1. Six-dimensional force/torque sensor: the ceiling of force sensors, domestic brands are accelerating to catch up with overseas mainstream
Six-dimensional force/torque sensor stands at the top of force sensors, and strain gauge type is the mainstream
Force/torque sensor can convert the value of force or torque into relevant electrical signals. According to the different dimensions of the measured force, it can be divided into one-dimensional force and multi-dimensional force sensor. One-dimensional force sensor can only measure force or torque in a single dimensional direction, and multi-dimensional force sensor can detect force or torque in multiple dimensional directions.
Six-dimensional force/torque sensor is the highest dimensional force sensor, and the detected force information is the most comprehensive. Six-dimensional force/torque sensor (hereinafter referred to as six-dimensional force to represent six-dimensional force/torque sensor) can simultaneously measure the force along the three coordinate axes and the torque around the three coordinate axes. Therefore, when the direction and point of action of the force change randomly in three-dimensional space, a six-dimensional force sensor should be selected. The six-dimensional force sensor can not only measure force accurately, but also use the torque information to calculate the posture of the force-bearing component after obtaining the torque information; at the same time, it monitors whether the torque is within the safe range to effectively avoid overload damage to the sensor.
There are rich categories of six-dimensional force sensors, each with its own scope of application. At this stage, strain gauges are the mainstream. According to the technical principle, six-dimensional force sensors can be divided into strain gauges (silicon strain and metal foil), optical and piezoelectric/capacitive sensors. Each type of sensor has its unique advantages and scope of application. Comparing the stability, stiffness, dynamic characteristics, signal-to-noise ratio and cost of the sensors, silicon strain gauges are superior to metal foils in stability, signal-to-noise ratio and dynamic characteristics, but silicon strain gauges are more expensive; compared with piezoelectric sensors, capacitive sensors have the best cost, and the other several items are weaker than piezoelectric sensors; optical sensors have advantages in dynamic characteristics.

The product has high barriers, and three indicators evaluate the advantages and disadvantages of six-dimensional force

The six-dimensional force sensor is a category with high barriers. The core barrier of the six-dimensional force sensor lies in the technical end, including the inter-dimensional coupling affecting the measurement accuracy, the complex operation of "all-round mechanical overload protection", and the difficulty in measuring "dynamic performance". The solution to key technical problems requires strict processing accuracy, strong product performance and cutting-edge intelligent algorithms; at the same time, the equipment side requires six-dimensional joint loading equipment for calibration and testing, and equipment research and development involves multiple comprehensive technologies. Therefore, on the whole, high technical barriers are beneficial to leading companies with long-term accumulation.

The three major performance indicators for judging the quality of six-dimensional force sensor products: crosstalk, precision and accuracy. 1) The crosstalk index is used to measure the coupling effect between the measurement directions of the six-dimensional force sensor, which can reflect the level of measurement error; 2) Precision and accuracy can accurately describe the measurement error level of the six-dimensional force sensor, among which precision measures the repeatability between the measurement results, and accuracy measures the degree of deviation of the measurement results from the theoretical true value. 3) Accuracy covers error factors such as hysteresis, linearity, and creep, which can better reflect the comprehensive performance of the product and is one of the most core technical indicators of the six-dimensional force sensor.