Motor types. When high power levels are needed, humanoid robots can incorporate motors such as permanent magnet synchronous motor (PMSM, a brushless AC motor that uses permanent magnets in its rotor to create a magnetic field). There are two options for PMSM motors: trapezoidal or sinusoidal winding. This choice of winding (and the control algorithm) affect how precisely the motor is controlled.
Brushed DC motors can be used in some low power cases such as hand and finger control. Product miniaturization has an effect on motor selection for many applications and there is associated complexity of the motor control and position feedback to achieve precise motion.
Motor control algorithms. After selecting a motor type, engineers must determine the method for how to control the motor. The control system is the brain of a humanoid robot. It processes the data received by the sensor system and provides commands to the actuators to act based on this decision process. Sophisticated algorithms help to reduce switching needs and losses of the motors FETs. High-performance MOSFETs or GaN FETs are needed to implement the drive and therefore increase motor efficiency.
Newer technologies, such as the GaN FET, improve switching performance compared to MOSFET-based systems. Gallium nitride field-effect transistors can have integrated gate drivers that push power-stage efficiency beyond 99%, allowing integrated motors to reduce or eliminate the need for a heat sink.
TI has many different MCUs which fit algorithm and angle sensor requirements. Important factors are the size of the IC and the real-time capability to enable high performance drive system. C2000 real-time microcontrollers and ARM-based microcontrollers are used in motor control algorithms. Learn more about motor and motion functions of humanoid robots. Learn more about motor and motion functions of humanoid robots.
Power stage requirements. The physical size available is another design consideration. Space constraints require higher power density and power efficiency. Small-size ICs and highly optimized power density designs are crucial to achieve small-space design goals. On the other hand high-power density leads to potential temperature limitations of the robot. Temperature management methods should not include additional cooling such as fans or liquids.
Current sensing is also an important design consideration when assessing power stage requirements; select appropriate current sensing parts to achieve desired performance levels. TI’s reference designs help you create a compact, efficient and fully protected power stage module for humanoid robots. TI’s analog and embedded processing products enable improved motor control performance and exceed isolation and EMC requirements.
Communications. Designing advanced humanoid robots requires a communication system that can support high-bandwidth, real-time data transfer across numerous joint controls, all within a space-constrained framework that remains reliable in noisy industrial environments.
Due to the location of the drives in the robot, optimizing communication with all drives while minimizing the amount of cabling is important. Typically, two key design parameters are data rate and cable size or length. In humanoid robots, Single Pair Ethernet (SPE) is used in either point-to-point or daisy-chain configurations to connect motor controllers that coordinate movement across various subsystems. TI offers both the physical layer (PHY) transceivers and embedded processors designed to enable these communication protocols. Learn how Single Pair Ethernet PHYs address these challenges and simplify system architecture.
