force and moment at the robot's end, equipment detection, and control and navigation systems of aircraft. Currently, several domestic sensor manufacturers such as Kunwei, Yuli, and Landian are making great progress, and Keli Sensing is also entering this field. It can be seen that with the development of many humanoid robot manufacturers, the prospects for six-dimensional force sensors are also very broad.