想象#

VEX EXP 的视觉传感器可以检测并追踪颜色特征和颜色代码。这使得视觉传感器能够分析周围环境并根据检测到的视觉数据做出反应。以下是所有方法的列表：

方法——从视觉传感器获取数据。

  • take_snapshot – 捕获特定颜色特征或颜色代码的数据。

  • largest_object – 立即从快照中选择最大的对象。

  • 已安装 – 视觉传感器是否连接到 EXP Brain。

属性 – 从 take_snapshot 返回的对象数据。

  • .exists – 以布尔值表示该对象是否存在于当前检测中。

  • .width – 检测到的物体的宽度（以像素为单位）。

  • .height – 检测到的物体的高度（以像素为单位）。

  • .centerX – 对象中心的 X 位置（以像素为单位）。

  • .centerY – 对象中心的 Y 位置（以像素为单位）。

  • .angle – 颜色代码的方向（以度为单位）。

  • .originX – 对象左上角的 X 位置（以像素为单位）。

  • .originY – 对象左上角的 Y 位置（以像素为单位）。

构造函数——手动初始化和配置视觉传感器。

In VEXcode, the initialization of the Vision Sensor and its configured Color Signatures and Color Codes is done automatically. For the examples below, the configured Vision Sensor will be named vision_1. To manually initialize and construct a Vision Sensor and its Color Signatures and Color Codes, refer to the Constructors section on this page.

方法#

take_snapshot#

take_snapshot filters the data from the Vision Sensor frame to return a tuple. The Vision Sensor can detect configured Color Signatures and Color Codes.

必须先在 Vision Utility 中配置 颜色签名 和 颜色代码，然后才能使用此方法。

该元组存储的对象按宽度从大到小排序，从索引 0 开始。每个对象的 属性 可以通过其索引访问。如果未检测到匹配的对象，则返回一个空元组。

Usage:
vision_1.take_snapshot(SIGNATURE)

参数

描述

SIGNATURE

What signature to get data of. This is the name of the Vision Sensor, two underscores, and then the Color Signature’s or Color Code’s name. For example: vision_1__RED_BOX.

 
# Move forward if a red object is detected
while True:
    red_box = vision_1.take_snapshot(vision_1__RED_BOX)
    if red_box:
        drivetrain.drive_for(FORWARD, 10, MM)
    wait(5, MSEC)

色彩签名#

颜色特征是视觉传感器能够识别的独特颜色。这些特征使传感器能够根据物体的颜色检测和跟踪物体。配置颜色特征后，传感器可以识别其视野范围内具有该特定颜色的物体。颜色特征与 take_snapshot 一起使用，可以实时处理和检测彩色物体。

In order to use a configured Color Signature in a project, its name must be the name of the Vision Sensor, two underscores, and then the Color Signature’s name. For example: vision_1__RED_BOX.

# Display if any objects match the RED_BOX signature
while True:
    brain.screen.set_cursor(1, 1)
    brain.screen.clear_screen()
    # Change to any configured Color Signature
    red_box = vision_1.take_snapshot(vision_1__RED_BOX)
    if red_box:
        brain.screen.print("Color signature")
        brain.screen.next_row()
        brain.screen.print("detected!")
        wait(100, MSEC)

颜色代码#

颜色代码是由按特定顺序排列的颜色特征组成的结构化模式。这些代码使视觉传感器能够识别预定义的颜色模式。颜色代码可用于识别复杂物体或为自主导航创建独特的标记。

In order to use a configured Color Code in a project, its name must be the name of the Vision Sensor, two underscores, and then the Color Code’s name. For example: vision_1__BOX_CODE.

# Display if any objects match the BOX_CODE code
while True:
    brain.screen.set_cursor(1, 1)
    brain.screen.clear_screen()
    # Change to any configured Color Code
    box_code = vision_1.take_snapshot(vision_1__BOX_CODE)
    if box_code:
        brain.screen.print("Color code")
        brain.screen.next_row()
        brain.screen.print("detected!")
        wait(100, MSEC)

largest_object#

largest_object retrieves the largest detected object to get data from in the tuple returned from the latest use of take_snapshot.

此方法可用于始终从元组中获取最大对象，而无需指定索引。

Usage:
vision_1.largest_object

# Turn slowly until the largest object is centered in
# front of the Vision Sensor
drivetrain.set_turn_velocity(10, PERCENT)
drivetrain.turn(RIGHT)

while True:
    red_box = vision_1.take_snapshot(vision_1__RED_BOX)

    if red_box:
        if 140 < vision_1.largest_object().centerX < 180: 
            drivetrain.stop()

    wait(10,MSEC)

installed#

installed returns a Boolean indicating whether the Vision Sensor is currently connected to the EXP Brain.

  • True – The Vision Sensor is connected to the EXP Brain.

  • False – The Vision Sensor is not connected to the EXP Brain.

参数

描述

该方法没有参数。

 
# Display a message if the Vision Sensor is connected
if vision_1.installed():
    brain.screen.print("Vision Sensor")
    brain.screen.next_row()
    brain.screen.print("Installed!")

特性#

使用 take_snapshot 后，元组中存储的每个对象包含 8 个属性。

Some property values are based off of the detected object’s position in the Vision Sensor’s view at the time that take_snapshot was used. The Vision Sensor has a resolution of 316 by 212 pixels.

.exists#

.exists returns a Boolean indicating if the index exists in the tuple or not.

  • True: The index exists.

  • False: The index does not exist.

# Check if at least at least one red objects is detected
# You will receive an error if no objects are detected

while True:
    brain.screen.clear_screen()
    brain.screen.set_cursor(1, 1)
    red_objects = vision_1.take_snapshot(vision_1__RED_BOX)

    if red_objects:
        if red_objects[0].exists:
            brain.screen.print("At least 1")
            
    else:
        brain.screen.print("No red objects")

    wait(0.5, SECONDS)

.width#

.width returns the width of the detected object in pixels, which is an integer between 1 and 316.

# Move towards a blue object until its width is
# larger than 100 pixels
while True:
    blue_box = vision_1.take_snapshot(vision_1__BLUE_BOX)

    if blue_box:
        if blue_box[0].width < 100:
            drivetrain.drive_for(FORWARD, 10, MM)
    else:
        drivetrain.stop()

    wait(50, MSEC)

.height#

.height returns the height of the detected object in pixels, which is an integer between 1 and 212.

# Move towards a blue object until its height is
# larger than 100 pixels
while True:
    blue_box = vision_1.take_snapshot(vision_1__BLUE_BOX)

    if blue_box:
        if blue_box[0].height < 100:
            drivetrain.drive_for(FORWARD, 10, MM)
    else:
        drivetrain.stop()

    wait(50, MSEC)

.centerX#

.centerX returns the x-coordinate of the detected object’s center in pixels, which is an integer between 0 and 316.

# Turn slowly until the largest blue object is centered
# in front of the Vision Sensor.
drivetrain.set_turn_velocity(10, PERCENT)
drivetrain.turn(RIGHT)

while True:
    blue_box = vision_1.take_snapshot(vision_1__BLUE_BOX)

    if blue_box:
        if 140 < vision_1.largest_object().centerX < 180: 
            drivetrain.stop()

    wait(10,MSEC)

.centerY#

.centerY returns the y-coordinate of the detected object’s center in pixels, which is an integer between 0 and 212.

# Move towards a blue object until its
# center y-coordinate is more than 140 pixels
while True:
    blue_box = vision_1.take_snapshot(vision_1__BLUE_BOX)

    if blue_box:
        if blue_box[0].centerY < 140:
            drivetrain.drive(FORWARD)
    else:
        drivetrain.stop()

    wait(50, MSEC)

.angle#

.angle returns the orientation of the detected object in degrees, which is an integer between 0 and 316.

# Turn left or right depending on how a
# configured box code is rotated
while True: 
    box_code = vision_1.take_snapshot(vision_1__BOX_CODE)

    if box_code: 
        if 70 < box_code[0].angle < 110:
            drivetrain.turn_for(RIGHT, 45, DEGREES)
            
        elif 250 < box_code[0].angle < 290:
            drivetrain.turn_for(LEFT, 45, DEGREES)
        
        else:
            drivetrain.stop()

    wait(50, MSEC)

.originX#

.originX returns the x-coordinate of the top-left corner of the detected object’s bounding box in pixels, which is an integer between 0 and 316.

# Display if a red object is to the
# left or the right
while True:
    brain.screen.clear_screen()
    brain.screen.set_cursor(1,1)
    
    red_box = vision_1.take_snapshot(vision_1__RED_BOX)
    
    if red_box:
        if red_box[0].originX < 160:
            brain.screen.print("To the left!")
        else: 
            brain.screen.print("To the right!")

    wait(50, MSEC)

.originY#

.originY returns the y-coordinate of the top-left corner of the detected object’s bounding box in pixels, which is an integer between 0 and 212.

# Display if a red object is close or far
# from the robot
while True:
    brain.screen.clear_screen()
    brain.screen.set_cursor(1,1)
    
    red_box = vision_1.take_snapshot(vision_1__RED_BOX)

    if red_box:
        if red_box[0].originY < 80:
            brain.screen.print("Far")
        else: 
            brain.screen.print("Close")

    wait(50, MSEC)

构造函数#

Constructors are used to manually create Vision, Signature, and Code objects, which are necessary for configuring the Vision Sensor outside of VEXcode.

For the examples below, the configured Vision Sensor will be named vision_1, and the configured Color Signature objects, such as RED_BOX, will be used in all subsequent examples throughout this API documentation when referring to Vision class methods.

Vision Sensor#

Vision creates a Vision Sensor.

用法

Vision(port, brightness, sigs)

参数

描述

port

视觉传感器连接到的有效 智能端口。

brightness

**可选。**视觉传感器的亮度值，从 1 到 100。

sigs

**可选。**一个或多个 颜色签名 或 颜色代码 对象的名称。

 
# Create a new Signature "RED_BOX" with the Colordesc class
RED_BOX = Signature(1, -3911, -3435, -3673,10879, 11421, 11150,2.5, 0)
# Create a new Vision Sensor "vision_1" with the Vision
# class, with the "RED_BOX" Signature.
vision_1 = Vision(Ports.PORT1, 100, RED_BOX)

# Move forward if a red object is detected
while True:
    red_object = vision_1.take_snapshot(RED_BOX)
    if red_object:
        drivetrain.drive_for(FORWARD, 10, MM)
    wait(5, MSEC)

Color Signature#

Signature creates a Color Signature. Up to seven different Color Signatures can be stored on a Vision Sensor at once.

用法：

Signature(index, uMin, uMax, uMean, vMin, vMax, vMean, rgb, type)

范围

描述

index

The Signature object’s index, from 1 - 7. Note: Creating two Signature objects with the same index number will cause the second created object to override the first.

uMin

The value from uMin in the Vision Utility.

uMax

The value from uMax in the Vision Utility.

uMean

The value from uMean in the Vision Utility.

vMin

The value from vMin in the Vision Utility.

vMax

The value from vMax in the Vision Utility.

vMean

The value from vMean in the Vision Utility.

rgb

The value from rgb in the Vision Utility.

type

The value from type in the Vision Utility.

要获取创建颜色签名的值，请转到 Vision Utility。配置颜色签名后，从配置窗口复制参数值。

# Create a new Signature RED_BOX with the Colordesc class
RED_BOX = Signature(1, 10121, 10757, 10439,-1657, -1223, -1440,2.5, 1)
# Create a new Vision Sensor "vision_1" with the Vision
# class, with the RED_BOX Signature.
vision_1 = Vision(Ports.PORT1, 100, RED_BOX)

# Move forward if a red object is detected
while True:
    red_object = vision_1.take_snapshot(RED_BOX)
    if red_object:
        drivetrain.drive_for(FORWARD, 10, MM)
    wait(5, MSEC)

Color Code#

Code creates a Color Code. It requires at least two already defined Color Signatures in order to be used. Up to eight different Color Codes can be stored on a Vision Sensor at once.

用法：

Code(sig1, sig2, sig3, sig4, sig5)

范围

描述

sig1

先前创建的 颜色签名。

sig2

先前创建的 颜色签名。

sig3

可选。 之前创建的 颜色签名。

sig4

可选。 之前创建的 颜色签名。

sig5

可选。 之前创建的 颜色签名。

 
# Create two new Signatures for a red and blue box
RED_BOX = Signature(1, 10121, 10757, 10439,-1657, -1223, -1440, 2.5, 1)
BLUE_BOX = Signature(2, -4443, -3373, -3908,6253, 7741, 6997, 2.5, 1)
# Create a Color Code for a red box to the left of a blue box
RED_BLUE = Code(RED_BOX, BLUE_BOX)
# Create a new Vision Sensor "vision_1" with the Vision
# class, with the red_box and blue_box Signatures.
vision_1 = Vision(Ports.PORT1, 100, RED_BOX, BLUE_BOX)

# Display a message if Color Code is detected
while True:
    brain.screen.set_cursor(1, 1)
    brain.screen.clear_screen()
    # Change to any configured Color Code
    box_code = vision_1.take_snapshot(RED_BLUE)
    if box_code:
        brain.screen.print("Color code")
        brain.screen.next_row()
        brain.screen.print("detected!")
        wait(100, MSEC)
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