# Distance Assessment by Object Detection--For Visually Impaired Assistive Mechatronic System
###### Abstract  
Techniques for the detection and recognition of objects have experienced continuous development over recent years, as their application and benefits are so very obvious. Whether they are involved in driving a car, environment surveillance and security, or assistive living for people with different disabilities, not to mention advanced robotic surgery, these techniques are almost indispensable. This article presents the research results of a distance assessment using object detection and recognition techniques. The first is a new technique based on low-cost photo cameras and special sign detection. The second is a classic approach based on a LIDAR sensor and an HQ photo camera. Its novelty, in this case, consists of the concept and prototype of the hardware subsystem for high-precision distance measurement, as well as fast and accurate object recognition. The experimentally obtained results are used for the motion control strategy (directional inverse kinematics) of the robotic arm (virtual prototype) component in special assistive devices designed for visually impaired persons. The advantages of the original technical solution, experimentally validated by a prototype system with modern equipment, are the precision and the short time required for the identification and recognition of objects at relatively short distances. The research results obtained, in both the real and virtual experiments, stand as a basis for the further development of the visually impaired memoratric system prototype using additional ultrasonic sensors, stereoscopic or multiple cameras, and the implementation of machine-learning models for safety-critical tasks. distance assessment; object detection; mobile mechatronic systems; visually impaired person; path planning; surgical robots +
Footnote †: journal: Applied  
0000-0001-9993-3400-3400][PERSON]  
0000-0001-9993-34  
People with visual impairments, in addition to moving in closed or open spaces, need to carry out daily activities that, in most cases, require the recognition of environmental objects. Some issues need to be taken into account when it comes to integrating visually impaired people into society. The participation of people with visual disabilities in social life means creating a specific framework and appropriate devices (devices specific to the activities carried out and equipped with sensors that allow data collection for spatial orientation, object recognition, location, etc.) that would enable them to carry out activities similar to those of any other person with no disabilities. This is one of the reasons why environmental recognition applications have entered the field of assistive systems for visually impaired persons (VIPs). VIPs are oriented, aided by technology, towards a more complete and accurate understanding of the environment, obtaining new abilities to communicate properly with other people. The concept and design (by the authors) of a special device aimed to assist VIPs with their mobility are shown in Figure 1. The device enables the user to detect and grab objects and avoid obstacles, and provides guidance when the user walks down alleys and narrow spaces, as well as when climbing the stairs (up and down). In this study, the device is called a VIPs-Walker. The VIPs-Walker system is designed as a modular structure (with a voice assistance module and a haptic module), and is intended to be used by both visually impaired people and those with multiple disabilities (stability issues that require support while walking). The user's comfort is enhanced by the device's motion system (electric motor), as the VIP only needs to follow the device and its feedback. In recent years, various studies have focused on devices with applications for choosing the correct routes using GPS coordination, assessing distances from objects met on the road, detecting and recognizing objects in front of the device, etc.