2011 Tshwane University of Technology – AIR-BOT

The TUT submission by Izak Nel, Alfred Barnard, Coenraad Prinsloo and Christiaan Oosthuizen came a close second in the 2011 PneuDrive Challenge. Their design investigated the distribution of food and beverages on airlines in South Africa, with their research noting that a local airline company served over 1.4 million meals a year.
With only rudimentary and manual services in place, the TUT team observed that the airline service industry in general faces massive risk due to the losses of food and beverage stock, revenue and time.
Consider some of the following basic inefficiencies:
1. Ineffective and inaccurate stock records – handwritten notes and stock sheets could get lost, torn or misinterpreted.
2. No intelligent control systems currently exist to continually monitor stock levels.
3. Absence of a system that monitors a cash transaction and provides confirmation of correct returns.
4. Time of staff is not efficient because all sales have to be manually logged and calculated.
Recognising that there is no existing solution to the above inefficiencies in the “airline industry” is interesting. Their solution of a mechanical process to electronically monitor and distribute stock is "out of the box" thinking that has attracted some noteworthy analysis and comment.

Competing Students: Izak Nel, Alfred Barnard, Coenraad Prinsloo and Christiaan Oosthuizen.

Click here to download a summary of the design.

The Environment

Local airline industry.

The Problem

The root of the problem with the existing approach to the supply of airline food and beverage items is the human element. Consider the following theoretical example to illustrate the extent of possible operational losses:
    1 400 000 meals served a year;
    Assuming an average value of an airline meal: R 30
    = R 42,000,000

    Assuming a loss of just 5% on this potential turnover due to some of the factors     mentioned above:
    = R 2,100,000 loss.

  A substantial figure for any business.

The Proposed Solution

An automated solution that will reduce possible compromises related to the control and distribution of stock, and allow cabin staff to focus on more technical and safety related duties.

The Market

The target market of the AIR-BOT will be any Airline Company that has the need to reduce the time required to serve food and beverage items, increase the sale thereof and improve on stock control.

How It Improves on the Current System

No current solution exists for the automated supply and control of food and beverages in the SA Airline industry.

The Cost

The design is an estimated R 670,000.
This amount excludes on-site assembly and installation costs.

Unique Features

First automated system that:
1. Incorporates actuators to dispense food and beverage items on an airplane.
2. Moves under its own power.
3. Offers automatic stock control records.

SEW Eurodrive’s Movitrans® product was selected for the electrical distribution, some of the main design reasons being:
• Provides electrical power to the AIR-BOT for the PLC and the drive-system by means of a contactless energy transfer system.
• Wherever the tracks are, the AIR-BOT can move about untethered and serve passengers
• No direct wiring from a main power source is required which results in a clean and neat operating system in an environment where wiring and connections would be unacceptable.
• Safety: No exposed high voltage connections and wiring. Power transfer is done through electromagnetic induction keeping passengers isolated from the electricity that powers the trolley.
Other alternatives and trade-offs were evaluated, and are contained in the original design report.

The design presents the possibility of a fully autonomous serving robot trolley that will move on its own by means of a motorised drive system. Two centrally mounted drive wheels are proposed with an allowance for the trolley to turn on its own axis, thereby making the trolley extremely manoeuvrable

In most applications mounting, size and weight of equipment is not very important. However, because of the proposed operating environment (on an aircraft), careful consideration had to be made as to where all the components were going to be stored or mounted in the AIR-BOT.

List of equipment mounted on the inside of the AIR-BOT:
• FESTO PLC chassis plate with I/O, valves and control equipment.
• FESTO air vessel, air regulation / purification equipment and pressure booster
• SEW drive motors and drive train system
• SEW MOVITRANS® mobile converter
• Two SEW inverters supplying the drive motors.

3.3 Distribution: Food and Beverage Dispensing System

Although the original design report goes into detailed descriptions of the dispensing mechanism, for the purposes of this article it is sufficient to describe the dispensing system as a system made up of interchangeable, modular and reusable magazines that are stocked at a factory or a specific packing and distribution point. The design allows for the majority of the food and beverage items to be dispensed from the top of the trolley in an easy to reach area, and not the side as in conventional trolleys. This makes using and operating the trolley much easier than conventional push trolleys which require constant bending and standing to locate and distribute items. It was decided that FESTO’s rodless linear actuator, mounted on the side of each magazine, would be the ideal mechanism for lifting items into the dispensing area.

SLG-12:Linear drive

Raises lifting platforms in magazine dispensers.

GRLA-M3 1-way control valve

Locks SLG Drives in place to inhibit slumping of the lifting system.

U-M5 Silencer

Suppresses the sound of pneumatic action for customer convenience.

QSM-M5-3 Push-in fitting

Connects the pneumatic tubing to the input ports of the SLG Actuator.

CPX-MPA

This is the PLC unit including all valves, I/O modules and terminals.

FED-501

External touch display to will be used for communication between the AIR-BOT and the user.

FEC-KBG8

Communication cable for external display.

FEDZ-PC

Programming Cable.

DPA-40-10

Air pressure booster.

CRVZS-5

Air vessel 5L.

MSB-4

Air regulator / filter.

B-3/8

Air vessel water drainage plug.

D-1/2l-1A

Air vessel outlet / inlet reducer.

D-1/4l-1/2A

Air vessel outlet / inlet reducer.

PUN-10x1.5-SG-2,4-BL-1/4

Tube to be used in air supply up to regulator (Can handle up to 15bar).

PAN-8X1,25-BL

Tube to be used between drives and valves.

THM10E015-009-000-2

Flat pick-up with UL approval, IP65, 1.5kW/cdf 100% T (periphery 40 C, up to 6 m cable and Han 4/2 plug connector.

TPM12B030-ENE-5A2-2

Connection of 1 to 2 flat THM10E pick-ups, IP65, 3kW/ED 100%.

TPS10A040-NF0-503-1

Built-in unit, IP 20, 4kW cdf 100%, Integrated fan, connection 380 – 500 V AC +/- 10%.

TAS10A040-N06-4x1-1

Built-in IP20, 4 kW cdf 100%, Output 60 A/25 kHz, incl. gyrator, transformer, without compensation capacitors.

NF014-503

Built-in unit, IP 20, 14 A, used for TPS10A040

TCS10A-008-040-0

Compensation capacitor, capacitor 4μF, with setscrew for installation in TAS 10 A, Reactance at 25 kHz = 1.6 ohm

TLS10E-016-01-1

Conductor loop for flat pick-ups, MF litz wires, floor routing, cable cross section 16 mm², outer diameter 10.9 mm, reduced transmission power.

TLS10E-006-06-1

Power supply cable from supply cabinet to energy transmission line, fine litz wires, routing in cable duct, cable cross section 2x3x6 mm², outer diameter 20.5mm.

TVS10A-E08-000-1

Stationary connection components(wiring box), to connect MF cables, flange plate 2 x M32 / 4 x M25.

TCS10A-E06-090-1

Stationary connection components, to connect MF cables, capacitive reactance at 25 kHz = 7.1 ohm, flange plate 4 x M25.

DFR63M6/BR

AC Motor

MDX61B005-5A3-4-00

Frequency inverter. This unit is used to invert the DC supply to usably AC and vary frequency for speed control.