Animatronic Dog Toy

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Animatronic Dog Toy Disection

DogToy.jpg


Product Function and Description

The animated dog toy interacts with children by responding to human touch with motion and sounds. Tripping sensors located on each of the front paws, on the top of the head, and under the chin produces a variety of physical movements such as lifting paws, sitting up, lying down, and bouncing up and down along with various sounds. The purpose of the product is to provide entertainment for children.

Design Considerations

  • The toy must be able to be compact, portable, and lightweight, but still be robust enough to survive being played with by a child.
  • Movements of the toy must be quick even with the cloth covering and stuffing.
  • The mechanism must not fail even if the toy is held in one position when it is activated or its limbs are forced.
  • As it is sold mainly as a stuffed toy, it must be soft and have a natural, aesthetically pleasing appearance for children.

Components and Functions

1. Human Interface

  • Four tactile sensors are located on the head, chin and front paws.
    • Sensors consist of two metal plates separated by a small gap.
    • When vibrated, the plates make contact, complete the circuit, and send a signal to the circuit board.

VibrationSensor.jpg


2. Sensing

  • The sensors described above could be included in this category as they respond not only to human touch, but also to any movement of the surface the toy is resting on.

3. Movements

  • Front legs rotate up and down independently
  • Dog's body can sit up or lie down by raising or lowering both front legs together
  • Dog can bounce up and down by alternately rotating one leg up and the other down

Legrotation.jpg


4. Power Supply - Actuation

  • Three AA batteries provide 4.5 V DC

AAbatteries.jpg

  • Mechanical power comes from two small DC motors, one for the left legs and one for the right.
    • DC motors were used because DC current is available from batteries.
    • DC motors offer quick and easy starting.

DCmotor.jpg


5. Power Conversion

  • Two methods of power conversion are displayed in this system.
    • Belt drive attached directly to the motor shaft
      • Provides increased torque and reduces rotational speed
      • Allows slip to protect the system from damage
    • Gear train
      • Adds additional meachanical advantage

DriveTrain.jpg


6. Motion Conversion

  • The output of the drive system is rotational motion of the toy’s front legs.
  • This is converted to linear motion of the toy up and down by dragging the legs across the ground and forcing the toy’s body upward or lowering it downward.

7. Inteligence

  • The toy’s circuitry provides it with limited intelligence.
    • Each sensor location (head, chin, or paws) triggers a different set of responses.
    • Repeated activation of the same sensor will cause random variations of the response.
      • Example: Triggering the right paw sensor repeatedly will sometimes activate the right leg and sometimes activate the left with no easily recognizable pattern.
    • If the toy’s power is switched off while moving, it will automatically return to the default “sitting” position before it will respond the next time it is powered on.

CircuitBoard.jpg