1. Field of the Invention
The present invention relates generally to Anthropomorphic Test Devices (ATD) and, more particularly, to a flexible surrogate spine assembly for an ATD having an adjustable curvature that can be used to assess and predict injuries under crash, under body explosive, and aerospace ejection seat testing environments.
2. Description of the Related Art
Automotive, aviation, military, and other vehicle manufacturers conduct a wide variety of collision, ejection and under-body-blast (UBB) testing to measure the effects of an impact upon a vehicle and its occupants. Through the testing, a vehicle manufacturer gains valuable information that can be used to improve the impact worthiness of the vehicle.
Impact testing often involves the use of anthropomorphic test devices, better known as “crash test dummies.” During the testing, an operator places a crash test dummy inside a vehicle, and the vehicle undergoes a simulated collision, UBB, or ejection. The testing exposes the crash test dummy to high inertial loading, and sensors inside the crash test dummy, such as load cells, displacement sensors, accelerometers, pressure gauges, angle rate sensors, and the like, generate electrical signals of data corresponding to the loading. Cables or wires transmit these electrical signals of data to a data acquisition system (DAS) for subsequent processing. This data reveals information about the effects of the impact on the crash test dummy and can be correlated to the effects a similar impact would have on a human occupant.
In order to obtain more accurate test data, test engineers attempt to maximize what is known as the “biofidelity” of the crash test dummy. Biofidelity is a measure of how well the crash test dummy reacts like a human being in a vehicle impact test environment. A crash test dummy reacting as an actual human during a collision is said to have a high biofidelity. Accordingly, a crash test dummy having a high biofidelity will provide more accurate information from a collision test relative to the effect of the collision on a human being. Thus, ATD design engineers design crash test dummies with the proper anthropometry that reflects a total weight, center of gravity, mass moment of inertia and range of motion similar to that of a human body so as to increase the biofidelity of the crash test dummy.
However, it has been difficult to replicate the human spine for a crash test dummy. In particular, the human spine may have curvatures known as Kyphosis and Lordosis. Kyphosis is a curving of the spine that causes a bowing or rounding of the back, which leads to a hunchback or slouching posture. Lordosis is a curving of the spine that causes an abnormal forward or inward curvature of the spine in the lumbar region of a portion of the lumbar and cervical vertebral column. Two segments of the vertebral column, namely cervical and lumbar, are normally lordotic, that is, they are set in a curve that has its convexity anteriorly (the front) and concavity posteriorly (behind), in the context of human anatomy. As a result of the curvatures, Kyphosis and Lordosis angles may be measured. For example, a male may have a Kyphosis angle between 48-60° and a Lordosis angle is between 24-46°.
It is desirable to provide a surrogate spine for a crash test dummy that has improved biofidelity for the crash test dummy. It is also desirable to provide a surrogate spine for a crash test dummy that can replicate the Kyphosis and Lordosis angles. It is further desirable to provide a flexible surrogate spine for a crash test dummy. It is also desirable to provide a modular surrogate spine for a crash test dummy. It is still further desirable to provide a surrogate spine for a crash test dummy having spine and rib load cells. Therefore, there is a need in the art to provide a flexible, modular, surrogate spine for use in a crash test dummy so that biofidelity of the crash test dummy is improved.
Accordingly, the present invention is a flexible surrogate spine assembly for a crash test dummy. The flexible surrogate spine assembly includes a plurality of vertebra discs. The flexible surrogate spine assembly also includes a plurality of ligament joints disposed between the vertebra discs. The ligament joints have a joint element with varying joint angles that can replicate Kyphosis and Lordosis angles of a human spine.
In addition, the present invention is a crash test dummy including a body and a flexible surrogate spine assembly connected to the body. The flexible surrogate spine assembly includes flexible surrogate spine assembly comprising a plurality of vertebra segments with varying joint angles that can replicate Kyphosis and Lordosis angles of a human spine.
One advantage of the present invention is that a flexible surrogate spine assembly is provided for a crash test dummy. Another advantage of the present invention is that the flexible surrogate spine assembly for a crash test dummy has improved biofidelity for the crash test dummy. Yet another advantage of the present invention is that the flexible surrogate spine assembly for the crash test dummy represents a human spine with the ability to adjust the curvature for different postures. Still another advantage of the present invention is that the flexible surrogate spine assembly for the crash test dummy has the same number of vertebra discs as a human spine and the same number of ligament joints between the vertebra discs. A further advantage of the present invention is that the flexible surrogate spine assembly for a crash test dummy has modular vertebra segments that allow the spine curvature to be adjusted with different combinations of the modular vertebra segments. A still further advantage of the present invention is that the flexible surrogate spine assembly for a crash test dummy allows each vertebra disc to be replaced with transducers such as a spine load cell and rib load cell to measure the force and moment on the spine during a collision involving the crash test dummy.
Other features and advantages of the present invention will be readily appreciated, as the same becomes better understood, after reading the subsequent description taken in conjunction with the accompanying drawings.
Referring to the drawings and in particular
As illustrated in
The crash test dummy 12 also includes the flexible surrogate spine assembly 10, according to the present invention, having an upper end mounted to the head assembly 12 by a nodding block (not shown) and a nodding joint (not shown). The spine assembly 10 has a lower end extending into a torso area of the crash test dummy 12 and is connected to a spine mounting weldment (not shown) by an adapter assembly (not shown).
The torso area of the crash test dummy 12 includes a rib cage assembly 16 connected to the spine assembly 10. The crash test dummy 12 also has a pair of arm assemblies including a right arm assembly 18 and a left arm assembly 20, which are attached to the crash test dummy 12. The left arm assembly 20 includes a clavicle link (not shown), which connects a clavicle (not shown) to the top of the spine assembly 10. It should be appreciated that the right arm assembly 18 is constructed in a similar manner.
As illustrated in the
Referring to
Referring to
The joint element 40 has joint angles for different spine curvature. As illustrated in
With a combination of the four different angled ligament joints 34, different spine curvatures can be created as follows:
It should be appreciated that the overall spine length remains constant regardless of the combinations of ligament joint angles. It should also be appreciated that each ligament joint 34 has a constant height or same length at the neutral axis A. It should further be appreciated that more joint angles could be created if necessary by varying the angle of the upper and lower surfaces of the joint element 40 that allows the spine assembly to have different curvatures to present different human standing or sitting postures. It should still further be appreciated that the joint angles of the joint elements 40 allow for the spine assembly 10 to have an adjustable curvature.
As illustrated in
Referring to
Referring to
The rib cage assembly 16 also includes a flexible element 152 between the rib load cell 148 and the rib cage member 150. The rib cage member 150 has a rear portion connected to the flexible element 152 by a suitable mechanism such as an adhesive. The rib cage assembly 16 also includes a cartilage simulator (not shown) between the rib cage member 150 and sternum (not shown). It should be appreciated that the spine assembly 110 allows an interface with the rib cage assembly 16 and offers the capability to accommodate a load cell to measure the load transferred from each individual rib cage member 150 to the spine assembly 10.
The present invention has been described in an illustrative manner. It is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than of limitation.
Many modifications and variations of the present invention are possible in light of the above teachings. Therefore, the present invention may be practiced other than as specifically described.