MOTOR VEHICLE COMPRISING A COMPUTER THAT INCLUDES A COMBINED TORQUE GRADIENT MAPPING OF INCREASE AND DECREMENT, METHOD AND PROGRAM BASED ON SUCH A VEHICLE

Abstract

The invention relates to a motor vehicle comprising: - a suspension system; - a means for filtering an overall torque setpoint (IVC), limiting a torque gradient of the overall torque setpoint (IVC); - a means for distributing the filtered overall torque setpoint across the suspension; and - a means for adapting suspension play; - a computer comprising a single incremental and decremental torque gradient (CID) map, enabling the calculation of an incremental torque gradient and a decremental torque gradient from the same map. The invention also relates to a method and a program based on such a vehicle. Figure 4

Description

Title of the invention: MOTOR VEHICLE COMPRISING A COMPUTER THAT INCLUDES A COMBINED GRADIENT MAPPING OF INCREMENT AND DECREMENT PAIR, METHOD AND PROGRAM BASED ON SUCH A VEHICLE

[0001] The invention relates to the field of torque control systems for motor vehicles comprising mechanical gearboxes.

[0002] These control systems include a preventive ride-by-wire filter function. This function filters a raw driver torque command in order to significantly reduce driveline oscillations when passing through mechanical clearances. It therefore provides a preventive corrective action on the oscillations generated by this passage through mechanical clearances. This significantly improves the vehicle's longitudinal ride-by-wire performance and also helps to define its longitudinal dynamics.

[0003] In the case of using the continuous preventive approval filter of patent application FR3133569A1 (illustrated in [Fig. 1] and 2), incremental torque gradient maps 12 and decremental torque gradient maps 13 are proposed, and are separate and then coordinated (step C) to feed the filter F. From a target torque value IVC, a filtered current torque CF is obtained. Tables 1 and 2 below illustrate extracts of incremental torque gradient maps 12 and decremental torque gradient maps 13 in the prior art.

[0004] Table 1: Example of increment torque gradient mapping from prior art (excerpt). IVC -20 -15 -10 -7 0 4 7 10 14 20 CF -15 0 0 30 30 30 30 30 30 30 30 -10 0 0 0 30 30 30 30 30 30 30 -7 0 0 0 0 30 30 30 30 30 30 0 0 0 0 0 0 30 30 30 30 30 4 0 0 0 0 0 0 4 4 4 4 7 0 0 0 0 0 0 0 4 4 4 10 0 0 0 0 0 0 0 0 50 50 14 0 0 0 0 0 0 0 0 0 50

[0005] Table 2: Example of prior art decrement torque gradient mapping (excerpt). IVC -20 -15 -10 -7 0 4 7 10 CF -20 0 0 0 0 0 0 0 0 -15 -10 0 0 0 0 0 0 0 -10 -10 -10 0 0 0 0 0 0 -7 -4 -4 -4 0 0 0 0 0 0 -4 -4 -4 -4 0 0 0 0 4 -4 -4 -4 -4 -4 0 0 0 7 -20 -20 -20 -20 -20 -20 0 0 10 -30 -30 -30 -30 -30 -30 -30 0

[0006] In the tables above, the target torque IVC (corresponding to the acceleration of the driver) and the filtered torque CF are expressed in tens of N.m1, the values ​​in the table are expressed in torque gradient (Nm / s).

[0007] Unfortunately, this function involves a large number of two-dimensional maps with many support points, which is very cumbersome in terms of memory space. Indeed, the continuous tuning filter is the most significant function in terms of ROM / RAM memory in the hybrid controller.

[0008] Furthermore, the inventor has noted that the increment and decrement maps used for the continuous approval filter are only half utilized. This implies that half of the ROM / RAM space per map is wasted.

[0009] An objective of the present invention is to remedy the defects of the prior art, and in particular to propose a solution for optimizing the memory occupied by the approval filters and the calculation times of the torque calculators.

[0010] To achieve this objective, the invention proposes a motor vehicle comprising a running gear system which includes: - a front wheel assembly including at least one drive unit, - a rear wheel assembly including at least one drive unit, the motor vehicle further comprising: - a means of filtering an overall torque setpoint to obtain a filtered overall torque setpoint, the filtering means limiting a torque gradient of the overall torque setpoint, characterized in that the motor vehicle includes a computer which includes at least one incremental and decremental torque gradient map, allowing the incremental torque gradient and the decremental torque gradient to be calculated from the same map, the calculation is performed using the overall torque setpoint and the filtered overall torque setpoint.

[0011] Advantageously, the invention allows for a significant gain in memory space in the computer, exceeding 50% (ROM and RAM memory gain). This reduces the computer's memory size. Furthermore, it lightens the load on the continuous approval filter function and makes it more readable.

[0012] Preferably, the increment and decrement couple gradient mapping is in the form of a symmetric square table.

[0013] This allows us to maintain the same behavior as separate maps.

[0014] Preferably, the diagonal of the increment and decrement torque gradient mapping, separating the increment side from the decrement side, is 0 Nm / s.

[0015] This ensures a clean separation between positive and negative couple gradients, and therefore a coherent and controlled linear interpolation.

[0016] Another object of the invention relates to a method for controlling a running gear system of a motor vehicle according to the invention, characterized in that it comprises the following steps: - a filtering step of an overall torque setpoint to obtain a filtered overall torque setpoint, in which a torque gradient of the overall torque setpoint is limited, - a calculation step in which the incremental torque gradient is calculated, and the decrement torque gradient from the same increment and decrement torque gradient mapping, the calculation is performed using the overall torque setpoint and the filtered overall torque setpoint.

[0017] Preferably, the control method includes a preliminary step of carrying out the increment and decrement torque gradient mapping, in the form of a symmetrical square table.

[0018] Preferably, the preliminary step of carrying out said mapping includes the creation of a diagonal separating the increment side from the decrement side, which is worth 0 Nm / s.

[0019] The invention further relates to a computer program comprising program code instructions for executing the steps of the control method according to the invention, when said program is running on a computer.

[0020] The invention will be further detailed by describing non-limiting embodiments, and based on the accompanying figures in which: - [Fig.l] schematically illustrates a motor vehicle suitable for implementing the invention; - [Fig.2] schematically illustrates a control system according to the prior art; - [Fig.3] schematically illustrates an implementation of separate increment and decrement maps of the control system according to the prior art; - [Fig.4] schematically illustrates an implementation of a combined increment and decrement mapping of the control system according to the invention.

[0021] The preventive ride control filter function consists of a global filtering module Ml that filters the overall IVC (Interpretation of Driver Will) torque setting corresponding to the driver's torque setting required to achieve the desired vehicle acceleration. The IVC torque filtering is performed continuously to provide longitudinal ride control. The filter in module Ml is centered around ONm, which allows for the management of the synchronization of the front wheel assembly 11 and the rear wheel assembly 17.

[0022] In [Fig.2], IVC is the global torque setpoint corresponding to the driver's acceleration intent, dCinc is the increment torque gradient, dCdec is the decrement torque gradient, CF is the filtered global torque setpoint, M14 is an integration module.

[0023] The Mil module limits the incremental torque gradient dCinc of the global torque setpoint IVC and the decremental torque gradient dCdec of the global torque setpoint IVC.

[0024] The prior art offered a separate increment card 12 and decrement card 13 as illustrated in [Fig.2].

[0025] The invention proposes to merge the increment and decrement maps in order to optimize the metrics and thus reduce the ROM and RAM memory used by the continuous approval filter.

[0026] The invention applies to all vehicles: electric, hybrid, 4x4, and conventional.

[0027] In order to optimize memory space on the computer, we identified unused areas in the increment 12 and decrement 13 maps. The inventor therefore merged these increment and decrement maps, resulting in a ROM and RAM memory saving of over 50%. This is highly advantageous because the continuous preventive approval filter function is the computer's most important function.

[0028] However, to do this it is preferable to ensure that the tables are square (for example dimension 23x23, ...) and therefore symmetrical to keep the same behavior than before. In addition, the diagonal separating the increment side from the decrement side should preferably be ONm / s to ensure a clean separation between positive and negative couple gradients, and therefore a consistent and controlled linear interpolation.

[0029] The implementation of the merged incremental and decremental torque gradient CID maps is illustrated in [Fig. 4]. Modules M1, M2, M3, and M4 are applied to the same map and then coordinated (step C) to feed filter F separately. From a target torque value IVC, a filtered current torque CF is obtained. Modules M1, M2, M3, and M4 are the four possible calibrations of the continuous preventive ride-by-wire filter. For example, mode M1 corresponds to the calibration of hybrid mode (internal combustion engine and electric motor), mode M2 ​​to the calibration of electric mode (electric motor only), mode M3 to the calibration of 4x4 mode, and mode M4 to the calibration of degraded mode (intervention of braking systems such as ESP, AEB, etc.). This allows the preventive ride-by-wire filter to be defiltered to apply corresponding requests, even if this degrades the vehicle's longitudinal ride-by-wire performance. One map per mode can be provided.

[0030] Table 3 below illustrates the result of this merging of the increment tables with the decrement tables.

[0031] Table 3: Example of combined CID increment and decrement mapping according to the invention (extract). IVC -20 -15 -10 -7 0 4 7 10 CF -20 0 30 30 30 30 30 30 30 -15 -10 0 30 30 30 30 30 30 -10 -10 -10 0 30 30 30 30 30 -7 -4 -4 -4 0 30 30 30 30 0 -4 -4 -4 -4 0 4 4 4 4 -4 -4 -4 -4 -4 0 4 4 7 -20 -20 -20 -20 -20 -20 0 50 10 -30 -30 -30 -30 -30 -30 -30 0

[0032] It is very clear that this time, the CID mapping is fully calibrated, so all the space is used.

[0033] In a mapping, it is now possible to have positive and negative torque gradients coexist, each with a specific role, one for support (or "tip in" in English, i.e., the foot placed on the accelerator pedal from 0% to 100% pressure) and the other for release (or "tip out" in English, i.e. the foot releasing the accelerator pedal from 100% to 0% pressure).

[0034] After non-regression tests between the continuous preventive approval filter function without and with the merged CID maps, the results are very satisfactory because they attest that there is no regression and that we have exactly the same behavior between "without" and "with" the merged tables.

[0035] The invention further relates to a method and a pre-check program implementing the elements discussed above. The program can be loaded into the memory of a motor vehicle controller or a specific computer.

Claims

Demands

1. Motor vehicle comprising a running gear system which includes: - a front wheel assembly (11) comprising at least one drive unit (12, 13), - a rear wheel assembly (17) comprising at least one drive unit (19), the motor vehicle further comprising: - a means for filtering an overall torque setpoint (IVC) to obtain a filtered overall torque setpoint (CF), the filtering means limiting a torque gradient of the overall torque setpoint (IVC), characterized in that the motor vehicle includes a computer which includes at least one increment and decrement torque gradient map (CID), allowing the calculation of the increment torque gradient (dCinc), and the decrement torque gradient (dCdec) from the same map, the calculation being carried out from the overall torque setpoint (IVC) and the filtered overall torque setpoint (CF).

2. Motor vehicle according to claim 1, characterized in that the increment and decrement torque gradient mapping (CID) is in the form of a symmetrical square table.

3. Motor vehicle according to any one of claims 1 to 2, characterized in that the diagonal of the increment and decrement torque gradient map (CID), separating the increment side from the decrement side, is 0 Nm / s.

4. A method for controlling a running gear system of a motor vehicle according to any one of claims 1 to 3, characterized in that it comprises the following steps: - a filtering step of an overall torque setpoint (IVC) to obtain a filtered overall torque setpoint (CF), in which a torque gradient of the overall torque setpoint (IVC) is limited, - a calculation step in which the incremental torque gradient (dCinc) and the decremental torque gradient (dCdec) are calculated from the same incremental and decremental torque gradient (CID) map, the calculation is performed from the global torque setpoint (IVC) and the filtered global torque setpoint (CF).

5. Control method according to claim 4, characterized in that it comprises a preliminary step of realizing the increment and decrement torque gradient mapping (CID), in the form of a symmetrical square table.

6. Control method according to claim 5, characterized in that the preliminary step of carrying out said mapping includes a realization of a diagonal separating the increment side from the decrement side, which is worth 0 Nm / s.

7. Computer program comprising program code instructions for performing the steps of the control process according to any one of claims 4 to 6, when said program is running on a computer.

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