Power-assisted Bicycle Torque Sensor Design And Control Algorithm Design

Electric Power Assisted Bicycle(EPAC),a new green transport,has a huge environmental value and broad market prospects.EPAC can detect the size of pedal force in real-time.The intelligent controller can adjust the size of the driving torque,so that the rider can get a more comfortable riding experience.Torque sensor is the core component of Electric Power Assisted Bicycle,which is able to detect the signal of change of pedal force.At present,torque sensors of EPAC are generally designed to be quite complicated,whose price are expensive.So this paper will design a compact,low cost integrated torque sensor based on the Hall sensor.The main work will be described in the following:1.This paper presents a measurement method of the pedaling force for the EPAC based on the principle of chain force,and designs a torque sensor mechanism according to the principle.Based on the existing EPAC model,the installation plan and parameters of the torque sensor are determined.Through force analysis and dynamics analysis,the relationship between sensor position and pedal is derived.2.According to the layout of the program,a new type of integrated torque sensor with a motor and the torque sensor is designed.The main components of the integrated torque sensor include a motor,a deceleration gear,a power assisted sprocket and an flexible device,and this paper gives the specific design process..3.In order to EPAC can be able to achieve better adaptability in different load and road slope,this paper proposes a new control approach adaptive to load and road slope for EPAC based on disturbance observers.The controller detects the speed signal and the pedal force signal,and analyzes the corresponding change rule,estimates the road slope and the load.And the controller adjusts the motor power,which makes rider can keep riding effortlessly in load and upslope,so that riding experience is better.In the paper,the feasibility of the algorithm is verified by co-simulation.All parameters are determined,by changing the control parameter adjustment rules examine the performance.The results of co-simulation demonstrates that the proposed control approach is highly effective in various riding conditions.In extreme conditions,the control system still has good robustness.4.At last,power-assisted bicycle experiment platform was developed.Experiment show that the principle of power-assisted is feasible and effective.The ride experience validated the accuracy of the experiment,in the outdoors.