Head Impact Test Rig, engineered for impacts up to 250 km/hr.

1. Introduction

The Head Impact Test Rig is a highly specialized electro-hydraulic testing system engineered to assess the safety performance of vehicle seat headrests. Built to simulate the real-world impact of a human head during a vehicular collision, this rig helps determine the structural behaviour of seat systems under dynamic loading conditions. The machine is capable of capturing critical parameters such as impact force, seat deflection, and energy absorption, making it an indispensable tool in automotive R&D, regulatory compliance, and quality-assurance environments.

This system combines high-precision mechanical design with intelligent software control and robust safety features to offer consistent, repeatable, and accurate testing performance.

2. System objective

The primary goal of this test rig is to simulate the impact of a 6.8 kg Head Form at velocities of up to 250 km/hr, allowing for a wide range of impact scenarios — from low-speed urban collisions to high-speed highway crashes. This flexibility makes the system suitable for advanced safety research and development. The machine captures the deflection of the headrest, the acceleration experienced during the impact, and the energy absorbed by the seat. The data is critical for evaluating occupant protection and designing seats that comply with the most stringent automotive safety standards.

3. Mechanical structure

At the heart of the system is the Head Form, a 6.8 kg aluminium body featuring a hemispherical head of 165 mm diameter. The form is mounted on Linear Motion (LM) Guide Rods, which ensure smooth vertical movement and accurate impact alignment. To simulate realistic impact, a servo-hydraulic actuator delivers a controlled downward force, triggered by a closed-loop servo valve system.

The seat to be tested is mounted on a heavy-duty M.S. bed (1500 mm × 1500 mm), which is lifted into testing position using a scissor lift with a 3000 kg load capacity. This ensures rigidity and vibration damping during the impact. The entire setup is enclosed in an acrylic safety housing, offering operator protection while maintaining visibility.

• Headform Mass: 6.8 kg
• Impact Velocity: Adjustable up to 250 km/hr
• Headform Shape: Hemispherical, 165 mm diameter
• Seat Platform Size: 1500 × 1500 mm
• Scissor Lift Capacity: 3000 kg
• Material Construction: Aluminum (Head Form), Mild Steel (Bed and Frames)
• Guide Rod Parallelism: < 8 microns

4. Sensors and instrumentation

To ensure high precision and repeatability, the rig is equipped with a set of calibrated sensors and transducers. The accelerometers embedded in the Head Form measure the impact force in g-forces, while LVDTs (Linear Variable Differential Transformers) measure headrest deflection with sub-millimeter accuracy.

Fiber-optic velocity sensors positioned along the guide rods calculate the Head Form's speed just before impact. These sensors are crucial for verifying that each test run matches the set test velocity. A laser sensor is also included to verify the correct placement and height of the test seat before initiating the impact cycle.

• Accelerometers: Measure impact force in g
• LVDT: Measures seat headrest deflection
• Velocity Sensors: Dual fiber-optic slots (A1: 10.189 mm, A2: 10.218 mm)
• Laser Sensor: Ensures correct seat alignment
• Pressure & Temperature Transducers: Monitor hydraulic system conditions

5. Control system and software

The rig is operated via an industrial-grade touchscreen PC, preloaded with proprietary software. The software interface is user-friendly, guiding the operator step-by-step through machine initialization, test execution, and data review. Test data is stored in editable Word format and can be exported, printed, or integrated into a report management system.

A secure login system restricts test access to authorized personnel, enhancing safety and traceability. The software is designed to automatically check sensor statuses, ensure system pressure, and generate real-time warnings before every impact.

• Touchscreen-based interface for easy navigation
• Pre-test system checks (sensors, pressure, temperature)
• Automated impact and data acquisition
• Editable report generation with graphs (g vs. time)
• Easy installation on Windows OS via provided installer

6. Hydraulic system

A robust hydraulic power pack is responsible for generating the required pressure for impact. It includes an 80-liter reservoir, high-precision filters, and a servo-controlled manifold. The system uses ISO VG68 petroleum-based oil and is equipped with temperature and clogging indicators for maintenance alerts. The entire unit is integrated with the machine's control logic for seamless pressure buildup and release.

• Reservoir Capacity: 80 Liters
• Oil Type: ISO VG68
• Max System Pressure: 250 kg/cm² (3450 PSI)
• Filtration: 10-micron (return line), 149-micron (suction line)
• Servo Valve: For precision flow control and actuator movement
• Pressure Regulation: Software-driven with digital feedback

7. Applications

The Head Impact Test Rig is an essential piece of equipment for automotive OEMs, seat manufacturers, safety testing labs, and research institutions. It is used for:

• Evaluating occupant safety and seat structural integrity
• Product validation during the development phase
• Quality control testing in production environments
• Compliance verification with safety norms such as AIS, ECE, and Euro NCAP
• Generating test data for regulatory and certification bodies

Its modular design and fully documented software make it suitable for integration with broader vehicle crash-simulation programs and laboratory data acquisition systems.

8. Preventive maintenance and safety

Preventive maintenance tasks include checking oil levels, cleaning and replacing filters, verifying the functionality of the accelerometers and LVDTs, and inspecting cable routing. The software includes built-in alerts for most of these tasks. Safety mechanisms such as an emergency stop, pre-impact warnings, and mechanical locks ensure the operator's well-being during each test cycle.

The Head Form is securely tied with a steel rope to prevent free fall in the event of system failure, and all wiring is routed cleanly to avoid any interference with moving parts.

Technical specifications at a glance

9. Documentation and deliverables

• Operator Manual
• Software Installation Media
• Calibration Certificates for all sensors
• 2D and 3D CAD Drawings
• Hydraulic and Electrical Schematics
• Tooling Drawings and Assembly Guides
• Preventive Maintenance Schedule
• Bill of Materials (BOM)
• Spare Parts and Vendor Contact List
• Sample Reports and Output Files
• High-resolution Photos of Test Setup

Conclusion

Neometrix's Head Impact Test Rig delivers a robust, precisely instrumented solution for seat headrest impact testing. By combining proven electro-hydraulic mechanics with intelligent control software and rich data capture, the rig supports automotive R&D, production quality control, and regulatory certification under a single, repeatable test process.