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Fig. 8 Misura della potenza attiva nel giorno 17 Dicembre 2018, con sistema OTOMO attivo /
Measurement of active power on December 17, 2018, with OTOMO system in action
research was the Panzeri Carlo Srl and it
is from this collaboration that the first OTOMO
Enabled device was born, that is the Jackie IoT
lamp 10 , which integrates sensors of lighting
and temperature inside, and that exchanges
information with the other control system
nodes. The Jackie lamp has become a node
of IoT interaction, thus being transformed
into a sensor capable of interacting with the
surrounding environment.
The OTOMO system developed in the research
currently offers three different modes of light
control:
• The manual control of the system, through
a simple interface on the smartphone
or through physical buttons to help switch
on/off, or to adjust the lighting system
and selectively control each part.
• The automatic lighting control through
a brightness sensor associated with an
environment and to which several lighting
devices connected through a DALI 11 protocol
refer. If the building is very large, the system
supports the control of multiple rooms,
each equipped with its own light sensor.
The brightness and room temperature sensors
can be mounted on the ceiling or integrated
into furnishing objects or within the task light.
The data measured by the sensor can be
displayed by the app in real time, as shown
in Figure 1.
• The automatic lighting control by
implementing an advanced circadian function
in which the colour temperature of the
lighting fixtures is changed over the course
of the day, following the behaviour of natural
light. The colour temperature variation scheme
is stored inside the control device, but the
user can always access a manual control
of the colour temperature and lighting level
through the app on the smartphone (Figure 2).
Laboratory tests
The system’s ability to regulate the lighting has
been evaluated in a controlled environment
that simulates a real office installation.
For this purpose, we designed and implemented
a test facility set-up, apt to verify the system’s
functionality in reference to two possible real
operating conditions. The first was the function
of maintaining a constant level of illumination,
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fixed during the configuration phase of the
system, in accordance with the visual task that
the occupants of the space would be called
to perform during the working day. The second
was the circadian function, in which the system
changed the correlated colour temperature (CCT)
during the working day, for example from 9:00
to 18:00, in order to create an environment
that is more comfortable for the users and
that would also favour the normal phasing
of the circadian rhythm, as occurring in nature.
The set-up facility created in the laboratory
was realized by means of OTOMO devices
in combined use with the lighting equipment
supplied by Eelectron and Panzeri, in order to
have all the necessary elements for the testing
of the two functions previously described.
The test environment was implemented inside
the environmental testing room of the Lab.
Luce of the Politecnico di Milano, which
is equipped with an American structure
designed to host temporary lighting systems
to be tested; the test included also the feed-
back of users who experienced some specifically
designed lighting conditions (Figure 3).
The lighting set-up used for the tests was made
up by two dynamic white LED lighting fixtures
of 3F Filippi production, equipped with two
channels controlled by DALI protocol. The first
channel emitted warm white light at 2884K
correlated colour temperature and Ra=84, while
the second emitted cold white light at 7507K
correlated colour temperature and Ra=88.
We made the measurements placing the
measuring instrument under the luminaire
in a perpendicular direction to the emitting
surface. We waited a period of 15 minutes
so that the devices would reach the steady state
before proceeding with the measurement.
The installed control system was composed
of the following elements: the DALI-BLE module,
the brightness and temperature sensor ceiling
module with the possibility of manual control
of the system and the Jackie lamp with
integrated brightness sensor.
The luminaires were equipped with laminated
aluminium screens to limit the glare, and were
therefore suitable for installation in an office
with video terminals. The installation height
of the luminaire was 2.80m, while the height
of the worktop was 2.07m. The Jackie lamp
was placed at 1.20m from the floor. The worktop
was made of two desks placed side by side
under the lighting fixtures: one of the desks
was equipped with a task light to increase
the lighting levels on the visual task, if
necessary. The task light was in this case
the Jackie lamp, which has a built-in lighting
and temperature sensor of the control system.
The measuring instruments used were:
Yokogawa WT 110 wattmeter, Fluke 45
multimeter, Minolta T-1H and CL500A.
We conducted the first tests in the constant
lighting mode. Once a threshold of 300 lux
was set, we proceeded to measure the trend
of illuminances and the electric power absorbed
due to the equipment and the control system.
The measurement was conducted with a weak
contribution of natural light coming from the
laboratory’s windows, which could be darkened
with black all covering curtains. At the
beginning of the recording, the contribution
of natural light measured at the Jackie lamp
sensor, turned out to be less than 20 lux.
In this configuration it was possible to measure
the response of the control system for
a workstation away from the windows.
Figure 4 shows the results of the recorded
measurements, from which it can be deduced
that the system was able to accurately control
the level of illuminance on the visual task.
The estimated difference between the
positioning of a sensor on the table (visual task)
or above it of about 72 cm was approximately
22%. That is, the illuminance value was
overestimated by about 22%, but an appropriate
choice of the threshold value would compensate
for this offset maximizing the savings.
The test was performed by comparing the
measurements provided by the control system
with those from a lux meter with high accuracy
placed on the desk.
To evaluate the stability of the system
in keeping the lighting level constant,
as environmental conditions changed, we
also used a luminous double ramp disturbance
signal able to act on the Jackie lamp sensor.
The behaviour of the system was recorded
as a function of time and the results of the
measurements are shown in Figure 5.
The system responded so as not to trigger
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Fig. 9 Misura della potenza attiva nel giorno 16
Gennaio 2019, con sistema OTOMO non attivo /
Measurement of active power on January 16,
2019, with OTOMO system inactive