# Analysis of motion characteristics and dynamic modeling of traction machine brakes stopping car

## TL;DR

This paper improves elevator safety by analyzing braking dynamics and developing a new model to accurately predict elevator car stopping behavior.

## Contribution

A novel differential equation model is proposed to capture elevator car braking dynamics with nonlinear sealing and braking torques.

## Key findings

- The new model accounts for rope slip and asynchronous motion during braking.
- Theoretical results align closely with experimental data, showing improved accuracy.
- The model has significant potential for engineering applications in elevator safety.

## Abstract

Braking distance is one of the important indicators for measuring elevator safety. At present, using the traction machine brakes to stop the traction sheave and indirectly stop the car is the mainstream stopping method for elevators with gearless machine. However, in existing theoretical research, the complex elevator braking process is only modeled through simple constant acceleration motion, without considering the influence of the sealing device, let alone the sliding motion of the suspension ropes on the traction sheave after the traction sheave stops rotating, the calculated results are much smaller than the actual situation, which poses a huge challenge to the safe operation of the elevator. Therefore, this article analyzes the slip dynamics characteristics of the suspension ropes on the traction sheave and the asynchronous operation characteristics of traction shave and car during the car braking process under the influence of nonlinear sealing torque and braking torque. A new differential equation for acceleration, velocity, and displacement of the car is established, and the equation is solved through approximate methods. The experimental results show that the theoretical model proposed in this paper can accurately evaluate the dynamic characteristics of the car braking process and has wide engineering application value.