When Walking Into A Park, Where Do You Sit?

Video Link: https://youtu.be/Kuz_Yg70DJs

In New York City parks, there are 43 bench seats per acre. However the relationship of benches and where people sit has not been measured and studied thoroughly. In most circumstances, as William Whyte stated, “people tend to sit most where there are places to sit.” Does this hold true in public spaces when people are given choices about location, type, and orientation of benches? Behavioral cues of people sitting on benches can provide many valuable information not only on understanding people’s patterns in public spaces, but it will also help architects and planners to effectively allocate sitting placements.

In order to understand sitting preferences and patterns of park users, our group collected sample data on people using the bench- es. On May 4th, we dispatched and installed ultrasonic sensors
on to three benches and collected data on people sitting on the benches. With collected data, our group analyzed 1) the use rate of seats and 2)the use pattern in terms of time, location, and types of seats.

Our initial research provided that utilization rate of benches were similar despite location and design of the bench. However, occupancy pattern was more uniform for the bench that was located in the middle of the park. Based on our finding from sensor data, we were able to understand that location of the bench played

a critical role in occupancy pattern of the bench. When we incorporate qualitative analysis into our findings, it becomes clear that locations of the bench is important for both utilization rate and occupation pattern.

However, due to limited number of sample size and duration and also accounting for margin of error, the current research would serve as a prototype for further studies. Our initial analysis will pro- vide us a foundation for understanding people’s sitting behaviors in open/public spaces and allow us to improve our research methodology and approach. As mentioned, We will be able to further investigate on factors impacting the behavioral decision by broaden the scope and eliminating limitations we currently face for current project.

Xinyu Liu (Rainy)

Xinyu Liu is currently a M.S. Urban Planning first-year student in Columbia University Graduate School of Architecture, Planning, and Preservation and was before trained as a human geographer during her undergraduate in the Chinese University of Hong Kong.

Rainy has broad interest in urban planning: being especially interested in the political and social issues in urban planning, she is also enthusiastic about urban data and analytics, though being very prudent and critical in using them.

For more information, you may contact her at xl2803@columbia.edu. Any friendly discussion is welcomed.

 

When Walking Into A Park, Where Do You Sit?

Do you remember where did you sit last time when you walked into a park with all types of benches and chairs? Is there any specific reason why you sit on this bench, not the other ones? This is exactly what we hope to explore! Via our project in the Starlight Park, we would like to use the fancy technologies — sensors — to examine when and where do people sit and find out any pattern or predilection, if exists, of people deciding on the seats to take. Specifically, what types or settings of seats do people perfer and does this vary during the day? This will not only help us learn and understand people’s behavior, but will also facilitate designers and place-makers to create more attractive public spaces for our city in the future with more welcoming and favorable seats.

During our measurement, you are encouraged to enjoy your park and take your seats as usual. Sensors, which will be installed to some of the benches, are going to automatically sense your presence. Notice that only your presence and the length of that will be measured — we guarantee that none individual information nor privacy will be included in our measurement. No need to panic, and enjoy your stay!

Thanks for your understanding. If you have any question or concern about this project, you are invited to contact us directly through the following:

Kevin Kim (kk3296@columbia.edu)

Yuan Gao (yg2603@columbia.edu)

Xinyu Liu (xl2803@columbia.edu)

Visible Light Sensor – Photoresistor

Photo cell (CdS Photoresistor from Adafruit)

A very small light sensor. A photocell changes (also called a photodetector, photo resistor, CdS or photoconductive cell) resistance depending on the amount of light it is exposed to. These little sensors make great ambient light triggers (when light in the room turns on, do something).

Technical Description

CdS cells are little light sensors. As the squiggly face is exposed to more light, the resistance goes down. When its light, the resistance is about 5-10KΩ, when dark it goes up to 200KΩ.

Limitation

The linear relationship of the resistance and light level makes the sensor not very sensitive to changes in darken area, and also easily ‘max out’ where light is ample.

Skill

Noob (Basic)

Sample Sensor

Photo cell (CdS Photoresistor): https://www.adafruit.com/product/161.

GA1A1S202WP Log-Scale Analog Light Sensor: https://www.adafruit.com/product/1384.

Sample Exercise

https://learn.adafruit.com/photocells.

https://learn.adafruit.com/adafruit-ga1a12s202-log-scale-analog-light-sensor.

Ultrasonic Sensor

Ultrasonic Sonar Distance Sensor from Adafruit

Similar to dolphins’ echo-location ability, ultrasonic sensors are used to detect the distance between the object and the sensors. With this function, it is commonly used for automation, interactive art, and motion sensing.

Technical Description

A ultrasonic sensor consists of a transmitter and a receiver. The transmitters sends high-level signal at a certain frequency and the receiver detects whether there is a pulse signal back. The time duration from sending the signal to receiving it back multiplied by the sound speed can give us the distance between the sensor and the object being detected.

Limitation

Different devices may have distinct restrictions on the distance that can be measured with relatively high accuracy. Be careful when selecting a suitable one for you.

Skill

Rookie

Sample Sensors

Ultrasonic Distance Sensor: https://www.sparkfun.com/products/13959

Ultrasonic Sonar Distance Sensor: https://www.adafruit.com/product/3942.

Sample Exercise

https://www.instructables.com/id/Simple-Arduino-and-HC-SR04-Example/.

 

Laser Sensor

Time of Flight Distance Sensor from Adafruit

The sensor can detect the “time of flight” that is how much time the laser has taken to bounce back to the sensor, and in this way calculate the distance between the sensor and the detected object.

Technical Description

The sensor contains a very tiny invisible laser source and a matching sensor. After emitting the laser, it will measure the time it takes for the laser to bounce back to the sensor. The distance can be acquired by multiplying this time with the light speed.

Limitation

Since laser sensors generally use very narrow light source, it can only determine the distance of the object/surface directly in front of it. Meanwhile, there are also recommended distance range for each specific device.

Skill

Competent

Sample Sensors

SparkFun Distance Sensor https://www.sparkfun.com/products/14722.

Garmin LIDAR – Lite Optical Distance Sensor https://www.adafruit.com/product/4058

Sample Exercise

https://learn.adafruit.com/adafruit-vl53l0x-micro-lidar-distance-sensor-breakout.

Visible Light Sensor – RGB Sensor

RGB Color Sensor from Adafruit

RGB sensors are used to specifically detect the color of visible light. It provides a digital return of R, G, and B, and clear light sensing values.

Technical Description

RGB sensors consist of a color sensing photodiode whose resistance changes with lights of different spectrum. Some of these sensors are equipped with IR filter to minimize the IR component and therefore allows color measurements to be more accurate.

Limitation

There is no common limitation, but you need to be careful about the appropriate operating conditions for each device.

Skill

Competent

Sample Sensor

RGB Color Sensor with IR filter and White LED https://www.adafruit.com/product/1334.

Sparkfun RGB Light Sensor https://www.sparkfun.com/products/12829.

Sparkfun RGB and Gesture Sensor https://www.sparkfun.com/products/12787.

Sample Exercise

https://learn.adafruit.com/adafruit-color-sensors.

UV Sensor

Analog UV Light Sensor from Adafruit

UV sensors, as indicated by the name, are used to detect UV light and measure UV index.

Technical Description

Similar to the other light sensors, the essential component of the UV sensor is a photodiode, in this case a UV photodiode, which can sense the spectrum range of UVA and UVB. The analog signal of the output voltage indicate the UV index.

Some other UV sensors, however, are not “true” UV sensors but rather work by sensing the visible light and IR from the sun and then calculating the UV index. You may find a sample sensor below.

Limitation

The spectrum range a sensor is able to measure with accuracy may vary among different sensors. Select the device based on your need.

Skill

Competent

Sample Sensors

Analog UV Light Sensor Breakout https://www.adafruit.com/product/1918.

Sparkfun UV Light Sensor Breakout https://www.sparkfun.com/products/15089.

S1145 DIgital UV Index  / IR / Visible Light Sensor https://www.adafruit.com/product/1777.