The driving method of a robot is the core of its motion execution, and the selection should be based on requirements such as load capacity, accuracy, response speed, cost, and environmental adaptability. The following are the most commonly used driving methods for industrial, service, and special robots, classified and explained in detail according to principles and application scenarios:
1, Electric drive (most mainstream, suitable for most scenarios)
Converting electrical energy into mechanical energy through motors has advantages such as high precision, fast response, clean and pollution-free, and convenient control. It is currently the preferred driving method for robots, especially industrial robotic arms and service robots.
According to the type of motor, it can be divided into:
1. DC Servo Drive
Principle: Using a DC servo motor (with encoder feedback), combined with a driver to achieve closed-loop control of speed and position.
Features: Simple structure, low cost, high starting torque, low-speed stability, suitable for small and medium load scenarios.
Applications: Desktop robotic arms, small AGVs, service robots (such as sweeping robot walking wheels), educational robots.
2. AC Servo Drive
Principle: AC permanent magnet synchronous motor+encoder+servo driver, achieving high-precision position/torque control through vector control.
Features: High power density, strong overload capacity, low heat generation, long lifespan, suitable for high load and high-precision scenarios.
Applications: Industrial robotic arms (such as six axis collaborative arms, welding robots), high-end AGVs, CNC machine tool linkage axes.
3. Stepper Motor
Principle: The motor rotor is controlled to rotate step by step through pulse signals (without encoder, open-loop control), and the rotation angle is proportional to the number of pulses.
Features: Extremely low cost, simple control, no cumulative error (short stroke), but there is a "crawling" phenomenon at low speeds and weak load capacity.
Applications: Low end robotic arms, 3D printers, lightweight positioning mechanisms (such as small robot joints, push mechanisms).
4. Brushless DC motor drive (BLDC)
Principle: Non brush wear, controlled by an electronic commutator, combined with Hall sensors or encoders to achieve closed-loop control.
Features: High efficiency, low noise, long lifespan (no brush loss), between stepper motors and servo motors.
Applications: Service robot walking wheels, drone propellers, robot joints (low to medium load), medical robots (such as rehabilitation equipment).
5. Linear Motor Drive
Principle: Unfold the rotating motor and directly output linear motion (without the need for transmission mechanisms such as screws or gears).
Features: Zero transmission clearance, high speed and acceleration, extremely high positioning accuracy (up to micrometer level), but high cost and significant heat generation.
Applications: high-precision industrial robots (such as semiconductor handling robots), laser cutting equipment, high-end collaborative arm linear joints.
2, Hydraulic drive (suitable for heavy loads and harsh environments)
By converting the pressure energy of hydraulic oil into mechanical energy and using hydraulic cylinders or motors to output power, the core is the high-pressure oil source+control valve group.
Features:
Advantages: Extremely high power density (load capacity is several times that of electric vehicles under the same volume), strong impact resistance, high and low temperature resistance, dust and water resistance.
Disadvantages: Oil pollution, low control accuracy, slow response speed, and complex maintenance (requiring regular oil changes).
3, Pneumatic drive (suitable for light load, low-cost scenarios)
Using compressed air as the power source, motion is achieved through cylinders or pneumatic motors, with the core consisting of an air compressor, solenoid valve, and air circuit.
Features:
Advantages: Extremely low cost, simple structure, clean and oil-free (dry air), anti pollution (dust-proof, anti-corrosion), fast response speed (instantaneous start stop).
Disadvantages: Weak load capacity (only applicable to light loads), low positioning accuracy (compressible gas, prone to impact), and the need for supporting air compressors.
Overall, electric drive (especially AC servo) is currently the mainstream choice for robots, while hydraulic, pneumatic, and special drives serve as supplements, covering scenarios with extreme loads, environments, or precision requirements.