According to Tesla's second quarter briefing, it is expected that in this month, Tesla can produce a humanoid robot equipped with self-designed actuators, and carry out walking and execution tests.

Walking test is a key part of Tesla humanoid robot's small-batch pre-production in 2024. It is expected to mainly investigate the robot's upright balance dynamic motion, scene perception and decision-making ability, and the linear joints of lower limbs are expected to be the key test objects.  

IMU Inertial Measurement Unit (IMU), also known as Inertial Measurement Unit, is a device that measures the three-axis attitude Angle (or angular rate) and acceleration of an object. It is mostly used in devices that need motion control, such as automobiles and robots. MEMS IMU=MEMS gyroscope +MEMS accelerometer.

The main difficulty of IMU is to solve the error and improve the accuracy. The error of MEMS IMU comes from the error of the inertial sensor itself, and the error generated by the IMU during the integration process. The above two kinds of errors can be divided into systematic errors and random errors. Among them, the systematic errors mainly include zero bias errors, non-orthogonal errors, nonlinear errors, temperature errors, etc. In addition to solving each systematic error method, random errors can also be calibrated after the algorithm, usually using the Allan variance method, which is also one of the barriers.

IMU is a key sensor for humanoid robots to maintain balance and motion control. The inertial information such as angular velocity and acceleration collected by the inertial sensor can be used to calculate the real-time position and motion trajectory of the humanoid robot. At the same time, it can be integrated with the multi-sensors carried by the robot to achieve complementarity between data types and data frequencies.

In other words, the IMU can be integrated with multi-sensor data such as cameras and force sensors on the robot to achieve functions such as maintaining body balance, predicting speed and trajectory, and positioning and navigation, which is expected to be standard on quadruped robots and humanoid robots.

According to the UCLA paper, the Artermis robot places a 3DM tactic-grade IMU in the pelvis, with an integrated headcamera and affordable alternatives in the foot.

According to the accuracy requirements, IMU can be divided into consumer grade, industrial grade, tactical level, according to the different principles can also be divided into MEMS IMU, optical fiber IMU, humanoid robots generally use more than 1,000 yuan of high-performance MEMS IMU.

Automatic driving to L3 level and above, the required IMU accuracy needs to reach 1 degree /h, the current high-precision MEMS IMU chip all rely on overseas imports. To achieve the accuracy of Tesla Optimus, humanoid robots need to increase the number of high-precision MEMS IMUs to achieve the effect of body stability, attitude control and head instability compensation, so the opportunity of domestic autonomous control of high-performance MEMS IMU chips needs to be arranged in advance.

China's MEMS IMU market concentration is high, Bosch, ST and TDK, Analog, Honeywell occupy about 93% of the market, the market share of domestic MEMS IMU manufacturers is almost negligible.

At present, there are mainly three types of domestic MEMS IMU/ inertial sensor players: high-performance MEMS chip autonomous controllable semiconductor companies, such as chip, Mattel Technology, Minghao sensing, etc., more scarce; Local consumer MEMS leaders, such as Shilanwei, Sai Microelectronics, etc., are mainly oriented to the field of consumer electronics, of which Sai Microelectronics is a MEMS foundry enterprise; Tier 1 system integrators, such as Huayi Technology, Star Network Yuda, etc., mainly layout IMU-INS module/system integration, sensor chips are imported.

High-precision MEMS IMU is expected to benefit from the outbreak of humanoid robots and autonomous driving demand in the future, and there is a large space for cost reduction after upstream domestic replacement and civil scale.

The "Humanoid Robot Innovation and Development Guidance" issued by the Ministry of Industry and Information Technology, which mentioned that to form a humanoid robot innovation system in 2025, the initial establishment should make breakthroughs in a number of key technologies such as "brain", "cerebellum" and "limb", to ensure that the core components of humanoid robots can be effectively supplied, the whole machine level reaches the world's advanced level, and achieve mass production. At the same time, the guidelines also raise humanoid robots to the fourth category of important products with the same status as smart phones, new energy vehicles and computers.