H-Point Machine (HPM-II) Specifications and Procedure for H-Point Determination—Auditing Vehicle Seats
J4002_201001
This Standard provides the specifications and procedures for using the H-point machine (HPM1) to audit vehicle seating positions. The HPM is a physical tool used to establish key reference points and measurements in a vehicle (see Figure 1 and Appendix A). The H-point design tool (HPD) is a simplified CAD2 version of the HPM, which can be used in conjunction with the HPM to take the optional measurements specified in this document, or used independently during product design (see Appendix D).
These H-point devices provide a method for reliable layout and measurement of occupant seating compartments and/or seats. This document specifies the procedures for installing the H-point machine (HPM) and using the HPM to audit (verify) key reference points and measurements in a vehicle.
The devices are intended for application at designated seating positions. They are not to be construed as tools that measure or indicate occupant capabilities or comfort. They are not intended for use in defining or assessing temporary seating, such as folding jump seats.
Rationale:
The procedures for auditing the seat are essentially unchanged from the previous version of this standard. The most significant change is that the Ball of Foot (BOF) of the shoe does not have to be on the pedal surface. The HPM-II shoe can contact the pedal at any point(s) on the bottom of the shoe. The term Pedal Reference Point (PRP) has been deleted (since the BOF may not be on the pedal) and replaced by a new term called the Ball of Foot Reference Point (BOFRP). The AHP to BOF distance was changed from 200 mm to 203 mm to be consistent with SAE J826, J1100:2009, and vehicle manufacturers around the world.
The following physical modifications were made to HPM-II. The flat part of the shoe bottom was extended from 200 to 203 mm. A new scale was added to the top of the shoe to aid in determining the pedal contact point. A new H-point divot was added to allow CMM point taking from above. The knee angle scale was recessed to improve its durability and reoriented to improve its readability. Several figures were revised to illustrate these changes.
The terms Pedal Plane and Pedal Plane Angle (PPA) have been replaced by Shoe Plane and Shoe Plane Angle (SPA). These new terms more accurately convey the meaning. SPA is a side view angle that is provided by the vehicle manufacturer.
Related Topics:
Leg
Head
Torso
Knee
Foot
Humidity
Hand
Seats and seating
Vehicle occupants
Also known as: SAE J 4002
SAE MOBILUS
Subscribers can view annotate, and download all of SAE's content.
Learn More »
