Consistent: The Four State Turtle

Elements

→ threshold ultrasonic sensor

→ flip-flop brick

→ Sequential Logic Circuits

While researching animal behaviors, I found the variations of threat response among organisms very interesting. It has been observed that animals have a set of basic responses to danger. I believe that Braitenberg’s four-state turtle approach can provide some useful insight into an animal’s response to a perceived danger. How can the implementation of simple memory affect the behavior of organisms encountering a threat? Ruben Vale, Dominic Evans, and Tiago Branco approach a similar issue in their article, “A Behavioral Essay for Investigating the Role of Spatial Memory During Instinctive Defense in Mice”. They look to observe how memory, environment, and defense mechanisms within mice interact (1). In their experiments they found that as the mice who successfully found their way out of one environment had a higher probability of success after being moved to another environment (Vale, Evans, Tiago 4). In addition to this finding, they also discovered that as the trials continued mice who worked their way through multiple environments saw a gradual increase in their probability of escape and decrease in time it took to achieve (Vale, Evans, Tiago 4). Vale, Evans, and Tiago’s work posits an interesting relation between memory and action however, I wonder how this relationship will change the behavior of Braitenberg’s vehicles. Robots inspired by nature are nothing new. Tools such as Logo, a programming language developed in the 1960s, helped popularize the nature inspired “floor turtle” aimed to teach children rudimentary geometry by utilizing its ability to move and turn (Resnick 66). Braitenberg’s vehicles are similarly inspired by the organic movement of animals found in nature. By following his approach we can explore the relation between memory and defense. By using Mims’s layout of sequential circuits, as found in “Getting Started with Electronics”, we can determine the logic required to construct a program that utilizes the microbit’s memory. This isolated task is relatively simple and can be easily implemented.

In order to create an “animal” that responds to an outside threat I will use the micro:bit’s ultrasonic sensor to gage the distance of objects. If the distance threshold is breached the state of the vehicle will change i.e., it will employ a defense mechanism. However, by utilizing micro:bit’s memory I will save the previous state and allow this boolean value to act as a clock. The clock mechanism can be seen above in Mim’s diagram. Its activation will lead to variation in defense responses.

Braitenberg’s creatures each embody particular behaviors observed in the nature world. His focus on behavior and dedication to the “constructionist approach” highlight their bio-inspired logic and hardware design (Hogg, Martin, Resnick 1). Similar to the brain’s nervous system, Braitenberg’s vehicles receive and respond to signals from the surrounding environment. Therefore, a penultimate goal I’d like to set for myself if to construct a direct connection between sensor and motors using a sequential logic circuit. However, I am not familiar with this circuit and its affordances therefore I will keep it as a “reach” goal (or a goal that I will strive for but may not achieve).

Part A: 4-State Turtle

Changes motor rotation with button A

Part B: Threat Response

Changes behavior with the activation of distance threshold in conjunction with memory of past state

Part C: Sequential Circuit

Construct sequential circuit

Resources:

Mitchel Resnick. “Behavior Construction Kits”.

Forrest M. Mims, III. “Getting Started in Electronics”.

David W. Hogg, Fred Martin, Mitchel Resnick. “Braitenberg Creatures”.

Ruben Vale, Dominic Evans, Tiago Branco. “A Behavioral Essay for Investigating the Role of Spatial Memory During Instinctive Defense in Mice”. Journal of Visualized Experiments. Vol. 137 DOI: 10.3791/56988