Patent ID: 8909411

Claim:
A detection system for detection of a slip rate of a DC motor driven electric vehicle, comprising a motor rotational speed detection unit, a motor voltage detection unit, and a motor current detection unit, all of which are connected with a drive motor; wherein, said motor rotational speed detection unit, said motor voltage detection unit, and said motor current detection unit are connected with a slip rate calculation unit by means of a motor rotational speed signal processing unit, a voltage signal processing unit, and a current signal processing unit, respectively; and said slip rate calculation unit is configured with a slip rate calculation formula, wherein the detection system is programmed to perform a slip rate detection method comprising the following steps: (1) measuring, using the motor voltage detection unit, the motor current detection unit, and the motor rotational speed detection unit, respectively, voltage, current, and rotational speed of the drive motor to obtain armature voltage U a , armature current i a , and motor rotational speed ω m of said drive motor; (2) obtaining motor coefficients of said drive motor, wherein the motor coefficients comprise motor inductance L a , armature resistance R a , motor torque coefficient k m , and motor back electromotive force coefficient k e ; (3) obtaining vehicle constants, wherein the vehicle constants comprise vehicle mass M, wheel radius r, wheel rotational inertia J, and transmission ratio a; and (4) obtaining the slip rate according to the slip rate calculation formula shown below: λ ⁡ ( t 2 ) = ( 1 + J r 2 ⁢ M ) [ 1 - ω m ⁡ ( t 1 ) ω m ⁡ ( t 2 ) ] - a 2 · k m r 2 ⁢ MR a ⁢ ω m ⁡ ( t 2 ) ⁢ { ∫ t ⁢ ⁢ 1 t ⁢ ⁢ 2 ⁢ U a ⁢ ⅆ t - k e ⁢ ∫ t ⁢ ⁢ 1 t ⁢ ⁢ 2 ⁢ ω m ⁢ ⅆ t - L a · [ i a ⁡ ( t 2 ) - i a ⁡ ( t 1 ) ] } + λ ⁡ ( t 1 ) ⁢ ω m ⁡ ( t 1 ) ω m ⁡ ( t 2 ) wherein, t 1 is a first measurement time; t 2 is a second measurement time; and λ is the slip rate.