Self-Driving Cars with Python

TOMASZ KACMAJOR

Trójmiasto

May 25, 2017

Image source: http://www.autonomous-car.com/2015/12/when-will-self-driving-cars-be-ready.html

TOMASZ KACMAJOR

www.tomaszkacmajor.pl

tomasz.kacmajor@gmail.com

AGENDA

LANE LINES FINDING

TRAFFIC SIGN CLASSIFICATION

BEHAVIORAL CLONING

MOTIVATION

THE INDUSTRY

SUMMARY Q&A

LANE LINES FINDING

TRAFFIC SIGN CLASSIFICATION

BEHAVIORAL CLONING

MOTIVATION

MOTIVATION

Self-Driving Car Nanodegree Program

Computer Vision

Deep Learning

Sensor Fusion

Localization

Control

Path Planning

Hiring Partners

Term 1

Term 2

Term 3

MOTIVATION

COMMUNITY

https://pythonprogramming.net/more-interesting-self-driving-python-plays-gta-v/

https://zhengludwig.wordpress.com/projects/self-driving-rc-car/

https://www.youtube.com/watch?v=asQ3vHOwHxw

https://www.youtube.com/watch?v=6oEQXnqpEGc

Self-Driving RC Car

Python plays GTA V

Autonomous RC car

Udacity/Didi SDC Challenge 2017

Arduino/Raspberry Pi projects

Simulators in games

Autonomous RC cars

Public challenges

THE INDUSTRY

HISTORY

A Boy's Life Magazine, 1956

No Hands Across America, 1995

from: https://www.cs.cmu.edu/news/look-ma-no-hands-cmu-vehicle-steered-itself-across-country-20-years-ago

DARPA Grand Challenge, 2005

from: http://www.extremetech.com/extreme/115131-learn-how-to-program-a-self-driving-car-stanfords-ai-guru-says-he-can-teach-you-in-seven-weeks

DARPA Grand Challenge, 2005

http://www.pbs.org/wgbh/nova/tech/cars-drive-themselves.html

DARPA Urban Challenge, 2007

http://www.motortrend.com/news/darpa-urban-challenge-reflections/

DARPA Grand Challenge, 2004

from: http://www.cs.cmu.edu/~curmson/urmsonRobots.html

2009

comma.ai

SELF-DRIVING CARS INDUSTRY

from: http://www.sfchronicle.com/business/article/Partner-up-Self-driving-car-firms-form-tangled-11160522.php

SELF-DRIVING
CARS INDUSTRY

THE INDUSTRY

PURPOSE - SAFETY

Car accidents in Poland

3000 deaths/year  

8 deaths/day 

Growing congestion

Helping elder or disabled people

THE INDUSTRY

COMPLEXITY

Artificial Ingelligence

Programming

Mechanics

Sensors

Localization

Radars

LIDARs

Cameras

Python

C++ 

HD Maps

GPS

Computing

Deep Neural Networks

Computer Vision

Cloud

GPU

Cyber-security

Sociology

Data centers

C

LANE LINES
FINDING

ver. 3.5.2

ver. 3.1.0

LANE LINES FINDING

PIPELINE

Reading image or video frame

Filtering white and yellow colors

Conversion to grayscale

Gaussian blurring

Edge detection

Region of interest definition

Hough lines detection

Filtering Hough lines

Averaging line segments

Applying moving average
​on final lines

   
    import matplotlib.pyplot as plt
    import matplotlib.image as mpimg
    import numpy as np
    import cv2
    import math


    image_name = "test_images/challengeSnap3.jpg"
    image = mpimg.imread(image_name)
    #image = cv2.imread(image_name)
    
    plt.imshow(image)
    plt.show()

LANE LINES FINDING

IMPLEMENTATION

Reading image

  

    image_gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
    image_blurred = cv2.GaussianBlur(image_gray, (5, 5), 0)
    image_edges = cv2.Canny(image_blurred, 40, 80)
    
    plt.imshow(image_edges, cmap='gray')
    plt.show()

LANE LINES FINDING

IMPLEMENTATION

Edge detection - first approach



    h_channel = image[:,:,0]
    l_channel = image[:,:,1]
    s_channel = image[:,:,2]
    
    f, (ax1, ax2, ax3) = plt.subplots(1, 3, figsize=(15, 10))
    ax1.imshow(h_channel, cmap='gray')
    ax1.set_title('R Channel', fontsize=15)
    ax2.imshow(l_channel, cmap='gray')
    ax2.set_title('G Channel', fontsize=15)
    ax3.imshow(s_channel, cmap='gray')
    ax3.set_title('B Channel', fontsize=15)
    plt.show()
    
    image_hls = cv2.cvtColor(image, cv2.COLOR_RGB2HLS)
    h_channel = image_hls[:,:,0]
    l_channel = image_hls[:,:,1]
    s_channel = image_hls[:,:,2]
    
    f, (ax1, ax2, ax3) = plt.subplots(1, 3, figsize=(15, 10))
    ax1.imshow(h_channel, cmap='gray')
    ax1.set_title('H Channel', fontsize=15)
    ax2.imshow(l_channel, cmap='gray')
    ax2.set_title('L Channel', fontsize=15)
    ax3.imshow(s_channel, cmap='gray')
    ax3.set_title('S Channel', fontsize=15)
    plt.show()

LANE LINES FINDING

IMPLEMENTATION

Different color spaces



    lower = np.uint8([  0, 200,   0])
    upper = np.uint8([255, 255, 255])
    white_mask = cv2.inRange(image_hls, lower, upper)
    
    lower = np.uint8([ 10,   0, 100])
    upper = np.uint8([ 40, 255, 255])
    yellow_mask = cv2.inRange(image_hls, lower, upper)
    
    mask = cv2.bitwise_or(white_mask, yellow_mask)
    masked_Image = cv2.bitwise_and(image, image, mask = mask)
    
    plt.imshow(masked_Image, cmap='gray')
    plt.show()

LANE LINES FINDING

IMPLEMENTATION

Filtering white and yellow colors



    image_gray = cv2.cvtColor(masked_Image, cv2.COLOR_BGR2GRAY)
    image_blurred = cv2.GaussianBlur(image_gray, (5, 5), 0)
    image_edges = cv2.Canny(image_blurred, 40, 80)
    
    fig = plt.figure(figsize = (30,20))
    plt.imshow(image_edges, cmap='gray')
    plt.show()

LANE LINES FINDING

IMPLEMENTATION

Edge detection



    imgHeight = image_edges.shape[0]
    imgWidth = image_edges.shape[1]
    yTopMask = imgHeight*0.55
    vertices = np.array([[0, imgHeight], [imgWidth*0.45, yTopMask], [imgWidth*0.55, yTopMask], [imgWidth,imgHeight]], np.int32)
    
    image_w_poly = np.copy(image_edges)
    cv2.polylines(image_w_poly, [vertices], True, color=(255,255,255), thickness=3) 
    plt.imshow(image_w_poly, cmap='gray')
    plt.show()
    
    mask = np.zeros_like(image_edges)  
    cv2.fillPoly(mask, [vertices], 255)
    masked_image = cv2.bitwise_and(image_edges, mask)
    
    fig = plt.figure(figsize = (30,20))
    plt.imshow(masked_image, cmap='gray')
    plt.show()

LANE LINES FINDING

IMPLEMENTATION

Region of interest definition

LANE LINES FINDING

IMPLEMENTATION

Hough lines detection

 

r
\theta

x

y

\theta
\rho
\rho = x cos(\theta) + y sin(\theta)

x

y

LANE LINES FINDING

IMPLEMENTATION

Hough lines detection

 

https://en.wikipedia.org/wiki/Hough_transform

LANE LINES FINDING

IMPLEMENTATION

Hough lines detection

 



    rho = 2
    theta = np.pi/180
    threshold = 15
    min_line_length = 15
    max_line_gap = 5
    
    houghLines = cv2.HoughLinesP(masked_image, rho, theta, threshold, np.array([]), \
                                 minLineLength=min_line_length, maxLineGap=max_line_gap)
    
    houghLinesImage = np.zeros((imgHeight, imgWidth, 3), dtype=np.uint8)    
        
    color=[0, 255, 0]
    thickness=2
    
    for line in houghLines:
        for x1,y1,x2,y2 in line:
            cv2.line(houghLinesImage, (x1, y1), (x2, y2), color, thickness)
            
    α=0.8
    β=1.0
    λ=0.0
    origWithHoughLines = cv2.addWeighted(image, α, houghLinesImage, β, λ)
    fig = plt.figure(figsize = (30,20))
    plt.imshow(origWithHoughLines)
    plt.show()

LANE LINES FINDING

IMPLEMENTATION

Hough lines detection

 



    linesFiltered = []    

    for line in houghLines:
        for x1,y1,x2,y2 in line:
            if not np.isnan(a) or np.isinf(a) or (a == 0):
                if (a > -1.5) and (a < -0.3) :      # 0.3 corresponds to 17 degrees, 
                    linesFiltered.append(line)      # 1.5 corresponds to 56 degrees
                if (a > 0.3) and (a < 1.5) :
                    linesFiltered.append(line)                 
    
    houghLinesFilteredImage = np.zeros((imgHeight, imgWidth, 3), dtype=np.uint8)
    for line in linesFiltered:
            for x1,y1,x2,y2 in line:
                cv2.line(houghLinesFilteredImage, (x1, y1), (x2, y2), \
                    color, thickness)
                
    
    α=0.8
    β=1.0
    λ=0.0
    origWithHoughLinesFiltered = cv2.addWeighted(image, α,\
        houghLinesFilteredImage, β, λ)
    fig = plt.figure(figsize = (30,20))
    plt.imshow(origWithHoughLinesFiltered)
    plt.show()

LANE LINES FINDING

IMPLEMENTATION

Filtering Hough lines

LANE LINES FINDING

IMPLEMENTATION

a_{avg} = \frac{(a_{1}l_{1}^2 + a_{2}l_{2}^2 + ... + a_{n}l_{n}^2)}{l_{1}^2 + l_{2}^2 + ... + l_{n}^2}
a_{1}, l_{1}
a_{2}, l_{2}
a_{4}, l_{4}
a_{5}, l_{5}
a_{3}, l_{3}
a_{5}, l_{5}
a_{avg}

Averaging line segments

LANE LINES FINDING

RESULTS

Sample of another, more complex 
project in the course

My recording - Polish road

My recording - Polish road

TRAFFIC SIGN CLASSIFICATION

TRAFFIC SIGN CLASSIFICATION

Loading the data

Data exploration and visualization

Data preprocessing

Data augmentation

Designing, training and testing a CNN model

Using the model on new images

Analyzing softmax probabilities

IMPLEMENTATION

TRAFFIC SIGN CLASSIFICATION

    import pickle

    training_file = "./traffic-signs-data/train.p"
    validation_file="./traffic-signs-data/valid.p"
    testing_file = "./traffic-signs-data/test.p"
    
    with open(training_file, mode='rb') as f:
        train = pickle.load(f)
    with open(validation_file, mode='rb') as f:
        valid = pickle.load(f)
    with open(testing_file, mode='rb') as f:
        test = pickle.load(f)
        
    X_train, y_train = train['features'], train['labels']
    X_valid, y_valid = valid['features'], valid['labels']
    X_test, y_test = test['features'], test['labels']

    import numpy as np

    n_train = X_train.shape[0]
    n_valid = X_valid.shape[0]
    n_test = X_test.shape[0]
    image_shape = X_train.shape[1:]
    
    n_classes = np.unique(y_train).shape[0]
    
    print("Number of training examples =", n_train)
    print("Number of validation examples =", n_valid)
    print("Number of testing examples =", n_test)
    print("Image data shape =", image_shape)
    print("Number of classes =", n_classes)
Number of training examples = 34799
Number of validation examples = 4410
Number of testing examples = 12630
Image data shape = (32, 32, 3)
Number of classes = 43

Loading data

TRAFFIC SIGN CLASSIFICATION

    import numpy as np
    import matplotlib.pyplot as plt
    import random 
    
    # Visualizations will be shown in the notebook.
    get_ipython().magic('matplotlib inline')
    
    def draw_images_examples(image_array, grid_x, grid_y, title):
        fig = plt.figure(figsize=(grid_x,grid_y))
        fig.suptitle(title, fontsize=20)
     
        for i in range(1,grid_y*grid_x+1):
            index = random.randint(0, len(image_array))
            image = image_array[index].squeeze()
           
            plt.subplot(grid_y,grid_x,i)
            plt.imshow(image)
            
    draw_images_examples(X_train, 16, 4, 'Examples of images from training set')
        
    
    fig = plt.figure(figsize=(12,4))
    n, bins, patches = plt.hist(y_train, n_classes)
    plt.xlabel('Labels')
    plt.ylabel('No. of samples')
    plt.title('Histogram of training samples')
    
    X_train_one_label = X_train[np.where(y_train==0)]
    draw_images_examples(X_train_one_label, 16, 4, 'Examples of images of the same type - Speed limit (20km/h)')

Data exploration

IMPLEMENTATION

TRAFFIC SIGN CLASSIFICATION

IMPLEMENTATION

TRAFFIC SIGN CLASSIFICATION



    def augment_brightness_camera_images(image):
        image1 = cv2.cvtColor(image,cv2.COLOR_RGB2HSV)
        random_bright = .25+np.random.uniform()
        image1[:,:,2] = image1[:,:,2]*random_bright
        image1 = cv2.cvtColor(image1,cv2.COLOR_HSV2RGB)
        return image1
    
    def transform_image(img):    
        ang_range = 25
        ang_rot = np.random.uniform(ang_range)-ang_range/2
        rows,cols,ch = img.shape    
        Rot_M = cv2.getRotationMatrix2D((cols/2,rows/2),ang_rot,1)
            
        img = cv2.warpAffine(img,Rot_M,(cols,rows))    
        img = augment_brightness_camera_images(img)
        
        return img

Data augmentation

IMPLEMENTATION

Train set increased from 34799 to 139148

TRAFFIC SIGN CLASSIFICATION



    def grayscale(img):    
        return cv2.cvtColor(img, cv2.COLOR_RGB2GRAY)[:,:,None]
    
    def normalize(value):
        return value / 255 * 2 - 1
    
    def preprocess_image(image):
        img = grayscale(image)
        img = normalize(img)
        return img

Data preprocessing

IMPLEMENTATION

TRAFFIC SIGN CLASSIFICATION

Convolutional Neural Network

IMPLEMENTATION

from: https://killianlevacher.github.io/blog/posts/post-2016-03-01/img/layeredRepresentation.jpg

https://adeshpande3.github.io/adeshpande3.github.io/A-Beginner%27s-Guide-To-Understanding-Convolutional-Neural-Networks/

TRAFFIC SIGN CLASSIFICATION

Convolutional Neural Network

IMPLEMENTATION

from: https://killianlevacher.github.io/blog/posts/post-2016-03-01/img/layeredRepresentation.jpg

TRAFFIC SIGN CLASSIFICATION

Convolutional Neural Network

IMPLEMENTATION

    import tensorflow as tf
    from tensorflow.contrib.layers import flatten


    # Arguments used for tf.truncated_normal, randomly defines variables for the weights and biases for each layer
    mu = 0
    sigma = 0.1
    
    # Layer 1: Convolutional. Input = 32x32x1. Output = 28x28x6.
    conv1_W = tf.Variable(tf.truncated_normal(shape=(5, 5, 3, 6), mean = mu, stddev = sigma))
    conv1_b = tf.Variable(tf.zeros(6))
    conv1   = tf.nn.conv2d(x, conv1_W, strides=[1, 1, 1, 1], padding='VALID') + conv1_b

    # Activation.
    conv1 = tf.nn.relu(conv1)
    
    # Pooling. Input = 28x28x6. Output = 14x14x6.
    conv1 = tf.nn.avg_pool(conv1, ksize=[1, 2, 2, 1], strides=[1, 2, 2, 1], padding='VALID')

    # Layer 2: Convolutional. Output = 10x10x16.
    conv2_W = tf.Variable(tf.truncated_normal(shape=(5, 5, 6, 16), mean = mu, stddev = sigma))
    conv2_b = tf.Variable(tf.zeros(16))
    conv2   = tf.nn.conv2d(conv1, conv2_W, strides=[1, 1, 1, 1], padding='VALID') + conv2_b
    
    # Activation.
    conv2 = tf.nn.relu(conv2)
        
    # Pooling. Input = 10x10x16. Output = 5x5x16.
    conv2 = tf.nn.avg_pool(conv2, ksize=[1, 2, 2, 1], strides=[1, 2, 2, 1], padding='VALID')

TRAFFIC SIGN CLASSIFICATION

Convolutional Neural Network

IMPLEMENTATION

    
    # Flatten. Input = 5x5x16. Output = 400.
    fc0   = flatten(conv2)
    
    # Layer 3: Fully Connected. Input = 400. Output = 120.
    fc1_W = tf.Variable(tf.truncated_normal(shape=(400, 120), mean = mu, stddev = sigma))
    fc1_b = tf.Variable(tf.zeros(120))
    fc1   = tf.matmul(fc0, fc1_W) + fc1_b
    
    # Activation.
    fc1    = tf.nn.relu(fc1)
    
    # Layer 4: Fully Connected. Input = 120. Output = 84.
    fc2_W  = tf.Variable(tf.truncated_normal(shape=(120, 84), mean = mu, stddev = sigma))
    fc2_b  = tf.Variable(tf.zeros(84))
    fc2    = tf.matmul(fc1, fc2_W) + fc2_b
    
    # Activation.
    fc2    = tf.nn.relu(fc2)
    
    # Layer 5: Fully Connected. Input = 84. Output = 43.
    fc3_W  = tf.Variable(tf.truncated_normal(shape=(84, n_classes), mean = mu, stddev = sigma))
    fc3_b  = tf.Variable(tf.zeros(n_classes))
    logits = tf.matmul(fc2, fc3_W) + fc3_b
    
    return logits

TRAFFIC SIGN CLASSIFICATION

CNN Training

IMPLEMENTATION

    from sklearn.utils import shuffle
    
    EPOCHS = 100
    BATCH_SIZE = 128

    with tf.Session() as sess:
        sess.run(tf.global_variables_initializer())
        num_examples = len(X_train_processed)
        
        print("Training...")
        print()
        for i in range(EPOCHS):
            X_train_processed, y_train = shuffle(X_train_processed, y_train)
            for offset in range(0, num_examples, BATCH_SIZE):
                end = offset + BATCH_SIZE
                batch_x, batch_y = X_train_processed[offset:end], y_train[offset:end]
                train_op, cost = sess.run([training_operation, loss_operation], feed_dict={x: batch_x, y: batch_y})
                
            validation_accuracy = evaluate(X_valid_processed, y_valid)
            print("EPOCH; {}; Valid.Acc.; {:.3f}; Loss; {:.5f}".format(i+1, validation_accuracy, cost))
            cost_arr.append(cost)
          
            
        saver.save(sess, './lenet')
        print("Model saved")

Feeding the model with batches of samples

TRAFFIC SIGN CLASSIFICATION

RESULTS

  • Initial LeNet model - 91 %
  • Input images normalization - ~91 %
  • Training set augmantation - 93 %
  • Learn rate optimization - 95 %
  • Finding optimum image transformations during training set augmentation - 96 %
  • Trying different pool methods, dropout, choosing L2 loss, tuning learn rate again - 96.8

Methodology

Final results

  • Training set accuracy of 99.5 %
  • Validation set accuracy of 96.8 %
  • Test set accuracy of 94.6 %

TRAFFIC SIGN CLASSIFICATION

RESULTS

Speed limit (30km/h)

Bumpy road

General caution

Keep right

No entry

Slippery road

Predictions:

Probability:

94%

99%

100%

100%

100%

99%

3% for - Speed limit (30km/h)

TRAFFIC SIGN CLASSIFICATION

RESULTS

Test samples from Polish roads

TRAFFIC SIGN CLASSIFICATION

RESULTS

No passing for vehicles
over 3.5 metric tons

Yield

Ahead only

Speed limit (50km/h)

No passing for vehicles
over 3.5 metric tons

Ahead only

Keep right

100%

100%

99%

100%

92%

89%

45%

6.4% for - Speed limit (80km/h)

8.3% for - End of no passing
by vehicles over 3.5 metric tons

39% for - Turn right ahead
12% for - No vehicles
1.3% for - End of all speed and passing limits
 

Test samples from Polish roads

BEHAVIORAL
CLONING

BEHAVIORAL
CLONING

Collect data of driving behavior

Build CNN which predicts
    steering angles

Train and validate the model

Test the model

DATA COLLECTION

BEHAVIORAL CLONING

DATA COLLECTION

BEHAVIORAL CLONING

DATA COLLECTION

BEHAVIORAL CLONING

Left camera

Center camera

Right camera

DATA AUGMENTATION

BEHAVIORAL CLONING

Original image

Flipped image

DATA AUGMENTATION

BEHAVIORAL CLONING

CONVOLUTIONAL NEURAL NETWORK

BEHAVIORAL CLONING

from: https://devblogs.nvidia.com/parallelforall/deep-learning-self-driving-cars/

27 million connections
250 thousand parameters

def build_nvidia_model(dropout=.4):
    model = Sequential()
    input_shape_before_crop=(IMAGE_ROWS_BEFORE_CROP,IMAGE_COLS, CHANNELS)
    input_shape_after_crop=(IMAGE_ROWS, IMAGE_COLS, CHANNELS)
    # trim image to only see section with the road
    model.add(Cropping2D(cropping=((IMAGE_CROP_TOP,IMAGE_CROP_BOTTOM), (0,0)),\
        input_shape=input_shape_before_crop))
    # pixels normalization using Lambda method
    model.add(Lambda(lambda x: x/127.5-1, input_shape=input_shape_after_crop))
    
    model.add(Conv2D(24, (5, 5), activation='elu', strides=(2, 2)))
    model.add(Dropout(dropout))
    model.add(Conv2D(36, (5, 5), activation='elu', strides=(2, 2)))
    model.add(Dropout(dropout))
    model.add(Conv2D(48, (5, 5), activation='elu', strides=(2, 2)))
    model.add(Dropout(dropout))
    model.add(Conv2D(64, (3, 3), activation='elu'))
    model.add(Dropout(dropout))
    model.add(Conv2D(64, (3, 3), activation='elu'))
    model.add(Dropout(dropout))
    model.add(Flatten())    
    model.add(Dense(100, activation='elu'))
    model.add(Dense(50, activation='elu'))
    model.add(Dense(10, activation='elu'))
    model.add(Dense(1))
    
    optimizer = Adam(lr=0.001)
    model.compile(optimizer=optimizer,
                  loss='mse')
    return model
from keras.models import Sequential
from keras.layers import Dense, Dropout, Flatten, Lambda
from keras.layers import Conv2D, Cropping2D
from keras.optimizers import Adam

Architecture from Nvidia

paper

IMPLEMENTATION

BEHAVIORAL CLONING


    BATCH_SIZE = 128
    NO_EPOCHS = 3
    
    train_generator = generator(train_samples, BATCH_SIZE, ANGLE_CORRECTION)
    validation_generator = generator(validation_samples, BATCH_SIZE, ANGLE_CORRECTION)
    
    model = build_nvidia_model()
    
    model.fit_generator(train_generator, steps_per_epoch=len(train_samples)/BATCH_SIZE, \
                        epochs=NO_EPOCHS, validation_data=validation_generator, \
                        validation_steps=len(validation_samples)/BATCH_SIZE)
    
    model.save('model.h5')

Model building

CONVOLUTIONAL NEURAL NETWORK

BEHAVIORAL CLONING


    def generator(samples, batch_size, angle_correction):
        num_samples = len(samples)
        angle_corrections = [0, angle_correction, -angle_correction]
        
        while 1: # Loop forever so the generator never terminates
            shuffle(samples)
            for offset in range(0, num_samples, batch_size):
                batch_samples = samples[offset:offset+batch_size]
                
                images = []
                angles = []
                for batch_sample in batch_samples:
                    camera_index = get_camera_index()
                    image = get_image_from_sample_line(batch_sample, camera_index, resizing=True)                
                    steering = float(batch_sample[3]) + angle_corrections[camera_index]
                    
                    image, steering = flip_image_and_steering(image, steering)
                    
                    images.append(image)
                    angles.append(steering)
                
                X_train = np.array(images)
                y_train = np.array(angles)
                yield sklearn.utils.shuffle(X_train, y_train)

Generators

RESULTS

BEHAVIORAL CLONING

SUMMARY

Thank 

You!

www.tomaszkacmajor.pl

tomasz.kacmajor@gmail.com
 

Trójmiasto

All code for the presented projects available on https://github.com/tomaszkacmajor

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