(R) H-Point Machine and Design Tool Procedures and Specifications
|Publication Date:||1 February 2004|
The devices described in this document provide a method for a reliable layout and measurement of occupant seating compartments and/or seats. They are not to be construed as tools that measure or indicate occupant capabilities or comfort.
The devices are intended for applications at designated seating positions. They are not intended for use in defining or assessing temporary seating, such as folding jump seats.
When using the H-Point Machine (HPM), interactions can occur between adjacent seating positions (i.e., having an HPM installed at the center occupant position can change the results obtained for the outboard occupant position). Therefore, only one machine should be installed in a particular row of seats during each test.
General - This practice provides the specifications and procedures for using the H-Point machine (HPM) and the H-Point design tool (HPD). The HPM is a physical tool used to establish key reference points and measurements in a vehicle (see Figure 1). The HPD is a simplified CAD(Footnote 1) version of the HPM, which can be used in conjunction with the HPM, or independently during product design (see Figure 2).
For convenience and simplicity, many terms associated with H-Point devices use human body parts in their name. However, they should not be construed as measures that indicate occupant accommodation, human capabilities, or comfort. H-point devices do not represent the size or posture of any category of occupant.
H-Point devices are used (1) during vehicle design and development to establish interior reference points and dimensions for occupant packaging, (2) to validate the location of these key reference points and dimensions on physical properties during audits, and (3) to measure competitive vehicles during benchmarking. The procedures employed for each usage vary somewhat, and are handled separately in this document.
H-Point devices are also used for the design, audit, and benchmarking of seats. However, in these instances, the reference points and dimensions are defined relative to the seat structure and/or surface, rather than the vehicle's interior. The procedures for positioning the H-Point devices in seats are abridged, and do not require the use of the shoe tool or leg segments. The seat procedures will be addressed in subsequent revisions to this document.
Critical Reference Points - Several of the reference points established with an H-Point device are required for the subsequent positioning of other design devices, such as head contours, eyellipses, and reach curves. The most critical reference points(Footnote 2) established by an H-Point device are the H-Point, the H-Point travel path, the SgRP (seating reference point), the AHP (accelerator heel point), and the PRP (pedal reference point).
H-POINT - The H-Point is located on an H-Point device (HPM or HPD). However, when an H-Point device is properly positioned within a vehicle - either in CAD or in an actual physical property - the location of the H-Point relative to the vehicle is used as a vehicle reference point. If the seat is moved, the location of the H-Point within the vehicle is changed. Therefore, adjustable seats will have more than one H-Point location, while fixed seats will have only one H-Point location.
NOTE - H-Points are often referred to as hip points or hip pivot points. However, they do not represent the location of the human hip joint.
H-POINT TRAVEL PATH - All possible locations of the H-Point provided by the full range of seat adjustments (horizontal, vertical or rotational) for a given designated seating position.
SGRP (SEATING REFERENCE POINT) - A specific and unique H-Point defined for each designated seating position.
AHP (ACCELERATOR HEEL POINT) - A point located near the accelerator pedal on the depressed floor covering.
PRP (PEDAL REFERENCE POINT) - A point located on the lateral centerline of the accelerator pedal.
Footnote 1 - CAD is an acronym for computer-aided design. In a general sense, it has come to encompass any software system/approach to automotive design and development, and is often used to refer to CAE (computer-assisted engineering) and CAM (computer-assisted manufacturing) software systems as well.
Footnote 2 - See SAE J1100 for additional information on reference points, terms or dimensions used in this document.