Vehicle with electric motor
First Claim
1. An electric power assisted vehicle comprised of at least one propulsion device, a manual power device for driving said propulsion device, an electric motor for driving said propulsion device, a control for controlling the power applied by said electric motor for driving said propulsion device, a vehicle speed sensor for sensing the speed at which said vehicle is driven, a force sensor for sensing the force applied to said manual power device, said control establishing a predetermined force which must be sensed by said force sensor before electric power assist will be supplied by said electric motor, means for comparing the speed of said vehicle sensed by said speed sensor with a predetermined vehicle speed when said predetermined force is applied, and means for precluding the application of electric power assist unless said predetermined vehicle speed is exceeded.
1 Assignment
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Accused Products
Abstract
An electrically powered vehicle wherein the electric power may be provided by an auxiliary electric motor with power assist being determined by a manual force applied by an operator for manually propelling the vehicle. The vehicle control includes a method for determining when the vehicle is being started from a stop and for providing a gradual application of electric power assist during such start-up. In addition, if the operator calls for an abrupt change in power assist, the actual power assist is applied only gradually to provide smoother operation. The system also has self-checking functions and the electric power assist is disabled in response to certain types of failures. However, the operator is warned in advance that the power will be shut down so as to avoid emergency situations. The self-checking provides an arrangement for checking when the speed sensor is inoperative by sensing certain output characteristics of the speed sensor and the force application. In addition, the device precludes the application of electric power assist under conditions when the battery might be depleted and when the vehicle is not actually moving. Various arrangements are provided for also checking the output of the battery and precluding power assist or controlling the power assist, depending upon the state of the battery. In addition, the vehicle may include other electrical accessories, and these are powered by an auxiliary battery. The auxiliary battery, however, may be charged from the main battery.
188 Citations
47 Claims
- 1. An electric power assisted vehicle comprised of at least one propulsion device, a manual power device for driving said propulsion device, an electric motor for driving said propulsion device, a control for controlling the power applied by said electric motor for driving said propulsion device, a vehicle speed sensor for sensing the speed at which said vehicle is driven, a force sensor for sensing the force applied to said manual power device, said control establishing a predetermined force which must be sensed by said force sensor before electric power assist will be supplied by said electric motor, means for comparing the speed of said vehicle sensed by said speed sensor with a predetermined vehicle speed when said predetermined force is applied, and means for precluding the application of electric power assist unless said predetermined vehicle speed is exceeded.
Specification