Servo Electric Actuator

Servo Electric Actuator (SEA)

Servo Electric Actuator (SEA)-based End-of-Line and durability testing for automotives

Servo-electric actuator (SEA) technology is bringing about a transformational change in the automotive durability testing. The SEA technology provides several benefits that enhance the efficiency and effectiveness of durability testing of automobiles.
The precision offered by the SEA enables testers to replicate real-world scenarios more closely, ensuring that the durability testing accurately reflects the conditions vehicles may encounter during their lifespan.
eMpulse Test Systems is a world leader in servo-electric road simulation and vibration test equipment, tailored for the automotive, mobility, and aerospace industries. Leveraging its SEA technology, eMpulse offers a wide range of versatility and custom solutions that are tailored to meet the specific needs of its customers.

Servo-Electric Actuator (SEA) technology: How it works

The Servo Electric actuator (SEA) features a modular actuator assembly to accept numerous motor/permanent magnet combinations. This optimally matches the continuous peak force as well as the required velocity of the test requirements.

It also features DC bushless linear servo motors that operate on a DC bus voltage. This is obtained from a 3-phase AC rectifier circuit (Line Module). The Incoming power of the servo motors is 380-480VAC and typical performance specifications are based on the lower end of this range

The higher capacities are available when operated on higher voltages common in most areas. The technology does not re quire transformers.

The motors are designed with liquid cooling to the fixed forcer, or primary, which significantly more effective at removing heat which limits the continuous force ratings of servo electric motors. In addition, liquid cooling provides much quicker recovery from peak loads, providing more uptime and higher duty cycle usage than other air-cooled designs.

Additionally, both power cables and liquid cooling are designed to be fixed, as only the secondary magnets are moved. This further eliminates the failure modes of cable flex and cooling line ruptures.

The actuator assembly includes an absolute (not incremental) high resolution optical encoder. Resolution internal to the motor controls is 1nm, with 1um resolution available for data analysis.

Key benefits of eMpulse’s SEA technology

Improved reliability: A less complicated actuator assembly resulting in fewer parts yields an increase in reliability and lower maintenance costs.

Higher accuracy: SEA systems are not affected by many physical constraints that cause reduced system accuracy and repeatability. These variables include oil viscosity changes with temperature, accumulator pressure, servo valve wear, flow restrictions, seal friction, hydraulic resonances, and oil contamination.

Increased performance: SEA can achieve higher velocities at higher forces, with 3X higher frequency response, resulting in lower RMS errors than hydraulic systems.

Greater efficiency: In comparable use cases, SEA systems use less than 20% of the electrical energy compared to hydraulic systems.

Safer operation: The SEA eliminates the potential for high pressure oil leaks and related environmental pollution. The SEA also utilizes safety integrated functions that allow for safety limited acceleration, velocity and force (current) to be configured for specific applications or testing.

Improved troubleshooting: Smart diagnostics capability within the controls can direct operators to the specific hardware causing a fault condition.

Remote log-in capability: Allows eMpulse engineers to aid in troubleshooting anywhere in the world.

Reduced maintenance: Servoelectric actuators are compact, easy to install, and require minimal maintenance, resulting in lower overall system costs.

Cleaner environment: Hydraulic fluids can be hazardous to the environment, and the process of disposing of used fluids can be costly and complex. Servoelectric systems do not require any fluids, making them a cleaner and safer alternative.

SEA Road Simulator – 4 Post for Durability, EOL & NVH Testing

SEA road simulators play a pivotal role in durability, end-of-line & NVH testing by replicating real-world driving conditions within a controlled environment.

Road simulators are pivotal in durability testing, offering a controlled and consistent setting to assess vehicle performance across diverse driving conditions. Through exposing vehicles to accelerated wear and tea and replicating real-world scenarios, engineers can detect and rectify durability concerns at an early stage of development, resulting in vehicles that are more dependable and long-lasting.

Road simulators subject vehicles to simulated road conditions over extended periods, helping to identify potential issues related to durability and performance, meeting the purpose of end-of-line testing to ensure that vehicles meet quality and durability standards before they leave the production line.

Using the servoelectric actuators (SEA), eMpulse Test Systems road simulators are designed to replicate real-world driving conditions, including road surfaces, terrain, and environmental factors. eMpulse offers a range of systems that can simulate a wide variety of driving conditions, from city streets to highways to off-road environments.

The road simulator also supports Buzz, Squeak and Rattle (BSR) testing and Noise, Vibration and Harshness (NVH) testing.

SEA Damper Testing for Durability and Performance

Essential for simulating mechanical stresses and loads on vehicle components, there are two load frame testing techniques - elastomer and damper testing. Damper testing evaluates a material’s ability to absorb energy, while elastomer testing assesses its mechanical properties.

Servo-electric load frames from eMpulse Test Systems help test the performance, durability, and service life of essential automotive components, including shock absorbers, dampers, struts, and more.

Designed to replace servo hydraulics and exceed the performance of other electric options, the patent pending SEA Series of Damper Test systems from eMpulse Test Systems provide a clean, efficient, and dynamically responsive solution for both performance and durability damper testing.

The damper testers from eMpulse comprised of three standard models of varying peak dynamic force capacities: 10kN, 21kN, and 41kN. The SEA damper testers can achieve significantly higher continuous loads which make them an excellent choice for extended duration durability testing.

    Key benefits of SEA load frame testing

  • • Energy Efficient
  • • Quiet Operation
  • • Full Digital Control with Built-In Diagnostics
  • • High Continuous Dynamic Force Capacity
  • • Precise Control
  • • High Bandwidth
  • • Liquid or Air Cooled

SEA Multi Axial Simulation Table (MAST) for Durability Testing

The seaMAST has been designed and can be configured to meet the needs of diverse industries, products, and applications. They are available in hexapod systems and orthogonal systems.

Hexapod systems offer versatility. Hexapod systems can provide motion and force in all 6 degrees-of-freedom, which makes them well-suited for applications that require complex motion. Hexapod systems can also offer high accuracy, repeatability, and frequencies in excess of 200 Hz.

Orthogonal systems typically consist of 3 Vertical actuators, with a combination of at least 1 actuator in a horizontal axis opposed by 2 actuators in the other horizontal axis to fully provide true 6 degrees-of-freedom in X, Y, Z, Roll (rotation about the X axis), Pitch (rotation about the Y axis), and Yaw (rotation about the Z axis).

By optimizing the system to specific combinations of stroke, velocity, and acceleration performance, orthogonal systems are easily adapted to meet customer-specific needs.

Custom configurations are often designed for project and application specific requirements.

Advanced Safety Features: SEA systems provide a cost-effective alternative for a number of safety features. These can be easily configured inside our control system without the need for costly equipment upgrades.

  • • Safe Limited Speed (SLS)
  • • Safe Limited Acceleration (SLA)
  • • Absolute Encoder monitoring and fault detection
  • • System-wide Safe Torque Off (STO) operation
  • • Internal temperature monitoring of all components
  • • Customizable limits to specimen-specific parameters