ECRobotNXT向导（7）（中英文对照）

旭日东升

NXTracer

NXT巡线车

NXTracer is a line tracing tricycle robot and has one Light Sensor, two Touch Sensors, one Ultrasonic Sensor and two Servo Motors. The Touch Sensors and the Ultrasonic Sensor are not used in the shipped controller model. This robot detects a black line by the Light Sensor and follows the black line on the track. NXTracer demo files are stored in nxtracer directory.

NXTracer是由一个光传感器，两个触摸传感器，一个超声波传感器和两个伺服电机组成的单巡线的三轮车机器人。在出货的控制器模型不使用触摸传感器和超声波传感器。这个机器人通过光传感器检测一条黑线，巡赛道上的黑线前进。NXTracer演示文件保存在nxtracer目录下。

nxtracer.mdl is the main model file that includes a robot plant model and virtual track model. The Control strategy is modeled in nxtracer_ctrl.mdl file that is referenced via a Model block in nxtracer.mdl.

nxtracer.mdl是模型的主模块文件，该文件包括机器人被控对象模型和虚拟轨迹模型。控制策略在nxtracer_ctrl.mdl文件中建立模型，通过Model模块在nxtracer.mdl中参考使用。


When the simulation starts, the Virtual Reality Viewer window and XY Map Graph figure come up to monitor the behavior of the robot on virtual track.

当模拟开始时，虚拟现实浏览器窗口和XY视图窗口将监视虚拟轨道上的机器人的行为。

The NXTracer has the following specifications. A real NXTracer can be built using a LEGO Mindstorms NXT Educational Kit, but detailed parts construction is different from the model used in the Virtual Reality Viewer.

NXTracer具有下列细节。一个真正NXTracer可能使用LEGO MINDSTORMS NXT教育套件，但具体的搭建组件同虚拟现实浏览器所使用的模型有所不同。

Model-Based Design Experience with NXTracer:

NXTracer基于模型的设计经验：

Objective: Developm a faster line tracing robot that has self- learning

The shipped NXTracer already has a dynamic threshold level configuration feature to recognize the drawn line in robust way. However, the line tracing algorithm is simple and not very effective. So this objective allows readers to improve the robot to make it trace the line faster. There are several hints that may help readers develop a faster line tracing robot.

Hint-1: The robot may memorize the line layout during the first round

As described in the Model-Based Design Experience with NXTmouse, the robot can recognize the position and the rotation angle. So an application can be developed that allows the robot to memorize the line layout during the first round as a kind of self-learning feature.

Hint-2: The robot may trace the line faster and faster after each round

After the first round, the robot may be able to trace the line more effectively based on the self-learned line layout obtained during the first round. The self-learning algorithm may be continuously improved through the subsequent rounds on the line track.

目的：设计具有自学习能力更快的巡线机器人

发布NXTracer动态阈值级别的配置功能，在稳定可靠的方式识别巡线。该巡线跟踪算法简单，但是不是很有效。因此该目标要求读者提高机器人更快地巡线能力。以下几个提示可以帮助读者设计更快的巡线机器人。

提示1：机器人可以记忆第一轮巡线的位置

同NXTmouse的基于模型设计经验介绍，机器人可以识别的位置和旋转角度。因此开发应用将第一轮作为一种自我学习特性，使机器人的记忆巡线布局。

提示2：机器人可以每圈后可以巡线越来越快

第一圈之后，机器人可以基于第一圈的自学习巡线布局可以更有效完成巡线设计。通过随后的几轮巡线轨迹自学习算法可以不断的改进。