Method for controlling an operating characteristic of a vehicle, such as the ground clearance
The invention relates to a method for controlling an operating characteristic (for example ground clearance or acceleration) of a vehicle ( 100 ) resting on a contact surface ( 200 ) by means of at least one landing gear ( 150 ) comprising means of actuating ( 160 ) adapted to vary a behaviour of the landing gear when the latter is in contact with the contact surface, whereby the said method makes the operating characteristic of the vehicle dependent upon a given set-point by generating a command intended for the means of actuating as a function of a difference (ε) between the operating characteristic and the set-point. According to the invention, the control system comprises the use of an estimation (P est ) of a load (P) seen by the landing gear to generate a modification of the command so as to minimise a variation in the deviation caused by a variation in the load.
1 . A method for controlling an operating characteristic of a vehicle resting on a contact surface by at least one landing gear comprising means of actuating adapted to vary a behavior of the landing gear when the latter is in contact with the contact surface, wherein the method makes the operating characteristic of the vehicle dependent upon a given set-point and an estimation of a load seen by the landing gear by generating a command intended for the means of actuating as a function of a difference between the operating characteristic and the set-point and by modifying the command as a function of a variation of the estimation of the load so as to minimize a variation in the deviation caused by a variation in the load.
2 . The method for controlling the landing gear according to claim 1 , wherein the command is modified by adding to it a corrective command determined as a function of the estimation of the load seen by the landing gear.
3 . The method according to claim 2 , wherein the corrective control is determined by a predictive algorithm implementing a model of the behavior of the landing gear and anticipating the reaction of the landing gear to a variation in the load seen by the landing gear.
4 . The method according to claim 1 , wherein the command is determined by a controller having characteristics dependent upon the estimation of the load seen by the landing gear.
5 . The method according to claim 4 , wherein the controller is of the PID type characterized by gains which are determined as a function of the estimation of the load seen by the landing gear.
6 . The method according to claim 5 , wherein the gains are determined by means of a parametric function of the estimation of the load, or a table of values.
7 . The method according to claim 1 , wherein the controlled operating characteristic is a ground clearance of the vehicle.
8 . The method according to claim 1 , wherein the command is intended for an electric motor of the landing gear adapted to vary a load/sinkage characteristic of the landing gear capable of modifying the behavior of the landing gear.
9 . The method according to claim 8 , applied to a vehicle whose landing gear comprises a shock-absorber cylinder whose motor enables a no-load length to be varied.
10 . A magnetically levitated vehicle comprising a landing gear associated with means of actuating arranged to implement a control system according to claim 1 .
11 . The method according to claim 1 , wherein the operating characteristic comprises a ground clearance or an acceleration of the vehicle.
12 . A method for controlling an operating characteristic of a vehicle resting on a contact surface by at least one landing gear comprising means of actuating adapted to vary a behavior of the landing gear when the latter is in contact with the contact surface, wherein the method makes the operating characteristic of the vehicle dependent upon a given set-point and an estimation of a load seen by the landing gear by generating a command intended for the means of actuating as a function of a difference between the operating characteristic and the set-point and by modifying the command as a function of a rate of variation of the estimation of the load so as to minimize a variation in the deviation caused by a variation in the load.