Design Specifications for the Powered Shopping Cart Project

(Published 9/28/04)

1. The total cargo volumetric capacity must be greater than or equal to 9500 in³

2. The total cargo weight capacity must be greater than or equal to 225 lbs

3. Cart “footprint area” must be less than or equal to 28” x 60”

4. The powered cart must be able to climb a wheelchair ramp with a slope of 1:12 and cross a speed bump 4 inches high with a length between 1 and 3 feet.

5. The cart must have a user controlled forward operating speed on level ground between 0 and 4 m.p.h. Maximum forward speed must be “governed” to 4 mph both on level ground and descending a 1:12 slope. Maximum reverse speed must be governed to 2 m.p.h.

6. Design teams must demonstrate that the driver is protected from injury and the cart retains complete functionality (only cosmetic damage is allowed) after a 4 mph impact, with the cart in the fully loaded condition (225 pounds of cargo and a 250 pound driver). The details of the impact test will be specified by 10/25/04.

7. Design teams must demonstrate that their cart designs have forward and reverse operation and hand-controlled braking and steering systems that provide adequate maneuverability (for traveling through aisles and turning between aisles) and stability (in the worst case loading condition for a minimum radius turn at maximum speed) to safely operate in a simulated retail store “test course” which will be specified by 10/25/04.

8. Design teams must show through realistic simulations that the cart will be available for use for at least 10 hours out of a typical 12 hour peak shopping day (with the other 12 hours available for charging/refueling/maintenance) and must demonstrate features that prevent the cart from becoming inoperable due to running out of fuel/energy (must provide advance warning equivalent to at least 30 minutes of operation).

9. Design teams must demonstrate that their cart designs contain features that enhance safety during mounting and startup and when users intentionally or unintentionally dismount from the cart abruptly, including a kill switch mechanism and other features that ensure the device cannot be operated without an adult in the proper driving position. The details of this safety demonstration will be specified by 10/25/04.

10. Must meet all applicable government and industry standards and all existing state and federal regulations (including those for powered vehicles operating indoors and for consumer products).

Design Criteria for the Powered Shopping Cart Project

Most Important for evaluating designs

1. Should have a total projected manufacturing cost low enough to make the product marketable (based largely on the total recorded cost of the alpha prototype, including manufacturing and assembly labor costs).

2. Should be easy to operate

3. Should be reliable

4. Should withstand outdoor weather conditions such as rain and snow.

5. Should be stackable/compactable to minimize storage space

6. Noise created by the powered shopping cart during all modes of operation should be as low as possible.

Other Criteria

7. Should have acceptable aesthetics (so as to maintain dignity of users)

8. Should have a low weight (without operator or cargo)

9. Should be reasonably comfortable for the user

10. Should have a reverse signal

11. Should make the transfer of cargo from the cart to the user's vehicle reasonably easy

12. Should have key operated ignition and/or some other security features to control its use and protect the cart from theft

13. Should be comprised of commercially available materials and processes

14. Should have low operating costs / fuel costs

15. Should be designed to be easy to maintain / inspect / repair

Process Constraints for the Powered Shopping Cart Project

Deadlines and milestones

· A working alpha prototype must be demonstrated to the public on May 7, 2005

Manufacturability

· A detailed manufacturing plan must be developed that details how the product will be manufactured (in lots of 5000/yr) and that estimates the per unit production cost at that production volume.

· The material, material condition, manufacturing method, surface finish, and tolerances must be specified for every component and subassembly and justified based on Design for Manufacturing and Assembly principles

Environmental

· The design (and any fuels or power sources) must be evaluated for its total environmental impact, including concerns related to materials (recyclability, manufacturing waste, ...) and operation (emissions). Specifically, design teams must show through calculations and/or simulations the maximum H, CO and CO₂ emission levels for their designs over a 24 hour period (including a 12 hour shopping day and any recharging/refueling operations) and provide full disclosure of any foreseeable conditions (number of carts, size of retail store, ...) under which their cart design could cause a violation of the permissible exposure limits (PEL) for H, CO and CO₂ as defined by OSHA table 29 CFR 1910.1000.

Political

· A patent search must be completed and documented to identify any possible intellectual property issues and to identify existing patented ideas for devices that provide mobility assistance for the shopping experience.

Note: Safety and economic constraints are included in the product constraints.