System Introspection for System Analysis on Mobile Devices

The selected sensors give a good impression the data collected on differenttasks the robot can per<strong>for</strong>m. Laser and SLAM sensors are used <strong>for</strong> navigation,person and speech sensor represent in<strong>for</strong>mation needed <strong>for</strong> human-machineinteraction.The USB camera was used <strong>for</strong> testing the capability of sendingbigger payloads by using higher frequencies. Laser and SLAM sensors providetheir data as arrays of numbers and some additionally in<strong>for</strong>mation about therobot position. To filter this data the different arrays have been translated toa visual presentation as image. The additional data, like the position of therobot, is added to each images. XMPP does not support binary attachment.In order to still send the image, each image is decoded to a string by usingbase64 2 and then attached to a new message. On the client side the stringis encoded with base64 back to an image. Base64 allows to translate a bytearray to a string and vice versa. The same principle has been used <strong>for</strong> sendingimages captured by the USB camera. The data of the person sensor and thespeech sensor is provided as string containing in<strong>for</strong>mation about spoken wordsor angle of leg pairs from persons standing in front of the robot. This data isadded as normal String-pair to a message.Each implemented component thread controlling an actuator can receive specificcommands which are <strong>for</strong>warded to the robot via the component holder.The component thread <strong>for</strong> the navigation actuator can receive X/Y coordinates<strong>for</strong> navigation or direct commands like “manual_stop“. The componentthread communicating with the speech actuator parses the sentence to be spokenand calls the corresponding function on the speech actuator by using thecomponent holder.6.4 ClientThe design <strong>for</strong> the client described in chapter 5.3 has been implemented on thethe android operation system and on a common computer. To display the dataof the component threads a tabbed navigation system is implemented in bothclients presenting data inside tab views. Although the views presented can besimilar implemented, the system in the background <strong>for</strong> controlling the viewsis different <strong>for</strong> the clients. On mobile devices the resources are very limitedcompared to the common computer. At the time of this thesis a mobile deviceis not capable of using multi-cores <strong>for</strong> threading. On the common computermore resources are available which allows to use more resources and displaymore views at once. For example two views presenting the laser data and thenavigation planing can be combined inside one view. The following sectiongives an introduction of the implementation on both systems.2 http://www.webcitation.org/5x3gUQW3U - Base64 (RFC 4648)42