AS NZS ISO 7176.4:2011 pdf free download – Wheelchairs Part 4: Energy consumption of electric wheelchairs and scooters for determination of theoretical distance range.
NOTE Weights, such as sandbags or similar items, can be ackied to the body support system to supplement the mass of a human test driver and to adjust the location of the centre of mass. To determine the correct location of the centre of mass of a human driver, the weight distribution of the wheelchair with the seated driver (plus additional weights. if used) can be compared with the weight distribution of the wheelchair with the dummy fitted to the body support system as specified in ISO 7176-22.
d) Using the distance measuring device (5.3), measure the length of the centreline of the test track to the nearest multiple of 0,1 m.
e) Connect the energy consumption measurement apparatus (5.2) to the terminals of the battery set in a manner that will provide the required accuracy.
f) Fully charge the battery set in accordance with the manufacturer’s instructions at an ambient temperature of between 18 °C and 25 C.
g) Prior to the test, condition the wheelchair by maintaining it at a temperature between 18 °C and 25 °C for not less than 8 h.
NOTE Conditioning the wheelchair and charging the battery set can be done at the same lime.
h) Immediately after completing g), to warm up the wheelchair drive system. drive the wheelchair around the test track ten times in the clockwise direction then ten times in the anticlockwise direction, at the maximum speed practicable while staying within the confines of the track. Stop the wheelchair within 2 m of the starting position. Record the energy consumed during the twenty warm-up laps, and then reset the energy consumption measurement apparatus.
Prior to conducting the tests, it is recommended that practise tests be conducted to enable test personnel to develop the driving skills needed to conduct the tests effectively.
7 Test procedure
7.1 Continuous driving test
a) Immediately after completing the preparation specified in Clause 6, drive the wheelchair around the test track ten times, in either the clockwise or anti-clockwise direction, at the maximum speed practicable while staying within the confines of the track. Use the energy consumption measurement apparatus (5.2) to measure the electric energy consumed by the wheelchair while it is in motion. Stop the wheelchair within 2 m of the starting position.
If the wheelchair stops during the test due to a depleted battery set, measure and record the total distance it travelled, including the distance travelled in subclause 6 h).
NOTE The distance travelled is the number of whole laps the wheelchair travelled, multiplied by the length of the centreline of the track, plus any additional part of a lap it travelled, measured along the centreline of the track.
b) If the wheelchair did not stop in a) due to a depleted battery set, repeat a), but driving in the opposite direction around the track.
c) Record the total electrical energy consumed by the wheelchair, expressed in watt hours, as follows:
EXAMPLE For a specific energy consumption of 24,8 Wh/km and a total energy capacity of 1 020 Wh, R would be recorded as 41,1 km.
If the battery manufacturer declares the nominal energy capacity, then EBAT is the nominal energy capacity of each battery, declared for a discharge time of 5 h, multiplied by the number of batteries used to power the wheelchair. If the energy capacity is not declared for a discharge time of 5 h, use the energy capacity declared for the nearest shorter period. Otherwise, calculate EBAT using the following formula.