JPH054537B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention calculates the amount of load fluctuation based on a predetermined input signal, and calculates the optimum gear stage for fuel-efficient driving.
The present invention relates to an automobile shift change instruction device that determines shift change timing.

(Prior art and its problems) Modern automobiles are equipped with devices that instruct the driver how to operate the gear (upshift, downshift), but conventional shift change devices do not take into account the weight of the loaded object. As a result, in freight vehicles with large weight changes, it is not possible to accurately determine shift changes, making it impossible to ensure driving safety on steep slopes, and the optimum gear being not selected, resulting in poor fuel economy and poor economic performance. There were problems such as not being able to drive.

In order to deal with such problems,
A technique described in Publication No. 17725 (hereinafter referred to as prior art) has been proposed. In this prior art, as schematically shown in the block diagram of FIG.
Signals such as vehicle speed, throttle opening, loaded weight, and slope slope are input to an electronic control circuit 2 that includes a timer and memory. That is, by inputting the amount of load fluctuation such as the loaded weight and slope gradient into the electronic control circuit, a preset basic pattern is corrected based on the vehicle speed, and an output signal is sent to the gear shift instruction device 6. There is.

In this way, in the prior art, the basic pattern is corrected in accordance with load fluctuations, so it is necessary to detect the slope angle of the slope, which is the cause of the fluctuations. Furthermore, since the correction amount actually varies greatly for each gear, the correction amount must be inputted differently for each gear, which requires a complicated processing device, which is impractical. Furthermore, the improvement in fuel efficiency was not sufficient.

(Object of the Invention) Therefore, in order to determine whether a shift change is possible, the present invention calculates the change in vehicle speed or engine speed at a fixed time, that is, the acceleration of the vehicle, and calculates the obtained acceleration and the loaded weight, Then, calculate the amount equivalent to the running resistance from the engine driving force through calculation processing, and compare the fuel consumption rate at each gear to drive at a constant speed against the running resistance to see if it is possible to improve fuel efficiency by changing shifts. The purpose of the present invention is to provide a shift change instructing device for an automobile, which determines the optimum gear position and shift change timing by determining whether or not the vehicle is moving, thereby increasing the driving safety of the automobile and enabling fuel-efficient driving. It is something.

(Summary of the Invention) The shift change instruction device for an automobile of the present invention includes means for determining engine driving force according to engine speed and engine load, detecting vehicle acceleration from vehicle speed or engine speed, data, further comprising means for calculating running resistance from the engine driving force, and means for calculating a fuel consumption rate in a state where the engine driving force corresponding to the running resistance is generated when shifting to another gear. ing. When the gear where the fuel consumption rate is minimum is different from the current gear, a signal instructing a shift is output to the instruction device after a waiting time determined according to the gear, etc. It is something to do. In this way, the running resistance at that time is calculated from the acceleration of the vehicle, and the fuel consumption rate in an engine state that generates a driving force commensurate with this running resistance is determined for each gear stage. Therefore, it is possible to instruct fuel-efficient driving while ensuring driving performance.

(Example) Next, an example of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an overview of the present invention. Engine load signals based on engine speed, vehicle speed, ease position, amount of depression of the accelerator pedal, etc. are detected by well-known sensors and input to an electronic control circuit 2 that includes a timer and memory. In addition, signals from a load weight notification volume 4 and a final gear notification switch 5 are also input to the electronic control circuit 2 through operations by the driver. The electronic control circuit 2 performs necessary arithmetic processing, which will be described in detail later, and sends an output signal to a gear shift instruction device 6 in which LED display elements and the like are arranged based on the results of the arithmetic processing.
The LED display element displays shift change commands for upshifting and downshifting. The gear shift command signal is transmitted through an instruction sound speaker 3 using a piezoelectric speaker or the like.
A sound is also sent to the driver to instruct the driver to shift gears.

In this way, the electronic control circuit 2, the instruction sound speaker 3, the load volume volume 4, and the final gear notification switch 5 constitute the fuel-saving driving instruction device 1. FIG. 2 is a flowchart showing the processing procedure of the shift change control device according to the present invention. Before explaining this flowchart, the basic arithmetic processing of the present invention performed by the electronic control circuit 2 will be explained. In the memory of the electronic control circuit 2, the engine rotation speed (rpm) is taken as the Y axis, the engine load, for example, the rack position is taken as the analog voltage (V) on the X axis, and the Z axis shows the corresponding axial mean effective pressure PME.
A pattern indicating the value of (Pressure Mean Effective) [Kg/cm ² ] is stored as shown in FIG. Shaft mean effective pressure PME is one of the fundamental parameters of an engine, and is a quantity directly proportional to engine driving force, as will be described later. Depending on the engine speed and rack position when the car is running,
Search the PME value from the memory map and set the value at this time as PMEa. Let PMEc be the PME value required by the engine when the vehicle runs at a constant speed.
Comparing PMEc and PMEa, if PMEa>PMEc...(1) holds, the car is accelerating, and if PMEa<PMEc...(2) holds, the car is decelerating. .

Here, if the amount of change △PME in the shaft average effective pressure due to acceleration or deceleration is △PME=PMEa−PMEc ……(3), then PMEc=PMEa−△PME ……(4), and the △PME value is If it can be determined, the amount corresponding to running resistance, that is, PMEc can be found.

In the driving performance characteristic diagram shown in Figure 3, for example, when the driving force FA at point A is output by the 4th gear, if the driving resistance at the same vehicle speed VA is FLA, then the acceleration α is the total vehicle weight M Then, it is expressed as α=(FA−FLA)/M (5). Here, driving force FA, running resistance
When FLA is converted from the shaft average effective PME value output by the engine, FA=K ₁・(PMEa)・(μf・μf) ……(6) FLA=K ₁・(PMEc)・(μf・μf) …… (7) holds true. However, K ₁ : proportionality constant μf : final gear ratio μt : transmission gear ratio.

On the other hand, the acceleration α can be approximated as α=K ₂ ·(ΔV/ΔT) (8) where ΔV is the change in the vehicle speed V at every fixed time ΔT. However, K ₂ is a proportionality constant.
Also, the change in engine speed N for each △T is △
When N, △V=K ₃・(△N)/(μf・μt)...(9). However, K ₃ is a proportionality constant.

From the above, equation (4) can be expressed as PMEc=PMEa−[K ₄・M・(△N/△T)・(1/μf ²・μt ² )] ……(10). Here, if ΔT=1(s), it can be expressed as PMEc=PMEa−K ₅ ·K ₆ ·ΔN (11). Here, _K5 is a constant proportional to the loaded weight M declared by the driver, and the value from empty to constant load is determined. K ₆ is a constant determined by the gear used. Note that if ΔT is not 1(s), the constant K ₆ is corrected as follows: K6′=K ₆ ·(1/ΔT) (12).

The exact formula for each proportionality constant is K ₁ = η・v/4πR R: Effective radius of tire (cm) η: Power transmission efficiency v: Total engine displacement (cc) K ₂ = 1/9.8×3.6 K ₃ = 2πR×60/10 ⁵ K ₄ =1.34×10 ⁻³ ×R ² /v・△T K ₅ =(vehicle weight)+M K ₆ =1.34×10 ⁻³ ×R ² /v. For the vehicle speed VA in Figure 3, which is determined by equation (11)
FLA is the shaft average effective pressure required by the engine to balance the running resistance in 4th gear and drive the vehicle at a constant speed.

Shaft average effective pressure required by the engine in order for the vehicle to travel at a constant vehicle speed in balance with the same running resistance FLA at the same speed (VA) in other gears.
PME ₀ and engine speed N ₀ are determined from the relationship of gear ratio μ.

N ₀ = (μ ₀ / μu) Nu ... (13) PME ₀ = (μu / μ ₀ ) PMEc ... (14) where, μu: Gear ratio of the gear used μ ₀ : Gear ratio of other gears Nu: Engine speed at the gear used PMEc: Shaft average effective pressure required to balance running resistance at the gear used Next, the fuel consumption rate SFC (Specific Fuel
Consumption) pattern is stored in memory in advance as shown in Fig. 4, and N ₀ , obtained in (13) and (14),
From PME ₀ , search the fuel consumption rate SFC at all gears from the memory map.

Next, check whether the engine speed and shaft average effective pressure of each gear are appropriate for use (OK) or inappropriate (NG).
In order to determine whether this is the case, a data map as shown in FIG. 5 is searched in advance. If it is NG, that gear
Processing is performed to change the SFC value to the maximum value, but in the following gear stage determination, processing is performed that is not applicable.

Next, the gear position where the fuel consumption rate SFC value is the minimum is determined, and if the gear position is equal to the current gear position, it is determined as "OK", and if it is different, it is determined as "shift up" or "shift down". With the above processing,
Basic processing is performed to ensure fuel-efficient driving without running out of driving force.

Next, the flowchart shown in FIG. 2 will be explained.

(1) Initialize the fuel-saving driving instruction device 1 (step P ₁ ), and then drive for a certain period of time, for example, 65m.
After waiting for s to elapse (step P ₂ ), the process proceeds to sound output processing (step P ₃ ). The sound output here is the one determined in step _P17 .

(2) Next, the analog voltage at the rack position input to the electronic control circuit shown in FIG. 1 and 2 is processed for use as an engine load signal. Next, when the engine speed N is 0 in step _P5 , no further processing is performed, and the processing returns to step _P2 . This is because the shift change is determined only while the engine is operating.

(3) When the engine speed N is not 0 and is in operation,
Determine whether the vehicle speed is not 0 (step
_P6 ). When the vehicle speed is 0, the vehicle is stopped, so no further processing is performed. Next, the gear to be used is determined (step _P7 ). In step _P8 , it is determined whether the clutch is connected or not.
If the clutch is not engaged, step
At _P9 , set △N=0 and return to step _P2 .

(4) If the clutch is engaged, the value of the shaft average effective pressure PMEa during running is determined from the rack position signal L, which is the engine load, and the engine speed N (step _P10 ). Next, it is determined whether the engine brake is being used or the accelerator is being depressed (step _P11 ). Since fuel is not injected when engine braking is used in a diesel engine, there is no need to instruct a shift change, so the process returns to step _P2 .
If PMEa is smaller than a certain constant value, it is determined that the engine brake is being used, and if it is larger, it is determined that the accelerator is being depressed.

(5) Next, use equation (11) to find the shaft average effective pressure PMEc necessary for running while balancing the running resistance (step P ₁₂ ). Next, the engine speed N ₀ and shaft average effective pressure PME ₀ of the other gears are calculated using equations (13) and (14) (step P ₁₃ ). The obtained N ₀ value and
Fuel consumption rate for each gear relative to PME ₀ value
SFC(i)=G(N, PME) is searched from the memory map, and it is determined whether each gear stage N and PME are appropriate values, and the value of SFC is adjusted (step _P14 ). Furthermore, the gear with the minimum fuel consumption rate is determined, and if the gear determined as the minimum is equal to the currently used gear, "OK in the currently used gear", and if it is different, "shift up" or Determine "shift down" (step _P15 ). If the number of gears used is smaller than the number of gears at which SFC is the minimum, it is determined to be a "shift up", and if it is larger, it is determined to be a "downshift".

(6) The judgment result of step P ₁₅ is not output immediately, but a waiting time determined by the value of △PME and the gear used as shown in Fig. 6 is set so that appropriate instructions can be issued ( step
_P16 ). The waiting time has the effect of compensating for the reduction in vehicle speed during gear shifting. After the waiting time has elapsed, a shift change instruction signal of "shift up" or "shift down" is sent to the gear shift instruction device 6 (step
_P17 ).

(Effects of the Invention) As explained above, the shift change instructing device for an automobile of the present invention calculates the change in vehicle speed or engine speed at a fixed time, that is, the acceleration of the automobile, and uses the obtained acceleration and the loaded weight. Since the amount of load fluctuation is calculated through arithmetic processing and it is determined whether a shift change is possible, the configuration is simplified because there is no need for a slope slope signal as in the prior art.

In addition, by comparing the fuel consumption rate at each gear, it is determined whether or not it is possible to improve fuel efficiency by changing shifts, and the optimal gear and timing of shift changes are determined, thereby ensuring vehicle driving safety. This has the effect of increasing fuel efficiency and enabling fuel-efficient driving that cannot be achieved with prior art.

Further, since there is no need to add a correction amount to each gear to compensate for load fluctuations, the shift change determination process can be simplified.

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram of the present invention, FIG. 2 is a flowchart, FIGS. 3 to 7 are explanatory diagrams, and FIG.
The figure is a block diagram of a conventional example. 1...Fuel saving driving instruction device, 2...Electronic control circuit, 3...Instruction sound speaker, 4...Loaded weight declaration volume, 5...Final gear notification switch, 6...Gear shift instruction device.

Claims (1)

[Scope of Claims] 1. A shift change instructing device for instructing a driver to operate a gear in a transmission of an automobile, comprising means for determining engine driving force according to engine speed and engine load; means for detecting the acceleration of the vehicle, calculating running resistance from this data, vehicle weight data, and the engine driving force, and generating an engine driving force commensurate with the running resistance when shifting to another gear. and means for outputting a signal instructing a gear shift to an indicating device after a predetermined waiting time has elapsed when the gear position at which the fuel consumption rate is minimum is different from the current gear position. A shift change instruction device for an automobile, comprising: