Dr. Ing. H.c. F. Porsche Aktiengesellschaft

Patric Lardy

Joseph Petersmann

Willi Seidel

Heinz Stehle

Axel Richter

Ulrich Schempp

Herbert Glueck

The invention provides a method and apparatus for controlling a continuously variable speed transmission of a motor vehicle driven by an internal-combustion engine, by means of a control arrangement having a selecting device which simulates a stepped transmission by adjusting transmission ratios in according to a group of preset transmission ratios. To prevent repeated up and down shifting, a control arrangement is provided with a unit for detecting driving situations in which a transmission ratio shift according to the preset transmission rations would be too large, and also a unit for adjusting the preset transmission ratio. The recognition unit activates the adjustment unit as soon as the above-described driving situation occurs, and the adjustment unit then changes a preset transmission ratio so that the motive force is adapted to the present motive resistance, allowing the vehicle to achieve a positive longitudinal acceleration.

Process and apparatus for controlling a continuously variable speed

A control system and process for an infinitely variable transmission which has a first operating mode which automatically selects the transmission ratio, and a second operating mode in which the transmission ratio can be selected directly by the driver. According to the invention, the degree of damping effective during the adjustment of the transmission ratio is adjusted in response to the selected operating mode. In the automatic operating mode, a high degree of damping is used, while in the manual operating mode, a lower degree of damping is provided.

Control system and control process for an infinitely variable

The invention relates to a process for controlling a change of the transmission ratio (ue) in an infinitely variable transmission, which simulates a stepped transmission. A basic shifting time is determined separately for each shifting position and direction. In addition, a rotational speed factor, is used to take into account the change of the rotational input speed of the transmission caused by the change of the transmission ratio, and a lead factor reflects the lead existing at the transmission input. Shifting of the infinitely variable transmission is then performed as a function of the basic shifting time, the rotational speed factor and the lead factor.

Process for determining the shifting time for a transmission ratio

This invention provides a method and apparatus for controlling a continuously variable speed transmission connected with an internal-combustion engine according to one or several characteristic control curves. A transmission ratio of the transmission is automatically set according to the position of a power control element. In order to be able to operate the internal-combustion at its consumption-optimal point, a 'constant driving method' which requires only a low reserve of tractive force is detected, and transmission ratio is adjusted in response thereto, so that the internal-combustion engine is operated in its point of the lowest specific fuel consumption for the existing operating point of the vehicle.

Control process and control arrangement for a continuously variable

An arrangement for the recognition of misfirings of internal combustion engines with externally supplied ignition in which for the recognition of misfirings, the cylinders are combined into two groups and an ignition system of its own is coordinated to each group; a thermo-element is thereby arranged in the exhaust tract of a cylinder of each group. A pair of thermo-elements is series-connected in opposite polarity and the resulting thermo-voltage at the free ends is monitored by means of two threshold circuits. From the amount and sign of the resulting thermo-voltage, a defective ignition system can be determined and the corresponding cylinder group can be turned off.

Growing community of inventors

Weil der Stadt, Germany

Patric Lardy