Assessment device and method for estimating the vehicle mass of a vehicle

Abstract

The invention relates to an evaluation device and to a method for estimating a vehicle mass (m) of a vehicle by determining at least one torque value of a non-zero acceleration or deceleration torque applied to the vehicle by means of at least one brake and / or acceleration device of the vehicle and a respective one simultaneous determined measured value (a) of a resulting change (a) in the speed of the vehicle over a time interval and estimating the vehicle mass (m) taking into account the at least one torque value and the respective one measured value (a), wherein the at least one torque value and the respective one measured value (a) are determined over a time interval in which the non-zero acceleration or deceleration torque acts on the vehicle at least partially by means of at least one electric motor of the vehicle as at least one part of the at least one brake and / or acceleration device by driving the vehicle by means of the at least one electric motor or by braking the vehicle by means of the at least one electric motor operating in its recuperation mode.

Description

Technical Field

[0001] This invention relates to an evaluation device for a vehicle and a control device for at least one electric motor of at least one vehicle that can operate in its regeneration mode. Similarly, this invention relates to a method for estimating the vehicle mass. Furthermore, this invention relates to a method for braking a vehicle by means of at least one electric motor operating in its regeneration mode. Background Technology

[0002] DE 102 35 563 A1 describes a method and apparatus for determining the vehicle mass. To determine the vehicle mass, the vehicle's acceleration value and simultaneous driving value are detected at at least one time point and evaluated together, taking into account changes in the lane gradient in which the vehicle is traveling at that respective time point. Summary of the Invention

[0003] The present invention provides an evaluation device for a vehicle having the features of claim 1, a control device for at least one electric motor of at least one vehicle that can operate in its regeneration mode having the features of claim 6, a method for estimating the vehicle mass having the features of claim 7, and a method for braking a vehicle by means of at least one electric motor operating in its regeneration mode having the features of claim 9.

[0004] Advantages of the invention This invention provides an advantageous possibility for reliably estimating the vehicle mass of a vehicle without knowing the lane gradient / road gradient or the tilting moment occurring in the lane in which the vehicle is traveling. Since lane gradient / road gradient or tilting moment is often difficult and frequently only inaccurate (online) to determine using conventional methods, and since prior art models for determining vehicle mass considering lane gradient / road gradient or tilting moment or the resulting frictional effects often have dynamic inconsistencies, the vehicle mass of the corresponding vehicle can be estimated more reliably using this invention. With prior art, vehicle mass can typically be determined with only ±10% accuracy, while with this invention, the estimation tolerance is at most 5%. Therefore, this invention not only makes vehicle mass estimation easier but also enables estimations that are more reliable and accurate than those of the prior art.

[0005] Another advantage of this invention is that it can be implemented using a relatively simple and feasible design / programming method for estimating vehicle mass, requiring only minimal effort. Therefore, the invention is also relatively low-cost.

[0006] In one advantageous embodiment of the evaluation device, the electronic device is additionally designed and / or programmed such that the vehicle mass can be estimated by means of the electronic device using an estimation algorithm that repeats differential equations comprising at least the torque value and the measured value at a predetermined frequency during time intervals. As will become clear from the following description, when using such an estimation algorithm, the frictional effects on the corresponding vehicle are (automatically) eliminated. This facilitates the estimation performed by means of the evaluation device and contributes to a more accurate estimation of the vehicle mass.

[0007] Preferably, the electronic device is additionally designed and / or programmed to enable the determination of the time interval such that, during the time interval, at least 50% of the non-zero acceleration or deceleration torque applied to the vehicle by means of at least one braking and / or acceleration device is applied to the vehicle by means of at least one electric motor. The embodiment of the evaluation device described herein thus utilizes the advantage that at least one electric motor is typically manipulated / controlled such that the resulting motor acceleration or deceleration torque is (substantially) independent of the lane gradient / road gradient in which the vehicle is currently traveling. Therefore, the embodiment of the evaluation device described herein enables accurate estimation of vehicle mass without knowledge of the lane gradient / road gradient or tilt torque.

[0008] In a particularly advantageous embodiment of the evaluation device, the electronics are additionally designed and / or programmed to specify the time interval such that, during this time interval, at least 90% of the non-zero acceleration or deceleration torque applied to the vehicle by means of the at least one braking and / or accelerating device acts on the vehicle by means of the at least one electric motor. Therefore, the vehicle mass is estimated only during vehicle acceleration or deceleration primarily caused by the at least one electric motor of the vehicle. In this way, an estimation tolerance of less than 5% can be reliably achieved.

[0009] For example, the electronic device may additionally be designed and / or programmed such that, by means of the electronic device, the time interval can be defined such that, during the time interval, the deceleration torque of the negative motor acts on the vehicle at least in part by means of at least one motor operating in its regenerative mode. The at least one motor used in its regenerative mode precisely for regenerative braking of the vehicle can be easily and reliably controlled such that the resulting deceleration is (substantially) independent of lane / road gradient or tilt torque.

[0010] It is also advantageous to have a control device for at least one electric motor of at least one vehicle that can operate in its regeneration mode, the control device having such an evaluation device and control electronics, by means of which at least one motor control signal can be output to the at least one electric motor taking into account the vehicle mass estimated by means of the evaluation device, so that the vehicle can be braked by means of at least one electric motor operating in its regeneration mode. As explained in more detail below, the at least one electric motor can be better controlled by using the precisely determined vehicle mass.

[0011] The aforementioned advantages are also maintained when implementing the corresponding method for estimating the vehicle's mass. It is specifically noted that the method for estimating vehicle mass can be improved according to the embodiments of the evaluation device explained above.

[0012] Furthermore, the method for braking the vehicle by means of at least one electric motor operating in its regeneration mode also offers significant advantages. The method for braking the vehicle by means of at least one electric motor operating in its regeneration mode can also be improved based on the embodiments explained above for the evaluation device or control equipment. Attached Figure Description

[0013] Other features and advantages of the invention are explained below with reference to the figures. Wherein: Figure 1 A schematic diagram illustrating one embodiment of the evaluation apparatus; Figure 2 A flowchart illustrating one implementation of a method for estimating the vehicle mass is shown; and Figure 3 A flowchart is shown to illustrate one embodiment of a method for braking a vehicle by means of at least one electric motor operating in its regeneration mode. Detailed Implementation

[0014] Figure 1 A schematic diagram showing one embodiment of the evaluation apparatus is provided.

[0015] The vehicle mass m can be estimated using the evaluation device 10 described below. It should be noted that the availability of the evaluation device 10 is not limited to a specific vehicle type / motor vehicle type for which the estimation device is used. Optionally, the evaluation device 10 can be installed at the vehicle / motor vehicle using the evaluation device. Alternatively, the vehicle mass m can be estimated / be estimated by means of the evaluation device 10, which exists separately from the vehicle / motor vehicle, for example, by the evaluation device 10 communicating with the vehicle / motor vehicle's data and / or value output device via at least one wireless communication interface.

[0016] The evaluation device 10 has electronic devices 12a and 12b, by means of which the vehicle mass m can be estimated. The design and / or programming of the electronic devices 12a and 12b ensures that: by means of the electronic devices 12a and 12b, the acceleration and / or deceleration torque M applied to the vehicle (actively) by means of at least one braking and / or accelerating device of the vehicle within a time interval is considered. activ At least one torque value M activ The vehicle mass m can be estimated / estimated given a simultaneously determined measurement value a of the change a caused by the vehicle's speed v. This can also be defined as follows: the vehicle mass m is determined by means of electronic devices 12a and 12b, taking into account at least one pair of values, where each pair of values ​​includes an acceleration and / or deceleration torque M applied to the vehicle by means of at least one braking and / or accelerating device within a time interval. activ A torque value M activ And a simultaneously determined measurement a of the change a caused by the speed v of each traveling vehicle.

[0017] The change in the speed v of a moving vehicle, a, can also be referred to as the positive or negative acceleration a of the moving vehicle. The change in the speed v of a moving vehicle, a, can be determined by means of at least one sensor of the vehicle (not shown), such as at least one longitudinal acceleration sensor of the vehicle. Since longitudinal acceleration sensors have traditionally been installed in a large number of vehicle types for other uses, such as airbags, additional sensor technology is usually not required to determine the change in the speed v of a moving vehicle.

[0018] With the aid of the design and / or programming of electronic devices 12a and 12b, an acceleration or deceleration torque M is caused to be applied to the vehicle by means of at least one braking and / or acceleration device during the (entire) time interval used to estimate the vehicle mass m. activ The torque M is not equal to zero. Therefore, during the time interval used to estimate the vehicle mass m, the vehicle is driven by a positive acceleration torque or braked by a negative deceleration torque, wherein at least one value is present during the time interval. Additionally, electronic devices 12a and 12b are designed and / or programmed such that a time interval can be specified by means of electronic devices 12a and 12b, during which a non-zero (actively) acceleration or deceleration torque M is applied to the vehicle. activ At least one (not shown) electric motor of the vehicle acts on the vehicle, at least partially by means of at least one part of the vehicle's braking and / or acceleration device. Therefore, the acceleration or deceleration torque M activThis is caused, at least in part, by driving the vehicle with the aid of at least one electric motor (used as a drive motor) or by braking the vehicle with the aid of at least one electric motor operating in its regeneration mode. However, it should be noted that the acceleration or deceleration torque M applied to the vehicle by means of at least one braking and / or accelerating device... activ It should not be understood as (merely) the acceleration torque or deceleration torque M of an electric motor acting on the vehicle by means of at least one electric motor. m As at least one braking and / or acceleration device, in addition to at least one electric motor, other components of the vehicle, such as the vehicle's internal combustion engine or the vehicle's hydraulic braking system, may also be used.

[0019] The evaluation device 10 / its electronic devices 12a and 12b define a time interval such that during the time interval, an acceleration or deceleration torque M is (actively) applied to the vehicle. activ The evaluation device 10 utilizes (commonly used) control techniques of at least one electric motor, acting on / being acted upon by at least one electric motor in the vehicle. Typically, when at least one electric motor is used (in conjunction) for accelerating or decelerating the vehicle, the at least one electric motor is controlled such that an acceleration or deceleration torque M acts on the moving vehicle at least partially by means of the at least one electric motor. activ (Essentially) it is independent of the lane gradient / road gradient or the corresponding tilt moment of the lane in which the vehicle is currently traveling. Therefore, the estimation of the vehicle mass m performed by means of the evaluation device 10 is done without considering the lane gradient / road gradient or the tilt moment. Since the lane gradient / road gradient and tilt moment can only be determined relatively inaccurately using conventional methods, the estimation of the vehicle mass m performed by means of the evaluation device 10 / its electronics 12a and 12b can be performed not only more easily and quickly, but also more accurately.

[0020] Optionally, the evaluation device 10 / its electronics 12a and 12b can be designed and / or programmed such that the vehicle mass m is estimated by means of the evaluation device 10 / its electronics 12a and 12b only when specific activation conditions are present. For example, Figure 1The evaluation device 10 has a first calculation block 12a as part of its electronic devices 12a and 12b, which only outputs an activation signal 14 to a second calculation block 12b, which is another part of the electronic devices 12a and 12b, when a pre-given activation condition is met. Accordingly, the second calculation block 12b performs the estimation of the vehicle mass m only when it receives the activation signal 14 from the first calculation block 12a. The pre-given activation condition is at least: an acceleration or deceleration torque M is (actively) applied to the vehicle by means of at least one braking and / or acceleration device during the (entire) time interval in which at least one value pair is located. activ It is not only not equal to zero, but is also caused / caused at least in part by means of at least one electric motor.

[0021] The electronic device / its second calculation block 12b, for example, can use model equations to estimate the vehicle mass m, said model equations being based on equation (Equation 1): (Equation 1) Where r is the rolling radius, and M total It is the total acceleration or deceleration torque applied to the vehicle, in addition to the acceleration or deceleration torque M applied to the vehicle (actively) by means of at least one braking and / or accelerating device. activ In addition, rolling friction and tilting moment are also included. Due to favorable starting conditions, to estimate the vehicle mass m, equation (Equation 2) can be used as the model equation: (Equation 2) Where X is the offset, and rolling friction is included in the offset. Therefore, rolling friction can be estimated together with the offset X. This is because at least one electric motor is used to (together) generate (actively) applied acceleration or deceleration torque M to the vehicle. activ Therefore, the offset X is (almost) constant in time. (Since the change in velocity v, measured by means of at least one longitudinal acceleration sensor, is also used as an input for estimation, the tilting moment is already included in this (dieser).) Thus, a favorable possibility is provided for estimating the vehicle mass m by means of equation (Equation 2).

[0022] Preferably, the electronic devices 12a and 12b / their second computing block 12b are designed and / or programmed to estimate the vehicle mass m (and possible offset X) of the vehicle using an estimation algorithm that repeats at a predetermined frequency during time intervals, including at least the torque value M. activ And the differential equation for the simultaneously determined measured value 'a'. Therefore, by adapting the parameters of the estimation method to the torque value M... activThe vehicle mass m is estimated along with the simultaneously determined measurement value a (as a parameter estimate) (and possibly the offset X). This can also be limited to a matching (Abgleichen) of the vehicle mass m (and possibly the offset X).

[0023] For example, to estimate the vehicle mass m (and possibly the offset X), the RLS algorithm (Recursive-Least-Squares-Algorithm) can be used. This algorithm allows the estimated parameters to be continuously adapted to the torque value M. activ The measured value 'a' is determined simultaneously to ensure an accurate estimate of the vehicle mass 'm' (and possible offset 'X'). However, alternatively, other online estimation algorithms, such as the LMS algorithm (Least-Mean-Squares-Algorithm), can also be used. When using the LMS algorithm, equations / differential equations (Equations 3 through 5) can be repeated at each time step, for example, at a pre-given frequency: (Equation 3) (Equation 4) (Equation 5) , Where K m and K f These are adjustment parameters for the estimated speed.

[0024] However, the activation conditions can still be further restricted / specified, as desired. For example, a time interval can be specified by means of electronic devices 12a and 12b, such that during this time interval, an acceleration or deceleration torque M is (actively) applied to the vehicle by means of at least one braking and / or accelerating device. activ At least 30%, such as particularly at least 50%, preferably at least 70%, specifically at least 90%, is applied to the vehicle by means of at least one electric motor. Alternatively or supplementarily, time intervals can be specified by means of electronic devices 12a and 12b, such that during these time intervals, the negative motor deceleration torque M... m The vehicle is activated by at least one electric motor operating in its regeneration mode. Another activation condition could be: the negative motor deceleration torque M acting on the vehicle by at least one electric motor operating in its regeneration mode. m The value is greater than or equal to the acceleration or deceleration torque M applied to the vehicle (actively) by means of at least one braking and / or acceleration device. activ 30% of the value. For example, the reduction torque M of a negative motor. mThe value can be greater than or equal to the acceleration or deceleration torque M applied to the vehicle by means of at least one braking and / or acceleration device. activ The value is 50%, selectively greater than or equal to 70%, and specifically greater than or equal to 90%.

[0025] Another starting condition could be that the vehicle's speed v is within a pre-defined normal range. In this way, the effect of friction can be further minimized, and the estimation tolerance can be improved accordingly.

[0026] exist Figure 1 In the implementation of this method, the starting conditions are exemplarily additionally specified / limited by means of the design and / or programming of electronic devices 12a and 12b / first calculation block 12a, such that during the time interval, a non-zero acceleration or deceleration torque M is applied to the vehicle (actively) by means of at least one braking and / or acceleration device. activ At least 98% of the power to the vehicle is achieved through at least one electric motor. ,Right now To this end, the first calculation block 12a evaluates the vehicle's speed v, at least one pressure p measured in the vehicle's hydraulic braking system, and the negative electric motor deceleration torque M applied to the vehicle by means of at least one electric motor operating in its regeneration mode. m If the first calculation block 12a identifies, in the presence of at least one pressure p close to atmospheric pressure, that the velocity v decreases with time and is subjected to a negative motor deceleration torque M by means of the motor operating in its recovery mode. m If the value is high enough, the first calculation block 12a will output the activation signal 14 to the second calculation block 12b.

[0027] Then, the second calculation block 12b can use equation (Equation 6) as the model equation to estimate the vehicle mass m, where: (Equation 6) Alternatively, equations / differential equations (Equation 3) to (Equation 5) can also be used by the second computational block 12b (where... ).

[0028] The evaluation device 10 described above can be selectively incorporated into a control device 16 for at least one electric motor of at least one vehicle that can operate in its regeneration mode. In addition to the evaluation device 10, a (not shown) control electronics 18 can also be integrated into the control device 16, by means of which at least one electric motor control signal 20 can be output / output to at least one electric motor, taking into account the vehicle mass m estimated by means of the evaluation device 10, so that the vehicle can be braked / braked by means of at least one electric motor operating in its regeneration mode. The advantages of equipping the control device 16 with the evaluation device 10 will become clear from the description below.

[0029] Figure 2 A flowchart illustrating one implementation of a method for estimating the vehicle mass is shown.

[0030] The vehicle / motor used to perform the methods described herein may be, for example, a PKW (passenger vehicle). However, it should be noted that the feasibility of the methods described herein is not limited to a specific vehicle / motor type.

[0031] In method step S1, at least one torque value of a non-zero acceleration or deceleration torque applied to the vehicle by means of at least one braking and / or acceleration device during a time interval, and one simultaneously measured value of the change in speed of the traveling vehicle, are determined. Refer to the description above for a sensor suitable for measuring each of these measurements.

[0032] Furthermore, at least one torque value and one measurement value are determined within a time interval, during which a non-zero acceleration or deceleration torque is applied to the vehicle at least partially by means of at least one electric motor of the vehicle, which is at least part of at least one braking and / or acceleration device. As explained above, therefore, during this time interval, the non-zero acceleration or deceleration torque is applied at least partially by means of at least one electric motor (used as a drive motor) to drive the vehicle or by means of at least one electric motor operating in its regeneration mode to brake the vehicle.

[0033] In another method step S2, the vehicle mass is estimated considering at least one torque value and one measurement value. Preferably, the vehicle mass is estimated using an estimation algorithm that repeats differential equations, including at least the torque value and the measurement value, at a predetermined frequency during time intervals. Refer to the description of the preceding embodiments for the algorithms and equations that may be used herein.

[0034] Figure 3A flowchart is shown to illustrate one embodiment of a method for braking a vehicle by means of at least one electric motor operating in its regeneration mode.

[0035] The vehicle / motor vehicle that is braked by means of at least one electric motor operating in its regeneration mode can be, for example, a PKW (passenger vehicle). However, it should be noted that the feasibility of the method described herein is not limited to a specific vehicle / motor vehicle type.

[0036] As can be seen in the flowchart, when executing the method described herein, the vehicle mass of the corresponding vehicle is first estimated by performing the method steps S1 and S2 explained above. Subsequently, in another method step S3, taking into account the estimated vehicle mass, at least one electric motor operating in its regeneration mode is manipulated to brake the vehicle by means of at least one electric motor. Unlike the conventional manipulation of at least one electric motor considering only a constant, pre-given mass for a single application, improved pre-control of at least one electric motor is possible in the method described herein. Since the regulator used to manipulate at least one electric motor operating in its regeneration mode hardly needs to operate, the efficiency and performance of the braking or parking process are significantly improved. This also improves the robustness of the braking or parking process.

[0037] Vehicle mass can often change drastically. However, this can be advantageously addressed by means of the method steps S1 to S3 described herein. In particular, by performing the method described herein, even after a drastic change in vehicle mass, a shock-like braking or stopping process and undesirable rollback of the vehicle can be avoided.

[0038] Advantageously, the active operation of at least one electric motor operating in its recycling mode can be maintained until the vehicle stops. Therefore, by means of... Figure 3 The graphical representation method is particularly well-suited to so-called "e-Braking to Zero," which brings the vehicle to a complete stop by means of at least one electric motor operating in regeneration mode. By utilizing the vehicle's mass, a very smooth experience is ensured when transitioning to a stop in the case of e-Braking to Zero. E-Braking to Zero works not only on flat surfaces but also when driving uphill or downhill.

[0039] However, Figure 3 This method can also be used in other regenerative braking processes. Because during regenerative braking, the kinetic energy of the braked vehicle is converted into electrical energy, this electrical energy can be stored in at least one battery in the vehicle for later use. Figure 3The method essentially helps to improve the energy efficiency of a vehicle, increase the driving range of at least one battery, avoid particulate matter and / or pollutant emissions, and / or reduce wear on its hydraulic braking system. By implementing regenerative braking, a significant portion of the kinetic energy that would otherwise be lost as heat or dust during braking can also be recovered.

Claims

1. An evaluation device (10) for vehicles, comprising: Electronic devices (12a, 12b), said electronic devices being designed and / or programmed to enable the generation of non-zero acceleration or deceleration torques (M2) applied to the vehicle by means of at least one braking and / or accelerating device of the vehicle within a time interval. activ At least one torque value (M) activ The vehicle mass (m) is estimated by simultaneously determining a measurement (a) of the change (a) caused by the speed (v) of the vehicle and the speed (v) of the vehicle; characterized in that, The electronic devices (12a, 12b) are additionally designed and / or programmed to enable the determination of the time interval by means of the electronic devices (12a, 12b), such that during the time interval, a non-zero acceleration or deceleration torque (M) is present. activ The vehicle is acted upon by means of at least one electric motor of the vehicle, which is at least part of the at least one braking and / or acceleration device, to drive the vehicle by means of the at least one electric motor or to brake the vehicle by means of at least one electric motor operating in its regeneration mode.

2. The evaluation apparatus (10) according to claim 1, wherein the electronic devices (12a, 12b) are additionally designed and / or programmed such that the vehicle mass (m) of the vehicle can be estimated by means of the electronic devices (12a, 12b) using an estimation algorithm that repeats at least the torque value (M) at a predetermined frequency during the time interval. activ The differential equations for (a) and the measured value (a).

3. The evaluation apparatus (10) according to claim 1 or 2, wherein the electronic devices (12a, 12b) are additionally designed and / or programmed to enable the determination of the time interval by means of the electronic devices (12a, 12b), such that during the time interval, a non-zero acceleration or deceleration torque (M) is applied to the vehicle by means of the at least one braking and / or acceleration device. activ At least 50% of the force is applied to the vehicle by means of the at least one electric motor.

4. The evaluation apparatus (10) according to claim 3, wherein the electronic devices (12a, 12b) are additionally designed and / or programmed to enable the determination of the time interval by means of the electronic devices (12a, 12b), such that during the time interval, a non-zero acceleration or deceleration torque (M) is applied to the vehicle by means of the at least one braking and / or acceleration device. activ At least 90% of the power is applied to the vehicle by means of the at least one electric motor.

5. The evaluation apparatus (10) according to any one of the preceding claims, wherein the electronic devices (12a, 12b) are additionally designed and / or programmed such that, by means of the electronic devices (12a, 12b), the time interval can be defined such that, during the time interval, the negative motor deceleration torque (M) is... m The vehicle is acted upon at least in part by means of at least one electric motor operating in its recycling mode.

6. A control device (16) for at least one electric motor of at least one vehicle that can operate in its recycling mode, comprising: The evaluation device (10) according to any one of the preceding claims; and The control electronics (18) is capable of outputting at least one motor control signal (20) to at least one motor, taking into account the vehicle mass (m) estimated by means of the evaluation device (10), so that the vehicle can be braked by means of at least one motor operating in its regeneration mode.

7. A method for estimating the vehicle mass (m) of a vehicle, comprising the following steps: Determine the non-zero acceleration or deceleration torque (M) applied to the vehicle by means of at least one braking and / or accelerating device within the time interval. activ At least one torque value (M) activ A simultaneously determined measurement (a) of the change in speed of the moving vehicle (a); and Considering the at least one torque value (M) activ Estimate the vehicle mass (m) in the case of one measurement (a) and one measurement (a) (S2); Its features are, Determine the at least one torque value (M) within the time interval. activ And a measurement (a) for each of the time intervals, such that the acceleration or deceleration torque (M) is not equal to zero. activ (S1) The vehicle is driven by at least one electric motor of the vehicle, which is at least part of the at least one braking and / or acceleration device, or the vehicle is braked by at least one electric motor operating in its regeneration mode.

8. The method of claim 7, wherein the vehicle mass (m) is estimated using an estimation algorithm, the estimation algorithm repeating at least the torque value (M) at a predetermined frequency during the time interval. activ The differential equations for (a) and the measured value (a).

9. A method for braking a vehicle by means of at least one electric motor operating in its regeneration mode, comprising the steps of: Estimate the vehicle mass (m) of the vehicle according to the method according to claim 7 or 8 (S1, S2); and Taking into account the estimated vehicle mass (m), the at least one electric motor operating in its recovery mode is manipulated to brake the vehicle by means of the at least one electric motor (S3).

10. The method of claim 9, wherein the active operation of the at least one electric motor operating in its recycling mode is maintained until the vehicle stops.

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