The Animatronic Robotic Hand

A new way to pursue the "Rubber Hand Illusion"

Capturing the subject's movements

The first function that our device needs to pursue is detecting the movements of all fingers belonging to the person wearing the control glove; to do this, Flex Sensors are used: Flex Sensors are particular kinds of potentiometers which are able to capture the displacements of a component. In our case, we have five Flex Sensors placed on a control glove, one over every finger; all these sensors are then connected to the PCB by means of a cable containing all their electrical wires. Also, the control glove chosen by us has an average-large size, and it is made in an elastic material, so that most people can be able to wear it.

Control Glove

PCB

The dedicated design of the PCB ensures the information flow and the power supply of the device. The flex sensors have a working principle of a potentiometer. Each of them is connected via the determined pin header to the PCB. To be able to gather information, there is a voltage divider structure on the PCB. With the acquired information the micro controller is able to control the connected servomotors. For rapidity and precision an external clock is used for the microcontroller. The PCB is powered by an external power supply. As the servos run with a voltage of 6V in order to obtain higher speed and the microcontroller runs with 5V, the PCB features two power circuits which are realized by using different voltage regulators. There are several programs running on the microcontroller in order to conduct different tests. For future needs the program structure might be changed or expanded. Therefore the USB interface guarantees an easy change of programs on the microcontroller. Nevertheless there is still the possibility of using an in-system programmer, as you need the ISP interface anyway to burn the boot loader on the microcontroller. All external modules like the LCD or the board containing the buttons, are connected via pin headers and can be removed or replaced easily. The LCD provides the user of the device with necessary information about the program, while the buttons are used to switch between programs or to adjust a parameter that is used in a program.

Schematics PCB PCB_print PCB_parts

We report in the table below the list of the components that have been put on our PCB, with a reference number recalling the image shown in the series above:

Position

Functionality

Part Name

Package

Value

Quantity

1

Microcontroller

ATMEGA328P-AU

TQFP


1

2

USB to UART adapter chip

FT232RL

SSOP


1

3

Clock

FOXSDLF/160-20


16MHz

1

4

Voltage Regulator

NJM7806DL1A-TE1

TO-252

6V

2

5

Voltage Regulator

NCP1117ST50T3G

SOT-223

5V

1

6

Electrolytic Capacitor

EEEHA1H100P

PANASONIC_D

100uF

6

7

Capacitor

C0805C104K5RAC AUTO

O805

100nF

6

8

Capacitor

CC0805JRNPO9BN330

O805

33pF

2

9

Resistor

CRG0805F4K7

O805

4.7kohm

1

10

Resistor

RT0805FRE0710KL

O805

10kohm

7

11

Power Jack

RASM712X



1

12

USB type B connector

1734346-1



1

13

Pin Header

M20-9990346


3 Pins

5

14

Pin Header

M20-9990246


2 Pins

6

15

Pin Header

M20-9990546


5 Pins

2

16

Pin Header

M20-9970346


2x3 Pins

1