Real-time mass estimation of electric vehicles
Connection and control concepts for real-time mass estimation of an electric vehicle are provided. The vehicle comprises a vehicle control module (VCM). Further, the vehicle comprises an inverter coupled to the VCM, and an electric motor coupled to the inverter. The electric motor is configured to measure the torque output from one or more wheels of the vehicle. The VCM is configured to receive the torque output measured by the electric motor and estimate mass of the vehicle based on the received torque output.
1 . A method of estimating a mass of an electric vehicle (EV), the method comprising:
receiving a torque output of one or more wheels of the EV from an electric motor of the EV;
determining if the EV is in motion; and
estimating the mass of the EV based on the torque output received from the electric motor,
wherein, when the EV is in motion, the mass is estimated using a system identification approach based on the torque output received from the electric motor of the EV,
wherein estimating the mass using the system identification approach comprises injecting predesigned inputs into a mass estimation system of the EV, and
wherein injecting predesigned inputs into the mass estimation system of the EV comprises:
determining, based on a user input, if it is safe to perform mass estimation for the EV; and
when the user input indicates that it is safe to perform mass estimation, injecting the predesigned inputs into the mass estimation system.
2 . The method of claim 1 , wherein, when the user input indicates it is not safe to perform mass estimation, allowing a defined amount of time to pass.
3 . The method of claim 1 , wherein injecting predesigned inputs into the mass estimation system comprises injecting a pseudo random binary sequence (PRBS) signal.
4 . The method of claim 1 , further comprising storing results of the mass in a memory.
5 . A method of estimating a mass of an electric vehicle (EV), the method comprising:
receiving a torque output of one or more wheels of the EV from an electric motor of the EV;
determining if the EV is in motion; and
estimating the mass of the EV based on the torque output received from the electric motor,
wherein, when the EV is in motion, the mass is estimated using a system identification approach based on the torque output received from the electric motor of the EV,
wherein estimating the mass using the system identification approach comprises injecting predesigned inputs into a mass estimation system of the EV, and
wherein injecting predesigned inputs into the mass estimation system comprises injecting a pseudo random binary sequence (PRBS) signal.
6 . A method of estimating a mass of an electric vehicle (EV), the method comprising:
receiving a torque output of one or more wheels of the EV from an electric motor of the EV;
determining if the EV is in motion; and
estimating the mass of the EV based on the torque output received from the electric motor,
wherein, when the EV is in motion, the mass is estimated using a system identification approach based on the torque output received from the electric motor of the EV,
wherein estimating the mass using the system identification approach comprises utilizing a pedal input from a user over a persistency of excitation (PE) time period, and
wherein the PE time period correlates to an amount of time within a margin for error.
7 . The method of claim 6 , wherein the amount of time is between 5 and 20 minutes and the margin for error is between 0 and 5 percent.