MembersPage/Fuel

'Is this table suitable?'

Fuel pressure analog signal from sensor is calculated with:

Vout=(c1*Pabs+C0)*Us

With Vsupply at nominal 5V this means

With the req_fuel calculated at 255 kPa Fuelpressure the original PW is altered by 1/1 at Vsens_out = 2.843V

Gives the following look-up table:


# kPa	Vout	devision	multiplier
45.8	0.452	0	0.179607843
47.2	0.468	1	0.185098039
48.6	0.484	2	0.190588235
50	0.5	3	0.196078431
51.4	0.516	4	0.201568627
52.8	0.532	5	0.207058824
54.2	0.548	6	0.21254902
55.6	0.564	7	0.218039216
57	0.58	8	0.223529412
58.4	0.596	9	0.229019608
59.8	0.612	10	0.234509804
61.2	0.628	11	0.24
62.6	0.644	12	0.245490196
64	0.66	13	0.250980392
65.4	0.676	14	0.256470588
66.8	0.692	15	0.261960784
68.2	0.708	16	0.26745098
69.6	0.724	17	0.272941176
71	0.74	18	0.278431373
72.4	0.756	19	0.283921569
73.8	0.772	20	0.289411765
75.2	0.788	21	0.294901961
76.6	0.804	22	0.300392157
78	0.82	23	0.305882353
79.4	0.836	24	0.311372549
80.8	0.852	25	0.316862745
82.2	0.868	26	0.322352941
83.6	0.884	27	0.327843137
85	0.9	28	0.333333333
86.4	0.916	29	0.338823529
87.8	0.932	30	0.344313725
89.2	0.948	31	0.349803922
90.6	0.964	32	0.355294118
92	0.98	33	0.360784314
93.4	0.996	34	0.36627451
94.8	1.012	35	0.371764706
96.2	1.028	36	0.377254902
97.6	1.044	37	0.382745098
99	1.06	38	0.388235294
100.4	1.076	39	0.39372549
101.8	1.092	40	0.399215686
103.2	1.108	41	0.404705882
104.6	1.124	42	0.410196078
106	1.14	43	0.415686275
107.4	1.156	44	0.421176471
108.8	1.172	45	0.426666667
110.2	1.188	46	0.432156863
111.6	1.204	47	0.437647059
113	1.22	48	0.443137255
114.4	1.236	49	0.448627451
115.8	1.252	50	0.454117647
117.2	1.268	51	0.459607843
118.6	1.284	52	0.465098039
120	1.3	53	0.470588235
121.4	1.316	54	0.476078431
122.8	1.332	55	0.481568627
124.2	1.348	56	0.487058824
125.6	1.364	57	0.49254902
127	1.38	58	0.498039216
128.4	1.396	59	0.503529412
129.8	1.412	60	0.509019608
131.2	1.428	61	0.514509804
132.6	1.444	62	0.52
134	1.46	63	0.525490196
135.4	1.476	64	0.530980392
136.8	1.492	65	0.536470588
138.2	1.508	66	0.541960784
139.6	1.524	67	0.54745098
141	1.54	68	0.552941176
142.4	1.556	69	0.558431373
143.8	1.572	70	0.563921569
145.2	1.588	71	0.569411765
146.6	1.604	72	0.574901961
148	1.62	73	0.580392157
149.4	1.636	74	0.585882353
150.8	1.652	75	0.591372549
152.2	1.668	76	0.596862745
153.6	1.684	77	0.602352941
155	1.7	78	0.607843137
156.4	1.716	79	0.613333333
157.8	1.732	80	0.618823529
159.2	1.748	81	0.624313725
160.6	1.764	82	0.629803922
162	1.78	83	0.635294118
163.4	1.796	84	0.640784314
164.8	1.812	85	0.64627451
166.2	1.828	86	0.651764706
167.6	1.844	87	0.657254902
169	1.86	88	0.662745098
170.4	1.876	89	0.668235294
171.8	1.892	90	0.67372549
173.2	1.908	91	0.679215686
174.6	1.924	92	0.684705882
176	1.94	93	0.690196078
177.4	1.956	94	0.695686275
178.8	1.972	95	0.701176471
180.2	1.988	96	0.706666667
181.6	2.004	97	0.712156863
183	2.02	98	0.717647059
184.4	2.036	99	0.723137255
185.8	2.052	100	0.728627451
187.2	2.068	101	0.734117647
188.6	2.084	102	0.739607843
190	2.1	103	0.745098039
191.4	2.116	104	0.750588235
192.8	2.132	105	0.756078431
194.2	2.148	106	0.761568627
195.6	2.164	107	0.767058824
197	2.18	108	0.77254902
198.4	2.196	109	0.778039216
199.8	2.212	110	0.783529412
201.2	2.228	111	0.789019608
202.6	2.244	112	0.794509804
204	2.26	113	0.8
205.4	2.276	114	0.805490196
206.8	2.292	115	0.810980392
208.2	2.308	116	0.816470588
209.6	2.324	117	0.821960784
211	2.34	118	0.82745098
212.4	2.356	119	0.832941176
213.8	2.372	120	0.838431373
215.2	2.388	121	0.843921569
216.6	2.404	122	0.849411765
218	2.42	123	0.854901961
219.4	2.436	124	0.860392157
220.8	2.452	125	0.865882353
222.2	2.468	126	0.871372549
223.6	2.484	127	0.876862745
225	2.5	128	0.882352941
226.4	2.516	129	0.887843137
227.8	2.532	130	0.893333333
229.2	2.548	131	0.898823529
230.6	2.564	132	0.904313725
232	2.58	133	0.909803922
233.4	2.596	134	0.915294118
234.8	2.612	135	0.920784314
236.2	2.628	136	0.92627451
237.6	2.644	137	0.931764706
239	2.66	138	0.937254902
240.4	2.676	139	0.942745098
241.8	2.692	140	0.948235294
243.2	2.708	141	0.95372549
244.6	2.724	142	0.959215686
246	2.74	143	0.964705882
247.4	2.756	144	0.970196078
248.8	2.772	145	0.975686275
250.2	2.788	146	0.981176471
251.6	2.804	147	0.986666667
253	2.82	148	0.992156863
254.4	2.836	149	0.997647059
255.8	2.852	150	1.003137255
257.2	2.868	151	1.008627451
258.6	2.884	152	1.014117647
260	2.9	153	1.019607843
261.4	2.916	154	1.025098039
262.8	2.932	155	1.030588235
264.2	2.948	156	1.036078431
265.6	2.964	157	1.041568627
267	2.98	158	1.047058824
268.4	2.996	159	1.05254902
269.8	3.012	160	1.058039216
271.2	3.028	161	1.063529412
272.6	3.044	162	1.069019608
274	3.06	163	1.074509804
275.4	3.076	164	1.08
276.8	3.092	165	1.085490196
278.2	3.108	166	1.090980392
279.6	3.124	167	1.096470588
281	3.14	168	1.101960784
282.4	3.156	169	1.10745098
283.8	3.172	170	1.112941176
285.2	3.188	171	1.118431373
286.6	3.204	172	1.123921569
288	3.22	173	1.129411765
289.4	3.236	174	1.134901961
290.8	3.252	175	1.140392157
292.2	3.268	176	1.145882353
293.6	3.284	177	1.151372549
295	3.3	178	1.156862745
296.4	3.316	179	1.162352941
297.8	3.332	180	1.167843137
299.2	3.348	181	1.173333333
300.6	3.364	182	1.178823529
302	3.38	183	1.184313725
303.4	3.396	184	1.189803922
304.8	3.412	185	1.195294118
306.2	3.428	186	1.200784314
307.6	3.444	187	1.20627451
309	3.46	188	1.211764706
310.4	3.476	189	1.217254902
311.8	3.492	190	1.222745098
313.2	3.508	191	1.228235294
314.6	3.524	192	1.23372549
316	3.54	193	1.239215686
317.4	3.556	194	1.244705882
318.8	3.572	195	1.250196078
320.2	3.588	196	1.255686275
321.6	3.604	197	1.261176471
323	3.62	198	1.266666667
324.4	3.636	199	1.272156863
325.8	3.652	200	1.277647059
327.2	3.668	201	1.283137255
328.6	3.684	202	1.288627451
330	3.7	203	1.294117647
331.4	3.716	204	1.299607843
332.8	3.732	205	1.305098039
334.2	3.748	206	1.310588235
335.6	3.764	207	1.316078431
337	3.78	208	1.321568627
338.4	3.796	209	1.327058824
339.8	3.812	210	1.33254902
341.2	3.828	211	1.338039216
342.6	3.844	212	1.343529412
344	3.86	213	1.349019608
345.4	3.876	214	1.354509804
346.8	3.892	215	1.36
348.2	3.908	216	1.365490196
349.6	3.924	217	1.370980392
351	3.94	218	1.376470588
352.4	3.956	219	1.381960784
353.8	3.972	220	1.38745098
355.2	3.988	221	1.392941176
356.6	4.004	222	1.398431373
358	4.02	223	1.403921569
359.4	4.036	224	1.409411765
360.8	4.052	225	1.414901961
362.2	4.068	226	1.420392157
363.6	4.084	227	1.425882353
365	4.1	228	1.431372549
366.4	4.116	229	1.436862745
367.8	4.132	230	1.442352941
369.2	4.148	231	1.447843137
370.6	4.164	232	1.453333333
372	4.18	233	1.458823529
373.4	4.196	234	1.464313725
374.8	4.212	235	1.469803922
376.2	4.228	236	1.475294118
377.6	4.244	237	1.480784314
379	4.26	238	1.48627451
380.4	4.276	239	1.491764706
381.8	4.292	240	1.497254902
383.2	4.308	241	1.502745098
384.6	4.324	242	1.508235294
386	4.34	243	1.51372549
387.4	4.356	244	1.519215686
388.8	4.372	245	1.524705882
390.2	4.388	246	1.530196078
391.6	4.404	247	1.535686275
393	4.42	248	1.541176471
394.4	4.436	249	1.546666667
395.8	4.452	250	1.552156863
397.2	4.468	251	1.557647059
398.6	4.484	252	1.563137255
400	4.5	253	1.568627451
401.4	4.516	254	1.574117647
402.8	4.532	255	1.579607843

Plotting the above with gnuplot

plot 'pres.dat' using 3:4 with lines title 'multiplier', 'pres.dat' using 3:($1/100) with lines title '*100 kPa', 'pres.dat' using 3:2 with lines title 'Vout'

pressure_JanSaenen.png

shows that it's all linear. (note that pressure was plotted in bar using 1/100 so all curves fit on same graph, same y axis range).

Why do we need the lookup than? Simple slope and offset can be used the same way as for MAP kpafac and kpaoffs.