Method of setting the transmission ratio of a continuously variable gear

• US 6,173,227 B1
• Filed: 06/24/1998
• Issued: 01/09/2001
• Est. Priority Date: 01/12/1996
• Status: Expired due to Term

• Current Assignee: ZF Friedrichshafen AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: ZF Friedrichshafen AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Gillich, Udo, Vorndran, Ralf, Speicher, Patrick, Danz, Wolfgang
• Primary Examiner(s): LOUIS JACQUES, JACQUES H
• Application Number:
  US09/091,909
• Time in Patent Office: 930 Days
• Field of Search: 701/51, 701/55, 701/56, 701/58, 701/60, 701/61, 701/62, 701/64, 701/57, 474/18, 474/29, 474/28, 477/48, 477/45, 477/138, 477/47, 477/37, 477/43, 477/46, 477/49, 477/69, 477/115, 74/385, 74/336 R
• US Class Current: 701/51
• CPC Class Codes: B60W 2050/0057 Frequency analysis, spectral techniques or transforms
• CPC Class Codes: F16H 2061/0015 Transmission control for optimising fuel consumptions
• CPC Class Codes: F16H 2061/0081 Fuzzy logic
• CPC Class Codes: F16H 59/18 dependent on the position of the accelerator pedal
• CPC Class Codes: F16H 59/36 Inputs being a function of speed
• CPC Class Codes: F16H 59/44 dependent on machine speed of the machine, e.g. the vehicle
• CPC Class Codes: F16H 59/48 Inputs being a function of acceleration
• CPC Class Codes: F16H 59/54 dependent on signals from the brakes, e.g. parking brakes
• CPC Class Codes: F16H 59/72 dependent on oil characteristics, e.g. temperature, viscosity
• CPC Class Codes: F16H 61/66254 controlling of shifting being influenced by a signal derived from the engine and the main coupling
• CPC Class Codes: F16H 61/6648 controlling of shifting being influenced by a signal derived from the engine and the main coupling

Abstract

The invention relates to a method of adjusting the transmission ratio of a continuously variable gear. The position of a current operating point (B_akt) in a predetermined driving range is constantly adjusted in accordance with the driving situation. The position of the operating point is also determined by range boundaries (UG, OG) which can be varied in accordance with the driving resistance and the driver'"'"'s manner of driving. The method is characterized in that it simplifies development and application.

Claims

1. A method of setting the transmission ratio of a continuously variable gear having a means (1, 9) for detecting at least one input signal which is derived from a driver-vehicle system and for processing at least one output signal which can communicate a change, within the scope of an operating strategy, of at least one of a setting of a reduction ratio, a setting of a speed of a prime mover and a setting of a vehicle acceleration, said method comprising the step of:

constantly redetermining an operating point setting (B_akt) for said gear in a preset driving range having a lower boundary (UG) and an upper boundary (OG) by said means processing actual, substantially driver-dependent input signals without filtering;

converting the at least one input signal (u) to a logical output signal (uB), and said input signal is at least one of a driving resistance and a driver'"'"'s mode of driving and said logical output signal is linked to an influencing factor which varies the range boundaries (UG, OG);

generating a dynamic driving range, essentially based upon said signal input of a current driving situation, by said means varying said lower, and upper boundaries (UG, OG) of the preset driving range.

2. The method according to claim 1, further comprising the step of orientating the operating point setting (B_akt) in the dynamic driving range.

3. The method according to claim 1, further comprising the step of changing the influencing factor (BF) by manual contact of a driver.

4. The method according to claim 3, further comprising the step of changing the influencing factor (BF) by a temperature of the vehicle.

5. A method of setting the transmission ratio of a continuously variable gear having means (1, 9) for detecting at least one input signal which is derived from a driver-vehicle system and for processing at least one output signal which can communicate a change, within the scope of an operating strategy, of at least one of a setting of a reduction ratio, a setting of a speed of a prime mover and a setting of a vehicle acceleration, said method comprising the steps of:

constantly redetermining an operating point setting (B_akt) for said hear in a preset driving range having a lower boundary (UG) and an upper boundary (OG) by said means processing actual, substantially driver-dependent input signals without filtering; and

converting the at least one input signal (u) to at least one logical output signal (uA), calculating from said logical output signal a displacement (delta_x) of the operating point setting subsequently integrating said displacement into a parameter (x) and calculating by interpolation, taking into account the range boundaries (UG, OG), an adjustment parameter (y) used to communicate said change.

6. The method according to claim 5, further comprising the step of, by said means, processing several logical output signals (uA) into part interpolation factors (Δ

_i_fak), combining said part interpolation factors to form an interpolation factor (i_fak) and interpolating, taking into account the range boundaries (UG, OG), an output signal (iV_nom).

7. The method according to claim 6, further comprising the step of, by said means, comparing the output signal (iV_nom) with boundary gradients for an upshift and a downshift (HS, RS).

8. The method according to claim 6, further comprising the step of converting the logical output signals (uA) to part interpolation factors (Δ

_i_fak) by control equipment.

9. The method according to claim 5, further comprising the step of, by the adjustment parameter, setting at least one of the transmission ratio, an engine speed (n_Mot), and a speed of the primary disc (n_S1) of the continuously variable gear.

10. The method according to claim 5, further comprising the step of feeding the parameter (x) back for calculating the displacement.

11. A method of setting the transmission ratio of a continuously variable gear having means (1, 9) for detecting at least one input signal which is derived from a driver-vehicle system and for processing at least one output signal which can communicate a change, within the scope of an operating strategy, of at least one of a setting of a reduction ratio, a setting of a speed of a prime mover and a setting of a vehicle acceleration, said method comprising the steps of:

constantly redetermining an operating point setting (B_akt) for said gear in a preset driving range having a lower boundary (UG) and an upper boundary (OG) by said means processing actual, substantially driver-dependent input signals without filtering; and

converting the at least one input signal (u) to at least one logical output signal (uA), calculating from said logical output signal a displacement (delta_y) of the operating point integrating said displacement into an operation point setting (y′

), and interpolating from said operation point setting, taking into account the range boundaries (UG, OG), a correcting variable (y).

12. The method according to claim 11, further comprising the step of setting the acceleration (a) by the output signal.

13. The method according to claim 11, further comprising the step of converting the logical output signals (uA) by fuzzy-logic control equipment to displacement of the operating point setting (delta_y).

14. The method according to claim 11, further comprising the step of feeding the position of the correcting variable (y) between the range boundaries (UG, OG) back for calculating the displacement.

15. A method of setting the transmission ratio of a continuously variable gear having means (1, 9) for detecting at least one input signal which is derived from a driver-vehicle system and for processing at least one output signal which can communicate a change, within the scope of an operating strategy, of at least one of a setting of a reduction ratio, a setting of a speed of a prime mover and a setting of a vehicle acceleration, said method comprising the steps of:

constantly redetermining an operating point setting (B_akt) for said continuously variable gear in a preset driving range having a lower boundary (UG) and an upper boundary (OG) by said means processing actual, substantially driver-dependent input signals without filtering;

generating a dynamic driving range, essentially based upon said signal input of a current driving situation, by said means varying said lower and upper boundaries (UG, OG) of the preset driving range;

orientating the operating point setting (B_akt) in the dynamic driving range; and

converting, by said means, the at least one input signal (u) to at least one logical output signal (uA), calculating from said logical output signal a displacement (delta_x) of the operating point setting, subsequently integrating said displacement into a parameter (x) and calculating by interpolation, taking into account the range boundaries (UG, OG), an adjustment parameter (y) used to communicate said change.