Difficulty: expert

A Sensor Plan is a document that shows all stakeholders (Facility Managers, IT, Installation partner, …) where sensors and other hardware will be installed, taking into account sensor detection areas, obstructions etc.

In the course of a Workplace Analytics project, the Sensor Plan will provide concrete examples and bring forward discussion topics.

Means of Communication between all stakeholders

A Sensor plan can be used as means of communication between all stakeholders on

• Types of sensors and hardware to be installed (facility managers or technicians on site might not have been part of procurement process, so depending on for example headcount kind of sensor, you need to provide cabling/a hole in the ceiling; displays need cabling etc)

• Number of sensors and other hardware to be installed

• Installation location of sensors and hardware (for example where the hole needs to be in the ceiling compared to the detection area)

• Room numbers / names for each meeting room/bubble/work place/comfort area that will be covered by sensors

While this page focuses mainly on installation of occupancy & headcount sensors, check out Prepare your sensor plan (comfort sensors) for more information on how to create a similar plan for comfort sensors.

Requirements for Occupancy & Headcount Sensor Plan

Following information is required to set up a good sensor plan:

• Ceiling heights

• Latest floor plan with latest furniture drawings

• Superposition Reflected Ceiling Plan (RCP) file, which will provide information on ceiling height, type of ceiling and ideally also information on where light fixtures are installed, where to find HVAC, AC ducts etc (superposition = to reflect all elements on the ceiling that may occlude or interfere with the sensor detection area)

• Table design information sheets (material, length, depth, where are cable trays positioned, ...)

• Knowing heights of table partitioning: the higher, the more they will interrupt the detection area

• Materials of the walls (glass, fabric) , important for

  • rooms smaller than 4x4m and for displays (where can they be attached?)

  • pointgrab could see trough glass, so keep count area 0.5m away from glass

• if possible: videos or pictures that show the materials of the walls (glass, fabric), information on ceiling fabric, big obstructions like chandeliers or other

Parts of a good sensor plan

• Possible version control (version, date, contributor, changes made)

• Project context (any possible on-site information that is relevant to any of the stakeholders; for example a hospital context, trading floors with limited access etc)

• Workplace Hardware Scope: Number of sensors, hardware touch points

• Comments

• Sensor placement

  • (Needs to be based on latest floor plans! Ideally including latest furniture drawings)

  • Sensor plans of different floors, incl

    • Numbers of different sensors for each floor

    • For headcount and motion sensors for meeting rooms: based on the ceiling / installation heights, you can define the detection area (remember that the Device is always in the middle of the Detection Area, which is measured at ground level); see below chapter on Best Practices of Determining the Detection Area + following pages for more information:

      • Pointgrab Height ~ Detection Area: detection area is a rectangle

      • VergeSense Height ~ Detection Area: detection area is a rectangle

      • Xovis Height ~ Detection Area: detection area is a rectangle

      • Motion Tabs Height ~ Detection Area: detection area is an ellipse

    • For comfort sensors, see Prepare your sensor plan (comfort sensors) : zone covered per sensor (realize that a sensor only tracks the comfort in the spot of installation, so be mindful of not making the "covered zone" not too large. Best practice is not to group workplaces of which some are facing the sun in the morning with workplaces that get the afternoon sun)

  • Headcount installation direction: Sensors are displayed as circular icons on the floor plan, with an arrow pointing in their view direction (general convention is either pointing upward or to the right of the sensor plan).

Ideally, there are 3 parts to the Sensor Plan:

1. Sensor Detection Zone layout (shows the detection zones of each sensor, including stitching/detection area overlap): to be used to discuss which areas will be tracked
   
   

2. Sensor Installation layout (with measurements on 2 walls): to be used as installation instruction
   
   

3. (in case of headcount sensors) Area plan with all count areas (areas that need to be tracked): to be used as briefing for the consultant setting up the configuration (eg max 10 areas per Pointgrab; max 8 per Vergesense device)

   1. Assuming that the planner is the one that crops the image and provides the plan for upload in the headcount management tool: When extracting in CAD floor plan, it's possible to provide X,Y coordinates for sensor install in the headcount management tool

Open

Sensor Plans in different stages: Sensor Detection Zone layout (top) and Area plan with all count areas to be tracked (bottom)

Determining Detection Area: Best Practices

• Mind that the detection area is measured on floor level: any person standing on the edge of the detection area might not get picked up.

  → Avoid setting up count area at the edge of the detection area. It's a best practice to include 1.5.m coverage on all sides

Open

• For meeting rooms: Because of the above mentioned edge of the detection area & because you never know how a room might be used in future, it's best practice that the detection area should cover the whole room, even if that means adding an additional sensor to the room

• Specific for headcount sensors: 

  • If more than 1 sensor is used to cover an area, these will need to be "stitched" together in the software. For Pointgrab: Allow an overlap of 0.5m in the detection area of 2 sensors that lie side-by-side and need to be stitched.

  • Traffic line: 1 single sensor for 1 traffic line (this takes into account for CPU and calculations, otherwise accuracy will drop)

  • Tracking Workplaces through headcount sensors?

    • With Pointgrab: 1 single sensor can cover up to 10 count areas

    • With VergeSense: 1 single sensor can cover up to 8 count areas

  • Pointgrab can see trough glass, so keep count area 0.5m away from glass

Examples of sensor plans

This example shows "Sensor Detection Zone layout" (not yet highlighting the individual Workplace Areas that would be covered), differentiating between open spaces (pink) and closed spaces (green). This is not a must.

What is expected though, is to clearly show Headcount installation direction.

In the following example, the ceiling was very high and we needed to get creative.

Sensor plan of our own offices in the Netherlands

Examples of possible obstructions/sensor placement according to guidelines not 100% possible

Below list of examples of possible obstructions (where sensor placement according to guidelines is not 100% possible), is just to give you an idea of what you might run into.
Each kind of sensor comes with a set of installation guidelines that provide the Spacewell subscribed accuracy, but sometimes it's just not possible to follow them to the letter in all locations. Yet all stakeholders must understand that if the installation is not according to the guidelines, measurement accuracy will be impacted (which could lead to more false positives or false negatives).

These examples show how important it is to have an on-site-visit; or a lot of pictures or a walk through while on a call.

desks

• cable trays/bars under the table

concentration spaces

• covered with fabric

  • is there a table/something in another material, where the sensor would attach?

ceilings

• ceiling too high compared to max ceiling height for resp. sensor (need to think of other installation height, eg suspended cable trays)

• chandeliers or other obstructions hanging from the ceiling

• projector hanging from the ceiling

• HVAC tubes

• cable trays

• curved ceiling

• ceiling is divided into different parts/not flat

Edge cases

Exercise

Can you identify an attention point on the the example sensor plan of the second floor (with headcount sensors, motion sensors, comfort sensors and door counter sensors) ?

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