# Distance Assessment by Object Detection--For Visually Impaired Assistive Mechatronic System
###### Abstract
Some of the devices have already been the subject of government assistance programs in Romania, and some programs allow visually impaired people to purchase such devices with a subsidy in the form of a support voucher after their medical documents have been examined by a medical commission. The devices belong to different categories, including smart canes or white canes and portable devices that can be attached to the frame of the user's glasses. This article presents the research concept and the results of the distance assessment of a new, customized object detection and recognition technique. The first approach is a new method based on low-cost photo cameras (from a mobile phone) used for special sign detection and distance assessment. This method is intended to  
Figure 1: VIPs-Walker design (virtual prototype): (**a**) walker with its robotic arm outstretched to grab an object; (**b**) walker on the stairs. be available for ordinary visually impaired people who, most of the time, do not have a good financial situation. Another focus of first approach includes the implementation in applications for surgical robots. Surgery that is coordinated and assisted by robotics is also a reality today. Observing areas undergoing treatment, recognizing areas between organs and areas affected by various types of disease, and measuring the size of and distance between tissues inside the body using non-invasive methods represent important requirements for metchronic systems used in the medical field. Through high-performance visualization systems, with the possibility of presentation through augmented reality, colorists, transparency, sectioning, focusing, contrast, etc., robotic systems have acquired a new sense of environmental perception [1; 2; 3]. The second approach is based on an RPLIDAR sensor and HQ camera, designed to work as an innovative hardware subsystem, which enables fast and accurate object recognition as well as high-precision distance measurement. Because of its high-performance components, this system is relatively expensive, but stands as a very good solution when high-precision results need to be obtained. The system designed for this research is an innovative mobile robotic platform equipped with an HQ monocular visual subsystem, LIDAR-type scanning sensor (\"light detection and ranging\" or \"laser imaging, detection and ranging\") and a Jetson Nano development kit. This structure can obtain extra and fast information and accurate knowledge of the environment, as well as the recognition of its objects, facilitating the execution of the necessary motions in safe conditions. At the time of this research, no studies were identified in the specific literature that included the hardware combination of the Raspberry Pi HQ camera with an IMX477 sensor and the RPLIDAR A3 scanner. The results obtained (experimentally) by each of the abovementioned items can be used for the elaboration of the strategies for the motion control of mechatronic systems used in healthcare and assistive living, specifically the robotic arm of the VIPs-Walker. This paper is structured as follows. Section 2 outlines a review of some recent research on mechatronic structures, methods, algorithms, and perceptual equipment. Section 3 highlights the materials and methods used. Section 4 provides information on the experimental results obtained in the real environment and the results of the simulation of the motion of the VIPs-Walker arm in order to evaluate the strategy and dynamics of grabbing an object. The final part of the article presents discussions and observations on the methods and equipment used in Section 5, as well as the conclusions of the research in Section 6.