qhoenix

Flappy Bird with Q-Learning implementation on Xilinx Digilent Basys 3 Artix-7 FPGA Board.

Introduction

Flappy Bird is a 2D mobile game. A bird named “Faby” continuously move to the left. The bird briefly flaps (jump) upward each time we pressed the space key. A set of pipes keep moving right. The bird died once it touch the pipes, ground or sky. We implement the game on the FPGA board. Using keyboard as input and VGA as output. Also, we use Q-Learning method to train the bird flaps by it self on the same FPGA board. Once it’s fully trained, it should be able to set the high score.

Getting Started

Prerequisites

• Xilinx Digilent Basys 3 Artix-7 FPGA Board.
• Vivado Design Suite - HLx Editions
• A monitor and a VGA cable.
• A keyboard.

Buliding Project

• From source

  • Main code: src/scouce/core/
  • Ip(block memory and keyboard control): src/source/
  • Constrain file: src/source/constrain
  • Original images: src/img/img/
  • coe files converted from original images: src/img/coe

• Open porject directly

  • flappyQ2/flappyQ2.xpr

Usage

• VGA: Connect to monitor as output.
• USB: Connect to keyboard. Space key is the input.
• SW0: Switch mode between keyboard control and Q-Learning mode.
• Keyboard mode: Switch SW0 to 0 (down position). Use space key on the keyboard to control the bird.
• Q-Learning mode: Switch SW0 to 1 (up position). Only switch to Q-Learning mode when the game is at HOLD state. That is, the bird stay at original position and no pipes appear on the screen.

System specification

top module

Object Position

• Basic size info (in pixels)
  • Screen: 512 * 288
  • pipe width: 52
  • bird: 23 * 34
• get_bird_pos
• get_pipes_pos
• get_background_offset

Display

• pixel_gen
• vga_controller

Q-Learning

• qlearning
• getQLState

Other Module

• collision_detection
• KeyboardDecoder
• Clock_Divider

Q-Learning

• Qtable

𝑆𝑥 = 𝑥/𝑅𝑒𝑠𝑜𝑙𝑢𝑡𝑖𝑜𝑛, 𝑆𝑦 = 𝑦/𝑅𝑒𝑠𝑜𝑙𝑢𝑡𝑖𝑜𝑛, 𝑅𝑒𝑠𝑜𝑙𝑢𝑡𝑖𝑜𝑛 = 20

State (Sx, Sy)	Jump	Don't jump
0, 0	4986	0
0, 1	4975	0
:	:	:
6, 13	3508	0
6, 14	-2498	3376
:	:	:
13, 25	0	0

• Algorithm

Initialize Qtable
repeat
    if (is_collide)
        Q[pSx][pSy][pA] = (1-alpha)*Q[pSx][pSy][pA] + alpha*(reward_dead + gamma * max(Q[Sx][Sy]))
    else
        Q[pSx][pSy][pA] = (1-alpha)*Q[pSx][pSy][pA] + alpha*(reward_alive + gamma * max(Q[Sx][Sy]))
        if (Q[Sx][Sy][0] >= Q[Sx][Sy][1])
            don't jump
        else
            jump

Experimental results

Episode	score
24	2
27	9
28	16
29	17
33	34
34	98
36	99+

Reference

SarvagyaVaish's project enhuiz's project