**7. Conclusion**

**Figure 10** shows the dialog generated by the wearable display. Each robot is equipped with a unique augmented reality marker for facilitating the process of overlaying the computergenerated information over the real scene. The operator, with the multimodal hand controller, will have the capability of visually selecting the options suggested by the robot to complete

While the GUI on the wearable display enables the operator to intuitively control and monitor the robot, other humans who share the same working environment (Passerby) might encounter difficulties in accommodating this robot's motion and inadvertently cross into its intended path. The laser writer is provided to overcome this problem by providing passersby with visual indications of the robot's intentions. **Figure 11** shows one possible implementation for this system. In this scenario, this laser system allows the robot to project the direction of its trajectory, before moving from one point to another. Particularly, the robot is able to indicate: 'stop', 'forward', 'backward', 'turn left' and 'turn right' as text or line-graphic symbols.

The proposed framework for the dual-modality AR system was implemented for deployment in a laboratory setting where humans and mobile robots are expected to coexist and operate in close proximity. The mobile platform was 'let loose' within the laboratory without any prior briefing to the other laboratory users. Third party human-robot interaction was observed, and a 'qualitative' feedback was solicited from the 'unsuspecting' human. Two scenarios were

the task. This offers a more intuitive and convenient way to interact with the robot.

**Figure 10.** Dialog menu for Group 1 interactants.

176 Recent Advances in Robotic Systems

**Figure 11.** Laser notification to all interactants and LCD menus.

**6. Discussion**

In this chapter, we highlight the application of laser-generated outline-graphics as a viable addition to 'augmented-reality'. Its images are bright and of high contrast. This lends itself to applications in natural environments, both indoors and outdoors, where the ambient lighting is expected to be relatively bright. Whilst unfilled graphics may be considered as a deficiency, when attempting to generate visually appealing GUI menu with filled graphical images, it can be used effectively to project images and outline text onto the surrounding surfaces. These images can be viewed without the aid of any wearable devices in a natural environment.

In addition, we proposed a design framework for GUI implementation in human-robot shared environments. In this framework, we identify specific requirements of the first party, human in direct control of the robot and the requirements of the third party, humans in the operating vicinity of the robot. The needs of each group are different and can be optimally addressed using different AR modalities. The use of laser-generated line graphics was deployed as a means of projecting messages and notifications to humans in the vicinity. This is perceived as supporting a safer working environment that humans and robots can share. In addition, humans are also enabled with a better awareness of the robot's actions and this reduces the possibility of accidents. The behaviour of humans avoiding the robot's workspace, where such options exist, produces opportunities for faster platform speeds and improved task efficien‐ cies.

Mobile robots should indicate its intension as it executes its task to humans in its vicinity. This is a necessary requirement when the general public and mobile robots share and intrude into the workspace of the other. In recent times, we witness the deployment of automated trans‐ portation of food items in restaurants and of humans in autonomous vehicles. These are deployments in shared environments. The issues highlighted are relevant and worthy of consideration in their design and implementation. The laser writer provides a simple and effective way to improve on passerby situation awareness in a naturally bright environment.
