Instrumentation & Measurement Magazine 23-6 - 34

Fig. 2. Phased development of the system.

be low cost to manufacture in order to successfully commercialize it.

System Overview and Design
The system was developed in three phases, shown in Fig. 2. It
comprises the mechanical hardware of the walkover platform,
the electronic module for data capture and analysis, and the
statistical interference engine.

Walkover Platform
The main concept of the design revolves around having a platform that can capture ground reaction forces that are produced
when cattle walk over it. The platform has four separate segments, sections A to D, as shown in Fig. 3. Each segment is
equipped with four load cells, installed in the four corners as
shown in Fig. 4. The platform can support at least 500 kg, as the
weight of the three most common dairy cattle breeds in New
Zealand is between 400 kg and 490 kg [2]. Each platform segment, which is 700 mm long, can be adjusted by ±50 mm to
accommodate varying stride lengths. The entire platform fits
within the standard width of a cattle race in a milking shed.
The overall height of the platform has been kept as low as possible so that the cattle do not have to raise their legs higher
than usual as this could alter the signals produced. Special
care is taken to ensure that there are no protruding bolts on

Fig. 4. (a) Top and (b) bottom view of a platform segment with four load cells.

the walking surface and no small crevices for stones or foreign
objects to accumulate. The platform can handle high-pressure wash downs twice a day. The load cells and electronic
hardware are enclosed to give a degree of waterproofing and
protection from direct high-pressure water.
The reference location for the measurements is the bottom
left corner centered on the load cell (Fig. 3). A 340 mm blanking
spacer was inserted before the first segment to fill in the gap
in the main frame of the platform. The spacer was placed at
the beginning rather than the end of the platform as it was observed that the cattle took a large stride when stepping up onto
the platform. This location therefore yields the lowest disturbance to the captured data.
The boxes housing the electrical circuit are mounted underneath the platform trays which protects them from direct
high-pressure water blasting during cleaning.

Signal Capture and Processing Hardware
Fig. 5 shows the functional blocks of the electronic hardware.
Each platform section has three generic function blocks; these
consist of four ASB1000 shear beam load cells (one in each
corner), a 24-bit four-channel sigma-delta ADC (AD7193) to interface the load cells and an ATmega328 microcontroller acting

Fig. 3. (a) Platform with 4 segments; (b) Cows walking over the lameness detection platform.
34	

IEEE Instrumentation & Measurement Magazine	

September 2020



Instrumentation & Measurement Magazine 23-6

Table of Contents for the Digital Edition of Instrumentation & Measurement Magazine 23-6

No label
Instrumentation & Measurement Magazine 23-6 - Cover1
Instrumentation & Measurement Magazine 23-6 - No label
Instrumentation & Measurement Magazine 23-6 - 2
Instrumentation & Measurement Magazine 23-6 - 3
Instrumentation & Measurement Magazine 23-6 - 4
Instrumentation & Measurement Magazine 23-6 - 5
Instrumentation & Measurement Magazine 23-6 - 6
Instrumentation & Measurement Magazine 23-6 - 7
Instrumentation & Measurement Magazine 23-6 - 8
Instrumentation & Measurement Magazine 23-6 - 9
Instrumentation & Measurement Magazine 23-6 - 10
Instrumentation & Measurement Magazine 23-6 - 11
Instrumentation & Measurement Magazine 23-6 - 12
Instrumentation & Measurement Magazine 23-6 - 13
Instrumentation & Measurement Magazine 23-6 - 14
Instrumentation & Measurement Magazine 23-6 - 15
Instrumentation & Measurement Magazine 23-6 - 16
Instrumentation & Measurement Magazine 23-6 - 17
Instrumentation & Measurement Magazine 23-6 - 18
Instrumentation & Measurement Magazine 23-6 - 19
Instrumentation & Measurement Magazine 23-6 - 20
Instrumentation & Measurement Magazine 23-6 - 21
Instrumentation & Measurement Magazine 23-6 - 22
Instrumentation & Measurement Magazine 23-6 - 23
Instrumentation & Measurement Magazine 23-6 - 24
Instrumentation & Measurement Magazine 23-6 - 25
Instrumentation & Measurement Magazine 23-6 - 26
Instrumentation & Measurement Magazine 23-6 - 27
Instrumentation & Measurement Magazine 23-6 - 28
Instrumentation & Measurement Magazine 23-6 - 29
Instrumentation & Measurement Magazine 23-6 - 30
Instrumentation & Measurement Magazine 23-6 - 31
Instrumentation & Measurement Magazine 23-6 - 32
Instrumentation & Measurement Magazine 23-6 - 33
Instrumentation & Measurement Magazine 23-6 - 34
Instrumentation & Measurement Magazine 23-6 - 35
Instrumentation & Measurement Magazine 23-6 - 36
Instrumentation & Measurement Magazine 23-6 - 37
Instrumentation & Measurement Magazine 23-6 - 38
Instrumentation & Measurement Magazine 23-6 - 39
Instrumentation & Measurement Magazine 23-6 - 40
Instrumentation & Measurement Magazine 23-6 - 41
Instrumentation & Measurement Magazine 23-6 - 42
Instrumentation & Measurement Magazine 23-6 - 43
Instrumentation & Measurement Magazine 23-6 - 44
Instrumentation & Measurement Magazine 23-6 - 45
Instrumentation & Measurement Magazine 23-6 - 46
Instrumentation & Measurement Magazine 23-6 - 47
https://www.nxtbook.com/allen/iamm/26-1
https://www.nxtbook.com/allen/iamm/25-9
https://www.nxtbook.com/allen/iamm/25-8
https://www.nxtbook.com/allen/iamm/25-7
https://www.nxtbook.com/allen/iamm/25-6
https://www.nxtbook.com/allen/iamm/25-5
https://www.nxtbook.com/allen/iamm/25-4
https://www.nxtbook.com/allen/iamm/25-3
https://www.nxtbook.com/allen/iamm/instrumentation-measurement-magazine-25-2
https://www.nxtbook.com/allen/iamm/25-1
https://www.nxtbook.com/allen/iamm/24-9
https://www.nxtbook.com/allen/iamm/24-7
https://www.nxtbook.com/allen/iamm/24-8
https://www.nxtbook.com/allen/iamm/24-6
https://www.nxtbook.com/allen/iamm/24-5
https://www.nxtbook.com/allen/iamm/24-4
https://www.nxtbook.com/allen/iamm/24-3
https://www.nxtbook.com/allen/iamm/24-2
https://www.nxtbook.com/allen/iamm/24-1
https://www.nxtbook.com/allen/iamm/23-9
https://www.nxtbook.com/allen/iamm/23-8
https://www.nxtbook.com/allen/iamm/23-6
https://www.nxtbook.com/allen/iamm/23-5
https://www.nxtbook.com/allen/iamm/23-2
https://www.nxtbook.com/allen/iamm/23-3
https://www.nxtbook.com/allen/iamm/23-4
https://www.nxtbookmedia.com