Preprogrammed Multiway Workbench- An experimental study using ultrasonic sensors with the help of microcontroller

This study aims to find the ultimate solution for the table to be used by different kinds of people, such as a healthy kid, young, old, and physically disabled. People face problems while using the table of inappropriate height. Especially, physically disabled people are unable to cope with healthy while doing regular work due to height constraints. Using a human-centered design approach, the authors create a design process based on field research and catering to local needs to develop a suitable product for users in a developing country. So, the authors introduced a table, which has a motorized height adjusting mechanism. Ultrasonic sensors detect the user’s height and height of the table adjusted as per the height of the user.


Introduction
An adjustable table is now a desperate need for humankind. Several adjustable height tables are in existence but still are unable to achieve the ultimate goal. The authors surveyed a small village where people with different needs responded when asked about tables. The most common issues that people talked about were storage facilities portability, and a table for everyone. According to Osmo Hänninen and Reijo Koskelo [1], Z. Zarith Afzan [2] the traditional tables made students use a similar height of the table. Tables and chairs were all alike for all types of students, especially tricky for taller and shorter students to work. When used adjustable desks and chairs, postures became much better. Many researchers have designed tables and chairs differently, keeping in mind the need of students such as Kashif and others [3], Samira Ansari [4]. The same case applied to all age groups (old, kid, young) of humanity. The height of desks and chairs plays a vital role in people's life. The neck, back, and shoulder problems have already discussed by many researchers earlier. Available tables have been developed specifically for height-adjustable tops. Known tables have a mechanical structure which permits table tops to be manually height-adjusted. Such a table requires a human's power to transmit the required power to operate a table. Other known tables employ powered electric drivers, but generally, a single motor provided for each height-adjustable tabletop. Although these known arrangements have provided the ability to adjust the height of the table independently, yet their complex mechanical structures suggested by Staude, E.G. [5] made it more difficult than desired.
Also, in health care institutions, as mentioned by Berg, Nels O., and Abraham M. Budnick [6] there is some mechanism to adjust the height of the top, still unable to achieve the desired goal. Keeping in mind such needs, several researchers designed tables differently, such as Birdsall [7]. Some related 2 problems are small menses and apartments that have adequate furniture, especially suitable for the many Junctions. Among the items of furniture, next to the tables required for a meal, the tea/coffee, are almost universally standard for the modern home. Due to essential needs, they have to cramp their living quarters or overload their storage space. Authors focused on all these problems and designed a workbench to remove drawbacks that other desks failed to do so. The author's design offers an adjustable tabletop without the requirement for external human resources, portability with the sense of tires, storage utilizing drawers, easy to use as an automatic workbench. Ultrasonic Sensor patented by Reebs, Stephen R. [8] has a wide range of applications. But in this project, authors used this as a height detecting device. Ultrasonic speakers are the two-round looking component. One transmits a 40Hz sound wave that reflects from a solid surface, and another one detects the reflected sound wave. The total time taken is measured, and hence, we can measure the distance of the object. This application is used to measure the height of the user. DC motor by K. T. Chau et al. [9] is used to change the height of the desk. It works on the principle "whenever a current-carrying conductor placed in a magnetic field, it experiences a mechanical force." Motor driver amplifies a low current signal to a high current signal. The L298D Xu-Cai [10] is a typical Motor driver that drives 2 DC motors simultaneously. The driver feeds electricity into the engine in variable amounts, also variable frequencies that help in controlling the speed and torque of an automobile. A few more designs and researches by Reetu Malhotra [12] - [16] were taken into consideration.
An open-source electronics platform, i.e., Arduino used which is easy to use both in terms of hardware as well as software. Arduino widely used for projects and experiments. Software and project equipment connected through this software. The set of instructions makes the controller do whatever we want. Here Arduino operates motor-driver, motors (in connection with driver), and ultrasonic sensors with a set of instructions. Rack and Pinion by Joerg [11] is a type of linear actuator that has a circular gear with straight gear. The pinion drives rotation, which makes the rack moves linearly and vice versa. This actuator is a kind of link between the motor and the tabletop, which makes the variable height possible.

Methodology
A height-adjustable workbench disclosed. The workbench includes a fixed surface, an adjustable surface configured to move upwards and downwards in a plane perpendicular to the fixed surface. A set of linear actuators coupled to the fixed surface and the adjustable surface to facilitate the upward and downward movement of the adjustable surface. Also, a set of rotary devices coupled to the set of linear actuators. The rotary device configured to rotate selectively in clockwise and anticlockwise directions to move the adjustable surface in the upward and downward directions. When the rotary device rotates in a clockwise direction, the adjustable surface moves away from the fixed surface. When the rotary device rotates in an anticlockwise direction, the adjustable surface moves towards the fixed surface. The first set of sensors coupled to the adjustable surface and configured to sense one or more parameters associated with the height of a user. A control unit operatively coupled to the first set of sensors and the set of rotary devices. The control unit configured to compare the sensed one or more parameters with a dataset comprising predefined one or more parameters. It generates a height adjusting signal based on the comparison, and transmit the generated height adjusting signal to the set of rotary devices. Based on receipt of the height adjusting signal, the set of rotary devices rotates selectively in a clockwise or anticlockwise direction to adjust the distance between the adjustable surface and the fixed surface. The top of the 3 the further motor connected with pinion. Rack and pinion are in the constant connection that lets us adjust the height of the top cover. Motors powered with the help of a dc motor driver, which further connected to a single battery. Motion and speed of motors are controlled using a connection from motor driver to Arduino. Ultrasonic Sensors located at the top of the table. It senses the height of the user. Ultrasonic sensors gave input to Arduino as the height of the user, and programmed Arduino allows the rotation of the motor until the required height attained. Installed tires let us to the port table anywhere and anywhere.

Description of the Model:
Front view and different components of the adjustable height table shown in Figure 1.   . 7) used to increase the length and width of the table in case of more users or in case the user wants to keep more items. An adjustable tabletop (component no.8) adjusted as per the need of the user. Lamps and ultrasonic sensors fixed at a certain height of this particular base. Tires are installed in component no. 9 so that the user may take it anywhere and everywhere without much difficulty. Some table lights exist (shown in component no.10) to provide the user an easy to work comfortably in the dark as well. Lamps could be powered externally or using the battery used to power the motors.

Benefits over previous models of workbench:
x The proposed table provides an automatic height adjustable workbench, the height of the workbench adjusted after sensing the height of the user. x It provides a set of switches to adjust the height of the workbench in the upward and downward direction. x This design provides an automatic height adjustable workbench, and the user can comfortably use the workbench for sitting as well as standing work. x It provides a cost-effective and straightforward automatic height adjustable workbench.
x It provides a precise and time-efficient automatic height adjustable workbench.