Research on dual-wheel-independent-drive control of electric forklift based on optimal slip ratio

Sci Prog. 2020 Jul-Sep;103(3):36850420927836. doi: 10.1177/0036850420927836.

Abstract

Introduction: As an important transportation, the research on the control strategy of forklift has not been widely carried out.

Objectives: This article proposes a turning slip regulation control strategy, which includes the improved electronic differential velocity control and turning slip regulation control, to track the optimal slip ratio.

Methods: First, combined with the basic structure and characteristics of dual-wheel-independent-drive electric forklift, the vehicle model, Ackermann-Jeantand steering model, tire-ground model, and tire model of the driving wheel are established respectively. Second, according to these models, an improved electronic differential control strategy considering the influence of vertical load on tire force is proposed and it can reasonably allocate the driving torque of the two driving wheels of electric forklift. Moreover, the optimal slip ratio is given out and the turning slip regulation control strategy, which can track the optimal slip ratio of electric forklift under the conditions of different road surfaces is designed.

Results: The simulation result and vehicle test show that the control strategy can optimize the slip ratio of electric forklift and greatly improve the stability of electric forklift.

Conclusion: The turning slip regulation control strategy can be implemented on the TFC35 forklift to improve the safety and stability.

Keywords: DWID forklift; TSR; electronic differential control strategy; extremum-seeking algorithm; slip ratio.