ai_robot.py

#!/usr/bin/python3

#Originally be Alasdair Allen (see below), modified by Ben Everard 2023

# Copyright (c) 2022 Raspberry Pi Ltd
# Author: Alasdair Allan <alasdair@raspberrypi.com>
# SPDX-License-Identifier: BSD-3-Clause

# A TensorFlow Lite example for Picamera2 on Raspberry Pi OS Bullseye
#
# Install necessary dependences before starting,
#
# $ sudo apt update
# $ sudo apt install build-essential
# $ sudo apt install libatlas-base-dev
# $ sudo apt install python3-pip
# $ pip3 install tflite-runtime
# $ pip3 install opencv-python==4.4.0.46
# $ pip3 install pillow
# $ pip3 install numpy
#
# and run from the command line,
#
# $ python3 real_time_with_labels.py --model mobilenet_v2.tflite --label coco_labels.txt

import argparse

import numpy as np
import tflite_runtime.interpreter as tflite

from picamera2 import MappedArray, Picamera2, Preview

from adafruit_motorkit import MotorKit
import time


seeking = "person"

normalSize = (640, 480)
lowresSize = (320, 240)

rectangles = []


def ReadLabelFile(file_path):
    with open(file_path, 'r') as f:
        lines = f.readlines()
    ret = {}
    for line in lines:
        pair = line.strip().split(maxsplit=1)
        ret[int(pair[0])] = pair[1].strip()
    return ret


def InferenceTensorFlow(image, model, output, camera, label=None):
    global rectangles

    if label:
        labels = ReadLabelFile(label)
    else:
        labels = None

    interpreter = tflite.Interpreter(model_path=model, num_threads=4)
    interpreter.allocate_tensors()

    input_details = interpreter.get_input_details()
    output_details = interpreter.get_output_details()
    height = input_details[0]['shape'][1]
    width = input_details[0]['shape'][2]
    floating_model = False
    if input_details[0]['dtype'] == np.float32:
        floating_model = True

    rgb = cv2.cvtColor(image, cv2.COLOR_GRAY2RGB)
    initial_h, initial_w, channels = rgb.shape

    picture = cv2.resize(rgb, (width, height))

    input_data = np.expand_dims(picture, axis=0)
    if floating_model:
        input_data = (np.float32(input_data) - 127.5) / 127.5

    interpreter.set_tensor(input_details[0]['index'], input_data)

    interpreter.invoke()

    detected_boxes = interpreter.get_tensor(output_details[0]['index'])
    detected_classes = interpreter.get_tensor(output_details[1]['index'])
    detected_scores = interpreter.get_tensor(output_details[2]['index'])
    num_boxes = interpreter.get_tensor(output_details[3]['index'])

    for i in range(int(num_boxes)):
        top, left, bottom, right = detected_boxes[0][i]
        classId = int(detected_classes[0][i])
        score = detected_scores[0][i]
        if score > 0.5:
            if (labels[classId] == seeking):
                print("found on camera ", camera)
                return True
    return False

#initialise motors:

kit = MotorKit()

max_speed = 0.3
motors_forward = [1, 1, -1, -1]
motors = [kit.motor1, kit.motor2, kit.motor3, kit.motor4]


#process arguments
parser = argparse.ArgumentParser()
parser.add_argument('--model', help='Path of the detection model.', required=True)
parser.add_argument('--label', help='Path of the labels file.')
parser.add_argument('--output', help='File path of the output image.')
args = parser.parse_args()

if (args.output):
	output_file = args.output
else:
	output_file = 'out.jpg'

if (args.label):
	label_file = args.label
else:
	label_file = None


#initialise cameras
picam0 = Picamera2(0)
picam0.start_preview(Preview.QTGL)
config = picam0.create_preview_configuration(main={"size": normalSize},
                                         lores={"size": lowresSize, "format": "YUV420"})
picam0.configure(config)
stride = picam0.stream_configuration("lores")["stride"]
picam0.start()

picam1 = Picamera2(1)
picam1.start_preview(Preview.QTGL)
config = picam1.create_preview_configuration(main={"size": normalSize},
                                         lores={"size": lowresSize, "format": "YUV420"})
picam1.configure(config)
stride = picam1.stream_configuration("lores")["stride"]
picam1.start()

#import here because of a clash with picamera
import cv2

max_speed = 0.5
left_direction = 1
right_direction = -1

def set_motors(left, right):
	left_speed = 0
	right_speed = 0
	if left:
		left_speed = max_speed * left_direction
	if right:
		right_speed = max_speed * right_direction
		
	kit.motor1.throttle = left_speed
	kit.motor2.throttle = left_speed
	kit.motor3.throttle = right_speed
	kit.motor4.throttle = right_speed

while True:

	buffer = picam0.capture_buffer("lores")
	grey = buffer[:stride * lowresSize[1]].reshape((lowresSize[1], stride))
	found_left = InferenceTensorFlow(grey, args.model, output_file,0, label_file)

	buffer = picam1.capture_buffer("lores")
	grey = buffer[:stride * lowresSize[1]].reshape((lowresSize[1], stride))
	found_right = InferenceTensorFlow(grey, args.model, output_file,1, label_file)
	
	set_motors(found_left, found_right)