Strategy for longitudinal guidance of a motor vehicle using a crank mechanism

Abstract

The patent describes an electrical connection between a crank mechanism with an active actuator and the active actuator on the vehicle. This results in considerable design freedom for the input and feedback synthesis, which links the mechanical and electrical parameters of the actuators. The present patent describes a novel operating concept and ultimately a new driving experience for vehicles operated via a crank mechanism. Complex functions between the driver input at the crank mechanism and the outputs of the overall system at the actuators simplify operation and make it more intuitive. Furthermore, two application purposes are described that are only made possible by the system architecture in combination with suitable strategies. This allows for the realization of new application scenarios.

Description

[0001] The invention relates to a strategy for longitudinal guidance of a motor vehicle by means of a crank mechanism (1). The vehicle is operated by a rotary movement of the crank mechanism without limiting the angle of rotation φ. KT,ist The movement is assigned a torque identifier. This necessitates a target value, which must be determined by a strategy.

[0002] To represent an identifier, the crank mechanism (1) is connected to an actuator, which is actively controlled by a feedback synthesis strategy (3). The control of the actuator's controller on the crank mechanism is achieved by specifying a setpoint value for the torque M. KT,soll , the angular velocity ω KT,soll , or the angular position φ KT,soll of the actuator. The height of the setpoint is determined depending on the vehicle speed v. Fzg,ist and other possible sizes.

[0003] From the state variables MKT,ist , ω KT,ist , φ KT,ist of the crank mechanism, as well as other possible parameters, a torque specification M is used in the strategy for preset synthesis (4). Fzg,soll derived for the vehicle's actuating element, usually one or more drive motors.

[0004] The crank mechanism is operated by a directed force. Consequently, the lever arm relative to the crank's axis of rotation varies as a function of the crank mechanism angle φ. KT,ist This results in an alternating torque M. KT,ist , as described in EP 1 165 188 B1. To compensate for this effect, it is advisable to use a lower setting when the crankshaft is stationary or operating at low speeds and the vehicle is traveling at low speeds. Fzg.ist , the angular position φ KT,soll to keep the crank mechanism constant within the range of a large lever arm of the operating force.

[0005] With the crank drive in a fixed angular position at standstill, changing the direction of travel from standstill can advantageously be achieved without an additional control element for setting the direction of travel. This relationship is explained in Fig. shown. With increasing vehicle speed v Fzg.ist A variable angular velocity ω is used. KT,soll instead of a fixed value for φ KT,soll This strategy offers the advantage of fixed pedal positions at low speeds, for example during shunting, which ensures a constant lever arm and thus better control. For instance, this makes it easier for the driver to maintain a consistent vehicle position when stationary, on inclines or declines.

[0006] To avoid specifying unfavorable angular positions φ KT,soll With a short lever arm, the angular position φ can be KT,istof the crankshaft drive (1) can be detected. By specifying a small torque M KT,soll A rotation into a more suitable position may be possible.

[0007] There is no sensor for determining the angular position φ KT,ist If installed, the procedure can alternatively be activated when the vehicle's service brake is applied. When stationary, it is advisable to enter the target torque M in the target synthesis (3). Fzg,soll to set to zero. This corresponds to the behavior of an open clutch in a conventional vehicle. In this case, the input variable generated in the feedback synthesis (1) for the crankshaft drive does not depend on the vehicle size v. Fzg.ist Instead, this is determined based on the state of the crank mechanism, for example the angular position φ. KT,istdetermined. This strategy enables, among other things, the generation of drive energy for the vehicle (2), provided that the actuating element on the crank drive (1) has the possibility of generator operation.

[0008] It is possible to adjust the usable angle range φ KT,ist of the crankshaft drive by specifying a high torque value M KT,soll to restrict movement against the direction of motion. This replicates the behavior of a conventional pedal operation. In the case of a proportional relationship M KT,soll = φ ∗ M KT,c The behavior is similar to that of a mechanical torsion spring. This allows for intuitive operation in accordance with state-of-the-art accelerator pedal units, without the need to apply large amounts of energy and power during unlimited rotational movement.

[0009] If the actuators used have a continuous overload mode as well as a time-limited overload mode, then the determination of M Fzg,soll The value is adjusted to the time-varying performance of the actuators. If the actuator on the crank drive is overloaded, the value is increased so that a lower torque M is required. KT,ist This is necessary for operation. This ensures better utilization of the actuator's currently available operating range. This prevents inconsistencies in operation when switching between continuous and overload operation. Furthermore, it enables actuators to be dimensioned according to requirements.

[0010] Does the power P determined at the crank mechanism (1) serve KT,ist = ω KT,ist * M KT,istIf the performance of the actuator in the vehicle (2) is directly proportional to the specified power output, it is possible to compete with several vehicles with the same proportional factor. This exhibits characteristics of cycling and motorsports, as the physical power output is determined in conjunction with the skill in longitudinal vehicle control.

[0011] The strategy described in

[0010] can be used at standstill and low speeds v Fzg.ist with a proportional coupling of the position of the crank mechanism φ KT,soll with the position of the actuating element φ Fzg,istin the vehicle (2). This enables feedback synthesis (3) based on the position of the driven wheels. Compared to the prior art for longitudinal guidance with angle-limited pedal assemblies, this is advantageous because the longitudinal slip of the drive wheels can be directly inferred from the crank mechanism (1). The longitudinal slip correlates with the longitudinal force in the tire contact patch. Consequently, vehicle operation can be advantageously controlled by metering the input torque M. KT,ist This is done at the crank mechanism. The Fig. This shows an example of the arrangement of the components of the control element. (57) Main claim:

[0012] The invention relates to strategies for the longitudinal guidance of a motor vehicle by means of a crank mechanism. The crank mechanism replaces the prior art pedal assembly for longitudinal vehicle guidance, consisting of separate, rotatably mounted, angle-limited accelerator, brake, and clutch pedals.

[0013] This assembly has stored identifiers, describable by the restoring torque as a function of the actuation angle. The restoring torque results from the design of passive elements (e.g., a torsion spring), the characteristics of the actuated system (e.g., the brake hydraulics), or synthesized feedback based on active systems (e.g., an active actuator). A crank mechanism instead of the usual pedal mechanism allows for an unlimited angular range and actuation in both directions of rotation. The identifier of the crank mechanism can be actively imposed by an actuating element (1). This necessitates a suitable strategy for the specification synthesis (4) to determine the torque specification M. Fzg,soll to the vehicle's actuator (2) and for feedback synthesis (3) to the actuator of the crank drive (1). Strategies are known from the prior art which determine the target value M Fzg,soll for the control of the actuator in the vehicle proportional to the torque M applied to the crank mechanism KT,ist determine. The synthesis of the feedback via the actuator on the crank mechanism is determined there via one of the vehicle speed v. Fzg.ist proportional rotational speed setting ω KT,soll The crank mechanism is implemented here. This is where the invention comes in and describes advantageous extensions of this strategy. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] EP 1 165 188 B1

[0004]

Claims

[1] Strategy for longitudinal guidance of a vehicle (2) by means of a crank mechanism (1), characterized by , that the crank mechanism (1) by specifying an angle φ KT,soll at low speeds v Fzg,ist is held at a fixed value. The speed v exceeds Fzg,ist If a positive threshold is exceeded or a negative threshold is undershot, the value of the target angle φ is changed. KT,soll Variable values ​​are specified. [2] Strategy according to claim 1, characterized by that the direction of travel at standstill is determined by the direction of the applied torque M KT,ist This is achieved. Stepless reversing is possible without an additional control element. [3] Strategy according to claim 1, characterized by that the activation of the service brake is detected. In the event of activation, the specified value M is set. Fzg,sollThe input signal to the actuator in the vehicle (2) is set to zero. The input signal to the actuator of the crank drive (1) is directed opposite to the direction of rotation, resulting in regenerative operation. [4] Strategy for longitudinal guidance of a vehicle (2) by means of a crank mechanism (1), characterized by , that the specification for the actuator M KT,soll at the crank mechanism in proportional dependence on the angular position of the crank mechanism φ KT,ist is determined. [5] Strategy for longitudinal guidance of a vehicle (2) by means of a crank mechanism (1), characterized by , that the predefined synthesis determines the predefined moment for the vehicle M Fzg,soll increased if the actuating element on the crank drive (1) is in a performance-degraded state. [6] Strategy for longitudinal guidance of a vehicle (2) by means of a crank mechanism (1), characterized by , that the power of the crankshaft drive P KT,ist = ω KT,ist * M KT,istand the performance of the actuator in the vehicle is in a fixed ratio. Furthermore, this strategy is used in the same way for several vehicles within the context of a competition. [7] Strategy according to claim 6, characterized by , that the rotational position of the crank mechanism (1) φ KT,soll and the position of the actuator φ Fzg,ist in the vehicle (2) at least at the time of starting off, in a fixed ratio.

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