Assistive Driving Aids for the Disabled

ANTON J. REICHENBERGER, B.S.M.E.


For the last five years the Veterans Administration Prosthetics Center has conducted annual compliance tests of adaptive automotive hand controls in accordance with VA standards and specifications. These yearly tests result in a list of accepted manufacturers who supply VA beneficiaries with a variety of "add-on" control hardware for their personal motor vehicles. Since there currently are no other specifications to assure the availability of mechanical brake-accelerator hand-control systems with a minimum level of safety and quality, compliance with VA requirements has become an indicator of acceptance by many other organizations. We are informed that the Department of Transportation, through the National Highway Traffic Safety Administration, is viewing the possibility of national standards for adaptive automotive hand controls. Federal motor vehicle safety standards in this area would be of tremendous value to all motorists, handicapped and nonhandicapped alike. Meanwhile, we continue to serve our clients in need of adaptive automotive equipment through the guidelines developed by the Veterans Administration.

Conventional Control Systems

Conventional mechanical brake-accelerator hand-control systems for passenger motor vehicles are grouped into three types, i.e., push-pull, push-right angle pull, or push-twist. These distinctly different input requirements on the control handle give handicapped drivers with near normal strength and mobility of both upper extremities some choice in driving a motor vehicle. It is assumed that the motor vehicle is equipped with power brakes and power steering. Although most "add-on" hand-control systems could be installed for right-hand use, maximum driving comfort is usually achieved when the brake-accelerator control is left-hand operated. The brake-accelerator control motions for "add-on" hand controls are:

  1. Push-Pull Control System
    To apply brakes, the driver pushes the control handle in the forward direction, parallel to the steering column. Actuation of the accelerator is achieved by pulling the same lever in the opposite direction, toward the driver (Figure 1. ).
  2. Push-Right Angle Pull Control System
    To apply brakes, the driver pushes the control handle in the forward direction, parallel to the steering column. The accelerator is actuated by pulling the same lever in the downward direction, toward the driver's lap (Figure 2. ).
  3. Push-Twist Control System
    To apply brakes, the driver pushes the control handle in the forward direction, parallel to the steering column. The accelerator is actuated by counterclockwise rotation of the handgrip (Figure 3. ).

We note that all brake control motions are similar, i.e., in the forward direction. Throttle control requires a pull, a right-angle pull, or a twist motion. The April 1979 list of adaptive automotive hand-control manufacturers in compliance with VA requirements will be found in the Appendix.

Wheelchair Vans

For handicapped drivers without sufficient strength to make the wheelchair-car-wheelchair transfer, and for those who for any reason use an electric wheelchair, specially modified vans are available. These vehicles are normally equipped with power lifts, wheelchair tie-down devices, and mechanical hand controls. Wheelchair lifts operate at either the right side or the rear doors of the van, and most use an electric motor as either a direct source of power for the lift or as a source of power for a hydraulic pump, which in turn is used to power the lift.

The Veterans Administration has promulgated standards and specifications for automatic wheelchair-lift systems for passenger motor vehicles. Compliance tests of a wide variety of commercially available wheelchair lifts are planned for the fall of 1979. Consequently, we expect to gain a list of wheelchair-lift manufacturers who have met the minimum requirements for safety and quality of automotive wheelchair-lift systems.

The general mode of operation of a conventional van is to approach the vehicle from the curb side if it is a side loader or from the rear if it is a rear loader, operate the control system to open the doors, bring the wheelchair lift to curb or street level, drive the wheelchair into position on the lift, actuate the lift-ascent control, enter the van by propelling the chair off the lift platform and into the driver's position, bring the lift back in place and close the doors, and lock the wheelchair in the driving position.

Several years ago the VA Prosthetics Center initiated an evaluation of a number of specially adapted automotive vans for wheelchair users, in compliance with Public Law 93-538. There were eight sufficiently different van configurations at the start of the evaluation program to warrant individual comparative analysis of their relative merits. The purpose of the van evaluation program is summarized as follows:

  1. To obtain experience on the relative merits of all of the available van systems with particular respect to access systems, driving control, roadability, and convenience of various features for individual or family use.
  2. To develop government standards of safety, quality, and durability governing the purchase of vans by veterans under beneficiary entitlements.
  3. To clarify prescription indications for various types of vans.
  4. To enable qualified veterans to learn to drive and take licensing tests, and to give them experience in the use of a variety of van configurations.
  5. To help veterans select the most appropriate vehicle for themselves.

The following descriptions offer a few typical examples of specially adapted vans used in the VAPC evaluation program.

Drivemaster Van (Figure 4. )

Access to the vehicle is provided by a side-loading lift which rotates approximately 180 deg. The lift is actuated, as are the others, from outside the van and from inside the van. The lift is stored in the cargo space of the van. The vehicle is controlled by conventional mechanical brake-accelerator hand controls.

Royce Van (Figure 5. )

This van is also a side loader whose lift is a structural part of the van. In effect it combines both ramp and lift. The user lowers the lift, drives his wheelchair onto it, raises the lift to a horizontal position and rolls aboard the van, from where he raises the lift completely and, in effect, closes the "side door." The lift platform does not occupy cargo space, but the motor and housing do. One unique feature of this van is the driving seat into which the user may transfer from his own wheelchair.

Motorette Van (Figure 6. )

This van features a rear-loading wheelchair lift, and is controlled by conventional mechanical brake-accelerator hand controls. We are aware that the Motorette Corporation is no longer in the van conversion business.

Special Control Systems

Severely handicapped drivers whose residuals do not permit them to operate conventional hand controls may require a special control system to operate a personal motor vehicle. There are several highly experimental and developmental control systems in our current automotive evaluation program. These servo-controlled brake-accelerator or brake-accelerator-steering systems represent the most advanced approach in finding adequate motor-vehicle control systems for some of our disabled drivers. Typical examples of experimental servo systems installed in passenger motor vehicles are:

  1. Scott Van (Figure 7. )
    This van is quite different from the three previously shown in that it represents the archetype of a vehicle modified especially for the handicapped. The other vehicles were modified by the addition of hand controls and a wheelchair lift system. The Scott Van is of the rear-loading type, and its most unique feature is the joystick-type servo control. Operation of the ignition and all accessories, including lift and rear doors, is accomplished by actuating push buttons mounted on a panel facing the driver. Acceleration is accomplished by pushing the joystick forward, and braking is accomplished by pulling it backward. Rotating the small wheel steers the vehicle. A specially designed electric wheelchair is part of the motor vehicle.
  2. CCI Harden Controls (Figure 8. )
    The brake-accelerator servo control handle can be installed either near the steering wheel, similar to a conventional mechanical hand control, or on the side of the left door; the choice remains the preference of the handicapped driver. To apply brakes, the control handle is pushed in the forward direction. Actuation of the accelerator is achieved by pulling the control handle in the opposite direction, toward the driver.
  3. Renault-Saviem (Figure 9. )
    The motor vehicle features a force-sensitive servo-operated brake-accelerator-steering control system. The control handle remains in a fixed position, depending on minimal force inputs to operate brakes and accelerator, as well as vehicle steering. To apply brakes, a small pushing force is exerted on the control handle in the forward direction. Actuation of the accelerator is achieved by applying an equally small pulling force on the control handle in the opposite direction.

Motor-vehicle steering is achieved by exerting a minimal force to either the left or right side of the control handle.

Nearly all power-augmented motor-vehicle control systems are highly experimental, and few are commercially available. Effort toward future progress in the area of servo-operated motor-vehicle control systems appears to be modest, and solutions to many complex problems are needed. An optimistic projection should include some future participation by the automotive industry. Frankly, much remains to be done to improve mobility for self-sufficient handicapped drivers.

Appendix

Adaptive Automotive Hand-Control Manufacturers in Compliance with VA Requirements April 1979

Blatnick Precision Controls,
Inc. 1523 Cota Ave.
Long Beach, CA 90813 (213) 436-3275

Manufacturing & Production Services
4664 Mercury St.
San Diego, CA 92111 (714) 292-1423

Drive-Master Corp.
16 Andrews Drive W.
Patterson, NJ 07424 (201) 785-2204

Ferguson Auto Service
1112 N. SheppardSt.
Richmond, VA 23230 (804) 358-0800

Gresham Driving Aids
P.O. Box 405
Wixom, MI 48096 (313)624-1533

Handicaps, Inc.
4335. S. Santa Fe Dr.
Englewood, CO 80110 (303) 781-2062

Hughes Hand Driving Controls, Inc.
P.O. Box 275
Lexington, MO 64067 (816) 259-3681

Kroepke Kontrols, Inc.
104 Hawkins St.
Bronx, NY 10464 (212) 885-1547

Mobility Products and Design, Inc.
709 Kentucky St.
Vallejo, CA 94590 (707) 642-8967

Nelson Medical Products
5690 Sarah Ave.
Sarasota, FL 33583 (813) 924-2058

Smith's Hand Control
1420 Brookhaven Dr.
Southhaven, MS 38671 (601) 393-0540

Trujillo Industries
5040 Firestone Blvd.
South Gate, CA 90280 (213) 564-7943 (Manufactures steering assists only)

Wells-Engberg
Co. P.O. Box 6388
Rockford, IL 61125 (815) 874-6400

Wright-Way Inc.
P.O. Box 40907
Garland, TX 75404 (214) 278-2676