Patents Assigned to El-Forest AB
  • Patent number: 8649927
    Abstract: A method of controlling operation of an energy system for a hybrid vehicle, the energy system including a combustion engine controlled to work at a desired engine rotational speed; an electric generator/motor driven by the combustion engine to output a generated electric power; a power consuming device driven by the combustion engine and drivable by the electric generator/motor; and an energy storage device connected to the electric generator/motor and arranged to receive the generated electric power output by the electric generator/motor. The method includes the steps of: monitoring an actual engine rotational speed; and if the actual engine rotational speed decreases from the desired engine rotational speed, controlling the electric generator/motor to output a gradually reducing generated electric power. Hereby, the combustion engine can be allowed to remain in an operating range where it works efficiently, while at the same time fulfilling the need for power of the power consuming device.
    Type: Grant
    Filed: May 12, 2009
    Date of Patent: February 11, 2014
    Assignee: El-Forest AB
    Inventor: Roger Gustavsson
  • Publication number: 20120072076
    Abstract: A hybrid utility vehicle has a vehicle body and at least first and second driving wheels, each driving wheel has two wheels provided on opposite sides of the vehicle. Each of the wheels is drivable by a drive unit, whereby the speed of each wheel may be adjusted independently of the speed of the other wheels, thereby enabling adjustment of the relative position between a wheel of the first set of driving wheels (5a-b, 5e-f) and a wheel of the second set of driving wheels, and wherein the vehicle further has at least one actuator for enabling adjustment of the relative position between the first set of driving wheels and the second set of driving wheels. A method and control unit for control of the vehicle are also disclosed.
    Type: Application
    Filed: May 29, 2009
    Publication date: March 22, 2012
    Applicant: EL-FOREST AB
    Inventor: Roger Gustavsson
  • Publication number: 20120053773
    Abstract: A method of controlling operation of an energy system for a hybrid vehicle, the energy system including a combustion engine controlled to work at a desired engine rotational speed; an electric generator/motor driven by the combustion engine to output a generated electric power; a power consuming device driven by the combustion engine and drivable by the electric generator/motor; and an energy storage device connected to the electric generator/motor and arranged to receive the generated electric power output by the electric generator/motor. The method includes the steps of: monitoring an actual engine rotational speed; and if the actual engine rotational speed decreases from the desired engine rotational speed, controlling the electric generator/motor to output a gradually reducing generated electric power. Hereby, the combustion engine can be allowed to remain in an operating range where it works efficiently, while at the same time fulfilling the need for power of the power consuming device.
    Type: Application
    Filed: May 12, 2009
    Publication date: March 1, 2012
    Applicant: EL-FOREST AB
    Inventor: Roger Gustavsson
  • Patent number: 7798262
    Abstract: A vehicle has at least three drive axles each with a pair of drive wheels, a steering system that directly controls the steering angle between at least two of the drive axles. The vehicle is arranged so that all drive wheels on its right hand side and left hand side, respectively, essentially follow the same wheel tracks when it is driven. The frequency of rotation is individually controllable for each drive wheel. The vehicle includes differential compensating elements arranged to register the relative steering angle for each consecutive pair of drive axles, respectively, and the mutual frequency of rotation for the drive wheels of each drive axle is controlled by the registered relative steering angle associated with the axle. A drive axle arrangement for such a vehicle is also disclosed.
    Type: Grant
    Filed: November 12, 2007
    Date of Patent: September 21, 2010
    Assignee: El-Forest AB
    Inventor: Lennart Lundström