True Body Weight Ingress Egress Tester

True Body Weight Ingress Egress Tester is a unique machine that can be utilized to evaluate either a complete seating system or almost any of its components.  The evaluation criteria are usually visual and include wear patterns and general durability of the seat covering material, the foam, and the mechanical structure underneath.  Sometimes, it is even used to evaluate the durability of the occupant’s clothing!

Generally, this machine has 4 servo-electric motor-driven axis and 3 pneumatic functions.  These motions of the test dummy, relative to the test sample, include; in & out, right & left, up & down, rotation, free weight drop & recapture, and independent activation of the legs. Any or all of these motions can be performed concurrently and in any order.

The most important of these motions is probably the “free weight” feature.  This is when the dummy is free to float up & down with true body weight, which is adjustable from about 35Kg, up to about 100Kg.  This free-floating up & down motion is in addition to the up & down servo driven motion and is functional only when the pneumatic latch pin is retracted.  When floating, under true body weight, the rotation and leg activation features are still available.  This allows for very life like programming of motion sequences.

Unlike a robot that uses a load cell to measure load, true body weight includes the dynamic effect of inertia.  A robot does not include this element.  Any ingress/egress test is a test in motion, and anytime there is motion – there is inertia.  Leaving out this important consideration changes the basic nature of the test, and quite possibly the results.

Test Principle: 

The test frequency, amplitude, and number of cycles can be set. The machine automatically stops when the set number of cycles is reached. The test verifies the fatigue life of the seat frame, foam, and fabric. Vibration tests are conducted at a frequency of 100 cycles per minute, with the seat cushion undergoing 100,000 cycles and the backrest 50,000 cycles. After the test, the samples should show no abnormalities; the seat frame should have no cracks, the foam should not be deformed, and the fabric and padding should not be damaged. The H-point variation should be within the rated range.

Operating Procedure and Parameters:

1. Prepare a 3D dummy model indenter. The 3D dummy model should conform to the 50% scale of the SAE J826-2002 standard. 1

Wrap the pressure head with a 12mm layer of foam and denim. Place appropriate weights on the pressure head to maintain a weightof 44.5KG.

2. fix the seat assembly on the simulated human body entry/exit test bench. Adjust the seat to the designed position and simulate the operation of a robot programmed for human body entry/exit:

①、The pessure head slides horizontally into the seat, sinking approximately 25mm into the seat cushion and backrest edges. The head rotates 30 degrees so that the inner rear part of the pressure head enters first.

② The Pressure head continues to enter until its center line aligns with the seat center line.

③ The Pressure head creeps to stabilize within the seat.

4 The Pressure head sinks into the seat until the load reaches 445N.

5 The Pressure head creeps against the backrest at approximately 30 degrees with a 445N load.

⑥ The Pressure head remains in the seat with a 445N load until it is halfway out of the seat.

⑦ Once the pressure head is halfway out of the seat, it slides along the seat cushion edges. A significant indentation occurs on the seat edges as the pressure head moves out.

3. Experimental frequency: 4.5 times/min,

4. Number of experiments: 15.000 simulated human body entry and exit experiments.