阅读说明：本技术 使用动力转向系统的伺服电机根据速度探测周期产生测试周期 (Generating a test period based on a speed detection period using a servo motor of a power steering system ) 是由 马蒂厄·卢梭 克里斯多夫·拉维耶 于 2018-12-03 设计创作，主要内容包括：本发明涉及用于表征动力转向系统(1)的方法,用于经验地确定所述系统(1)的至少一个特性,所述动力转向系统包括至少一个转向盘(2)、设置有齿条(4)的转向机构(3)以及指示一个伺服电机(7)；在动力转向系统(1)被分配用于驱动车辆以使得所述车辆沿着根据所述车辆相对于其环境的情形确定的轨迹的转向阶段之外,所述方法包括：自动启动伺服电机(7)的步骤(a),在步骤(a)期间,计算机(13)用于自动地生成遵循称为预建立的探测周期(CY)的一个或多个周期的启动指令,并将其施加到伺服电机(7),而不需要对转向盘(2)的任何外部动作。(The invention relates to a method for characterizing a power steering system (1) for empirically determining at least one characteristic of said system (1), said power steering system comprising at least one steering wheel (2), a steering mechanism (3) provided with a rack (4) and an indication of a servomotor (7); outside a steering phase in which a power steering system (1) is assigned to drive a vehicle so that the vehicle follows a trajectory determined according to the situation of the vehicle with respect to its environment, the method comprises: step (a) of automatically activating the servo motor (7), during which step the computer (13) is used to automatically generate and apply to the servo motor (7) an activation command following one or more cycles called pre-established probing Cycles (CY), without requiring any external action on the steering wheel (2).)

1. A method for characterizing a power steering system (1) for empirically determining at least one characteristic, referred to as "desired characteristic", of the power steering system (1), the power steering system comprising: at least one heading defining device (2), such as a steering wheel (2), which allows to define an orientation of the power steering system called "steering angle" (a 1); a steering mechanism (3) provided with at least one movable member (4), such as a rack (4), the position (P4) of which is adapted to correspond to a selected steering angle (a 1); and at least one auxiliary electric machine (7) arranged to be able to drive the steering mechanism (3), the method comprising, in addition to a driving phase in which the power steering system (1) is dedicated to the driving of a vehicle so that the vehicle follows a path determined according to the situation of the vehicle with respect to its environment: a step (a) of automatically starting the auxiliary motor (7), during which a computer (13) is used to automatically generate and apply to the auxiliary motor (7) a starting setpoint following one or more pre-established periods called "probing periods" (CY), without requiring any external action on the heading defining device (2); a measurement step (b) according to which, during a probing cycle or upon completion of said probing Cycle (CY), at least one physical parameter (P7_ mes, T7_ mes, P4_ mes, T2_ mes, V2_ mes), called "index parameter", is measured, said physical parameter being specific to the response provided by the power steering system to the automatic starting of the auxiliary electric machine (7) and being representative of a desired characteristic; then there is an analysis step (c) during which the desired characteristic is quantified according to the measurement of the index parameter, said method being characterized in that during the automatic starting step (a) a speed detection cycle (CY _ speed) or a succession of speed detection cycles (CY _ speed) is applied, wherein each speed detection cycle (CY _ speed) servo-controls the speed (V7, V4, V2) of the auxiliary motor (7) and/or of the selected movable member (4, 2) of the steering mechanism (3).

2. Method according to claim 1, characterized in that it is used for identifying at least one position of a first end-of-stroke stop (S1) of a steering mechanism (3), and/or one position of a second end-of-stroke stop (S2) of the steering mechanism opposite to the first end-of-stroke stop (S1), and/or a maximum stroke (L4) of a movable member (4) corresponding to the distance between the first end-of-stroke stop (S1) and the second end-of-stroke stop (S2), and/or a central position (C0) of the movable member (4) located midway between the two end-of-stroke stops (S1, S2), and in that, for this purpose, during the automatic starting step (a), a speed detection cycle (CY _ speed) applies a non-zero speed setpoint (V7, V7) in a first direction, V4, V2) until the steering mechanism (3) is stopped by the first end-of-stroke stop (S1), and/or applying a non-zero velocity set point (V7, V4, V2) in the second direction, respectively, until the steering mechanism (3) is stopped by the second end-of-stroke stop (S2).

3. A method according to any one of the foregoing claims, characterised in that the method is used for identifying the acoustic properties of the power steering system (1) and in that for this purpose, while applying a speed detection cycle (CY _ speed), a noise indicator parameter is measured during the measuring step (b) that represents the sound level of the auxiliary motor (7) and/or the steering mechanism (3).

4. A method according to any one of the preceding claims, characterized in that the method is used for identifying the dynamic behaviour of a power steering system among: the presence of one or more possible stuck points, or the value of the internal friction of the steering mechanism that affects the displacement of the movable member; and is characterized in that for this purpose, during the measuring step (b), while applying the speed detection cycle (CY _ speed), a force index parameter (T7_ mes) representing the force provided by the auxiliary motor (7) is measured, and during the analyzing step (c), a stuck point is identified when the force index (T7_ mes) is detected to reach or exceed a predetermined warning threshold, and correspondingly, upon a reverse steering, the friction force is evaluated as a function of the drop in the force index (T7_ mes).

5. Method according to any of the preceding claims, characterized in that a heading definition device comprises a steering wheel (2), the rotation of which steering wheel (2) is related to the displacement of a steering mechanism (3), and that the steering wheel (2) is provided with an index marking a unique reference position (I0, I1, I2) of the steering wheel in one complete rotation, the method being used for identifying one or more positions (I0, I1, I2) of the travel of the steering wheel by means of the index in a reference coordinate system associated with an auxiliary motor (7), characterized in that, for this purpose, a speed detection period (CY _ speed) is defined as a stationary period (32, 132) forming the rotational speed of the steering wheel, which stationary period (32, 132) extends from a stationary period start position (X1) to a stationary period end position (X2), and in accordance with the stationary period (32, b) is defined, 132) Between a stationary phase start position (X1) and a stationary phase end position (X2), the servo-controlled rotational speed (V2) of the steering wheel is kept constant and automatically in the vicinity of a stationary phase nominal value (Vpeak _1, Vpeak _2) and has an error of less than 20%, preferably less than 10%, or less than or equal to 5% of said stationary phase nominal value (Vpeak _1, Vpeak _2), and is characterized in that the stationary phase start position (X1) and the stationary phase end position (X2) are selected such that the stationary phase (32, 132) covers a sufficiently large position range to perform at least one stroke, and preferably at least two strokes, indexed in the same displacement direction.

6. Method according to any of the preceding claims, characterized in that it allows determining at least one, and preferably a plurality of, desired characteristics of:

-a friction value specific to the steering system (1) which is resistant to a displacement of a movable member (4) of the steering system, for example a displacement of a rack (4),

-measurement of the stroke (L4) of the steering rack (4),

-an indication of the position of an end-of-stroke stop (S1, S2) of the steering mechanism (3),

-identification of a central position (C0) of the steering mechanism (3) equidistant from the end-of-stroke stops (S1, S2),

-identification of one or more index positions (I0, I1, I2), said index positions (I0, I1, I2) being indicated by indices marking a unique reference position of the steering wheel (2) in the same full rotation,

-the sound level generated by the auxiliary motor (7) and/or the steering mechanism (3),

-an identification of a position, called "stuck point", in which the steering mechanism (3) has a resistance to displacement, and in particular a viscous resistance, above a predetermined threshold.

7. A power steering system (1), the steering system (1) being for equipping a vehicle and comprising: at least one heading defining device (2), such as a steering wheel, which enables the driver to define a steering angle (A1) of the power steering system; a steering mechanism (3) provided with at least one movable member (4), such as a rack, the position (P4) of which is adapted to correspond to a selected steering angle; and at least one auxiliary motor (7), the auxiliary motor (7) being arranged to be able to drive the steering mechanism (3); on the one hand, the power steering system (1) comprises a first on-board module (8), called "auxiliary module", which contains a first set of functions, called "auxiliary rules", which allow, when the power steering system is dedicated to the driving of the vehicle, to generate driving setpoints towards the auxiliary electric machine so that the vehicle follows a path determined according to the situation of the vehicle with respect to its environment, and on the other hand, the power steering system (1) comprises a second on-board module (13), called "characterization module", which contains a second set of functions, called "characterization functions", which are different from the auxiliary rules, and which allows, during periods in which the power steering system is not dedicated to the driving of the vehicle, to automatically implement a characterization method aimed at empirically determining at least one characteristic, called "desired characteristic", of the power steering system; the characterization method comprises the following steps: a step (a) of automatically starting the auxiliary electric machine (7), during which step the second on-board module (13) automatically generates and applies to the auxiliary electric machine (7) starting set points (T7, V7, P7) following one or more pre-established periods, called "probing periods" (CY), without requiring any external action on the heading defining device (2), in order to carry out a measuring step (b), according to which, during a probing period or upon completion of said probing period, at least one physical parameter (P7_ mes, T7_ mes, P4_ mes, T2_ mes, V2_ mes), called "index parameter", is measured, specific to the response provided by the power steering system (1) to the automatic starting of the auxiliary electric machine (7), and representative of the desired characteristic; then there is an analysis step (c) during which the desired characteristic is quantified on the basis of the measurement of the index parameter, characterized in that during the automatic starting step (a) a speed detection cycle (CY _ speed) or a plurality of consecutive speed detection cycles (CY _ speed) is applied, wherein each speed detection cycle (CY _ speed) servo-controls the speed (V7, V4, V2) of the auxiliary motor (7) and/or of the selected movable member (4, 2) of the steering mechanism (3).

8. The power steering system according to claim 7, characterized in that the second on-board module (13) comprises at least two of the following characterizing functions:

-a function characterizing the position of an end-of-stroke stop (S1) using a speed detection cycle (CY _ speed) during which a non-zero speed setpoint (V7) is applied to the auxiliary motor (7) in a first direction to drive the auxiliary motor and steering until the steering (3) abuts on a first end-of-stroke stop (S1);

-a function characterizing the sound level using a speed detection period (CY _ speed) of a speed plateau (32, 132) providing a speed of servo control that is substantially constant;

-identifying a function of index positions (I0, I1, I2) using a speed detection cycle (CY _ speed) adapted to servo-controlling the rotation speed of the steering wheel (2) by means of the auxiliary motor (7) according to a substantially constant speed plateau (32, 132) and over a stroke large enough to ensure passing through at least one index position or at least two index positions in the same displacement direction, each index position being associated with a complete rotation of the steering wheel.